Biomechanics Thesis
Abstracts
since 1986
(Last updated: 11 March
2009)
Links to student abstracts are listed
alphabetically
by author:
- Mouafak
Al Hadi Motion of the foot inside a hockey skate as
measured
from bone, skin and skate markers.
- John M. Barden
Validation of an inverse dynamics method to predict joint kinetics in
the
absence of dynamometry.
- François
Gaston D. Beaulieu Biomechanical analysis of two methods of
descending
stairs.
- Melanie Beaulieu
- Étienne
Bisson Les effets de l’entraînement avec biofeedback
visuel
et de l’entraînement en réalité visuelle sure la
demande
attentionnelle et l’équilibre chez les personnes
âgée.
- Michael Anthony
Blench Trunk balance in stroke: The effects of right and left
cerebral
lesions.
- Lynn Tony Casimiro Feedforward
postural
adjustments associated with a goal-directed reach produced by infants
in
the sitting and standing positions.
Tyler
Cluff Kinetic
analysis of forwards,
step-by-step and backwards stair descent.
- Rodrigo Mascarenhas
Corrêa L'influence de quatre deplacement sagittaux des
membres
inferieurs sur l'electromyographie et sur la position de la colonne
lombaire
lors de la posture debout quasi statique.
- Alison Cronin
Effect of selected ankle supports on resistance to inversion force and
range of motion.
- Daniel Thomas
Curry Lower limb muscle function during cycling.
- Sébastien Delorme Biomechanical
analysis of ankle injuries in
snowboarding.
- Marlene
Eckstrand Trunk balance in stroke: The effects of right and
left
cerebral lesions on the sensory and motor components of response to
tilt.
- Yves D. Fortin
Lower extremity muscle function during ergometer rowing.
- Genille
Gimbel
- Benoît
Giroux Net shoulder joint moment and muscular activity during
light
weight handling at different heights and frequencies.
- Yves
Goyette
- Sylvain
Grenier Internal work measurement and simultaneous oxygen
consumption
of impaired and normal walking.
- Martin
Héroux Cortico-motor adaptations and proprioceptive
acuity
in patients with unilateral anterior cruciate ligament deficiency.
- Marshall
Kendall Calculation of the residual error in three-dimensional
videography using stationary, panning and mobile video capturing
techniques.
- Mathew
Kennedy
- Natasha
Flemming Kyle Muscle activation patterns during gait initiation.
- Dany
Lafontaine
- Chantal
M. Lafrenière Masticatory muscle activities in
temporomandibular
joint internal derangement.
- Leslie
Lamb
- Edward Donat
Lemaire Computer simulation of planar airborne human motions.
- Joe
Lynch Kinetics of planned and unplanned gait termination
- Louise Mâsse
Kinematic and electromyographic analysis of wheelchair propulsion for
various
seating positions.
- Jennifer McGregor Feedforward
postural adjustments
associated with unilateral rapid arm motion in children aged 4 and 5
years
and 10 and 11 years.
- Nicoleta
Marhao-Bugnario
- Steven R. McFaull Measurement and
statistical
analysis of the passive viscoelastic properties of the human knee joint
during flexion and extension motion.
- Annie-Claude
Mireault Contribution de l’information tactile à la
stabilité
posturale chez la population âgée.
- Stephen D.
Murphy Mathematical model of the sprint relay race.
- Kasey Parker
- Andrew Post Biomechanical
comparison of stair and ramp descent.
- Stefan
Potoczny Toddler gait: Comparison of toddler and adult joint
kinetics
of gait.
- Sheila B.A.
Purkiss Comparison of methods for calculating internal work of
elite running.
- Kerry
Keshwar Rambarran Effectiveness of the Kinetic Wedge foot
orthoses modification
to improve gait posture.
- Dan K. Ramsey An in vivo
three-dimensional
kinematic analysis of the anterior cruciate deficient knee.
- Phillipe
Rousseau
- Kevin M. Semeniuk Comparison of
mechanical
energy expenditure and mechanical efficiency of normal walking at
various velocities.
- Jonathan
Singer Functional knee brace
migration:
Biomechanical and neuromuscular alterations.
- Vivian-Lee
Stewart Influence of block angle and diver stance on power
production
and takeoff velocity in swim starting.
- Taunya
Allyson St. Pierre Modelling the muscles of the lower
extremity:
The effect of varying joint angles on muscle length.
- Fary
Taffazoli Mechanical behaviour of hamstring muscles and hip
joint
in low-back pain and control subjects.
- Daniel
Theoret
- Marianne
Thornton Balance training using virtual reality as compared to
an activity-based exercise program for adults with traumatic brain
injury.
- Patricia
A. Turnbull Contrast of methods for calculating internal work
of
running for trained and untrained runners.
- Lori Ann Vallis
Infant bouncing: Analysis of skilled and less-skilled behaviour.
- Greg G. Weames
Comparison of the 1991 NIOSH lifting equation and erector spinae muscle
electromyography.
- Jean-Marie
John Wilson Lower limb muscle function during deep-knee bending.
- Robyn Melissa Wharf
Locomotor
adaptations to changes of incline ascent gradient.
Alphabetical
List
of Abstracts:
Motion of the foot inside a
hockey skate
as measured from bone, skin and skate markers.
Author: Mouafak Al Hadi
Degree: M.Sc.
Year: 2002
Supervisor: Mario Lamontagne
Department: Anatomy and Neurobiology
Institution: University of Ottawa
To
index
Abstract: The present study aims at exploring differences amongst bone,
skin, and skate marker based rotations of the foot during skating.
Three
holes were made in a right hockey skate above the tarsal bones, and
three
plastic screws with lead markers were attached to a piece of
thermoplastic
molded to the area of the skin below the holes. The lead markers
protruded
from the skate. Three other lead markers were attached to the skate
boot.
Five subjects participated in the experiment where the foot inside the
skate was X-rayed within a calibration cage. Two X-ray shots with 30o
angle
between them were taken of the still foot in fulldorsiflexion, neutral,
and full plantar flexion with 45° of external rotation. Three bony
landmarks were established on the tarsal bones in each image. The lead
markers and the three bony landmarks were digitized using Ariel
Performance
Analysis System. A vector that passes through two markers on the
bone, a vector that passes through two markers on the skin, and a
vector
that passes through two markers on the skate were used to represent
foot
rotations from dorsiflexion to neutral position and from neutral
position
to plantar flexion. Paired samples t-tests were used to compare the
rotations
of different vectors to each other. The results showed that a
significant
difference amongst bone, skin, and skate rotations existed during
plantar
flexion but not during dorsiflexion. This significant difference
extended
to the total motion from dorsiflexion to plantar flexion where skate
rotations
were 26% smaller than bone rotations and 49% smaller than skin
rotations.
Bone rotations were 31% smaller than skin rotations. Based on the
results
of this study, it can be concluded that, unlike shoe motion, the
rigidity
of the skate structure causes the skate motion to underestimate the
motions
of bone and skin.
Validation of an inverse dynamics
method
to predict joint kinetics in the absence of dynamometry.
Author: John M. Barden
Degree: M.Sc.
Year: 1993
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: When investigating the joint kinetics of human locomotion,
ground reaction forces are typically measured directly using a force
platform.
In many different skills and movement environments, the utilization of
a force platform to collect external force data is not possible. These
particular movement situations require an indirect method to estimate
joint
kinetic variables if they are to be analyzed. This study investigated
whether
or not an eleven segment, complete body model could be used to
accurately
predict the net joint reaction forces and moments of force from
cinefilm
and body segment parameter data, using force platform calculated net
joint
reaction forces and moments of force as the criterion for validation.
The
body was modelled as a linked system of pin-connected rigid bodies and
was restricted to the sagittal plane analysis of single support
locomotion.
The movements analyzed for three subjects were jogging, running, the
acceleration
phase of sprinting, the long jump takeoff and a running front
somersault
into a forward roll. Displacement and ground reaction force data were
both
sampled at 100 Hz and low-pass filtered at cutoff frequencies of 6 and
10 Hz, respectively. The film predicted, support limb net joint
reaction
forces and moments of force were compared to the force platform
calculated
results using RMSE and Pearson product moment correlation statistics to
quantify phase and magnitude variations. It was found that vertical net
joint reaction forces can be estimated from displacement data using the
inverse dynamics approach and a complete body segment model. Limited
success
was attained in estimating the horizontal net joint reaction forces. No
consistent results were obtained in estimating the net joint moments of
force. Further refinements are necessary if net joint moments are to be
predicted accurately using this particular method.
Biomechanical analysis of two
methods
of descending stairs.
Author: François Gaston D. Beaulieu
Degree: M.A.
Year: 2004
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The activity of descending stairs increases loading at the
joints
of the lower extremities (Andriacchi et al., 1980) as compared to
walking
(McFadyen and Winter, 1988), which may cause certain discomfort and or
difficulties in completing the task. This study compared and contrasted
the kinematics and kinetics of forward and backward stair descent. We
compared
the support moment and moment powers of the lower limb joints while
descending
stairs in both types of scenario and secondly, performed an analysis of
the position of the foot on the step (ground reaction forces) to
determine
which method was more likely to reduce the risk of a slipping. Ten
subjects
(6 men and 4 women) with diverse heights (1.65 m ± 3 cm, 1.73 m
± 3 cm, and 1.80 m ± 3 cm) and between the ages of 20 and
35 were studied. Sagittal plane kinematics and forces were collected
and
angular moments calculated through an inverse dynamics approach.
Kinematics
and kinetics for forward and backward stair descent were contrasted to
level walking (Winter, 1991). The change in ratio of stance/swing phase
changed from Winter’s 60:40 normal level walking to between 65:35 and
70:30
in stair descent. Larger double peak support moments with reduced ankle
plantar flexor and increased knee extensor moments were found. The hip
moments were relatively small and highly variable. The horizontal
position
ground reaction force define movement to the edge of the step showed a
significant increase (P<0.001) for backward stair descent versus
forward
stair descent. Average stair descent cycle duration reduced when
descending
backward (1.134 s) compared to forward descent (1.349 s) (P<0.03).
There
was a significantly reduced peak knee extensor eccentric power
(P=0.005)
with backwards descent. These results demonstrate that stair descent
(forward
and backward) requires higher moments at the knee than level walking
but
backward descent demand less peak knee moment and eccentric power than
forward descent.
The effects of wearing work boots
on
lumbar spine flexion.
Author: Michael Anthony Blench
Degree: M.Sc.
Year: 1998
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The unilateral muscle activity of the erector spinae muscles,
hip extensors, knee extensors, ankle dorsiflexors and plantar flexors,
along with joint articulation kinematics of the ankle, knee, hip and
lumbar
region in the sagittal plane, were examined as a multi-link system. The
objective was to determine the effects of wearing work boots on joint
kinematics
with particular emphasis on the lumbar angle formed by the spinous
processes
of S3-L3-T10. Seventeen male subjects volunteered to perform specific
'repeated
measures'
exercises of a material handling nature while wearing properly laced
work
boots and barefoot with the feet on boot wedges but in an unbound
state.
Differences in relative angles, and EMG magnitude and timing were
examined.
The results obtained provide considerable understanding of the more
global
effects of joint restriction caused by the wearing of necessary
workplace
apparel. Peak amplitude normalized EMG revealed nothing of
significance.
Time normalized EMG showed that with the grasping of the container's
handles,
both the multifidus and biceps femoris had significant differences
between
wedging and booting, both displaying less muscle recruitment with the
wedge.
Non-normalized EMG demonstrated high degrees of significance in all
muscles
except the gastrocnemius, again, with the wedge scenario generally
demanding
less muscle recruitment. The X,Y-values of the centre of mass were
examined
and there was significance in the Y-value while no significant changes
were obtained in the lumbar angle. There were significant differences
in
the absolute trunk angle (defined as the angle formed by the spinous
processes
of T10-S3 and the horizontal) and that of the ankle. Although the
lumbar
angle did not change, the absolute trunk angle decreased significantly
with the wearing of laced work boots. This is a result of compensation
for the reduced articulation of the ankle. Reduction of the absolute
trunk
angle increases the torque on the spine which could cause cumulative
micro
trauma for those individuals having to wear work boots as the mainstay.
Les effets de
l’entraînement avec
biofeedback visuel et de l’entraînement en réalité
visuelle sure la demande attentionnelle et l’équilibre chez les
personnes âgées.
Author: Étienne Bisson
Degree: M.A.
Year: 2004
Supervisor: Yves Lajoie
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Résumé: Différents types d’entraînements
sont
disponibles pour améliorer la qualité de vie des
personnes
âgées. Cependant, l’entraînement le plus efficace
pour
améliorer l’équilibre et diminuer le risque de chuter
demeure
une question actuelle. Il a été démontré
qu’un
entraînement par biofeedback visuel peut améliorer
l’équilibre
et la demande d’attention des personnes âgées. Et
d’après
les études avec les patients cardiaques et ceux souffrant d’un
traumatisme
crânien, un entraînement par réalité
virtuelle
pourrait être bénéfique pour l’entraînement
de
l’équilibre chez les personnes âgées. Le but de
cette
étude était de comparer l’efficacité d’un
entraînement
d’équilibre dynamique par réalité virtuelle et par
biofeedback visuel pour améliorer l’équilibre et la
demande d’attention des personnes âgées. Au total, 24
personnes
âgées en bonne santé ont participé à
un programme d’entraînement de 10 semaines à une
fréquence
de 3 fois par semaines. Les sujets s’entraînant par
réalité
virtuelle (n=12) devaient jongler avec un ballon virtuel alternant de
gauche
à droite de façon imprévisible. Les sujets
s’entraînant
par biofeedback visuel (n=12) devaient diriger leur centre de pression
représenté par un point rouge vers quatre coins d’un
rectangle,
présenté sur un moniteur. Les personnes
âgées
des deux groupes ont amélioré significativement leur
score
au test d’équilibre fonctionnel « Community Balance and
Mobility
» et leur temps de réaction sans toutefois
améliorer
leurs oscillations posturales. Les deux types d’entraînement ont
alors été efficace pour améliorer
l’équilibre
des personnes âgées en améliorant leurs
habiletés
fonctionnelles et en diminuant la quantité d’attention
nécessaire
au maintien de l’équilibre. Conséquemment, les personnes
âgées participant à ces types d’entraînement
ont plus d’attention disponible pour analyser leur environnement
externe
et ainsi réduire les risques de chuter.
Feedforward postural adjustments associated
with a
goal-directed
reach produced by infants in the sitting and standing positions.
Author: Lynn Tony Casimiro (nee Bourdeau)
Degree: M.A.
Year: 2000
Supervisor: Heidi Sveistrup
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Two mechanisms of postural control, feedback and feedforward
are implicated for the maintenance of independent sitting and standing
postures. More specifically, feedback mechanisms encompass all
postural
reactions produced to maintain equilibrium in response to an unexpected
perturbation. Perturbations induced by a voluntary movement are
controlled
by feedforward mechanisms. The purpose of this study was to
characterize
feedforward postural adjustments produced by infants in the sitting and
standing positions. Twenty-two infants between the ages of 6 to 18
months
were tested using a goal-directed reach paradigm. Infants were
separated
in two behavioral groups, sitters and creepers. Surface
electromyography,
center of pressure displacement and video data were collected. Sitters
and creepers showed no consistent patterns of postural muscle
activation
or differences in postural muscle onset latencies. Compared to sitters,
creepers showed a greater proportion of trials with more than one
postural
muscle activated (p<0.05) and reached more slowly (p<0.05) in the
sitting position. A descriptive analysis of the data revealed a large
number
of trials with tonic postural muscle activity in the sitters group,
which
tended to be progressively replaced by phasic postural muscle activity
in the creepers group. It is possible that infants initially use tonic
postural muscle activity for postural control and develop more phasic
postural
muscle activity as they mature and gain experience in the sitting and
standing
positions. The reduction in reaching speed in the creepers group may be
an early movement strategy used to minimize the self-induced
perturbation
caused by goal-directed reaching.
L'influence de quatre deplacement
sagittaux
des membres inferieurs sur l'electromyographie et sur la position de la
colonne lombaire lors de la posture debout quasi statique.
Author: Rodrigo Mascarenhas Corrêa
Degree: M.Sc.
Year: 1993
Supervisor: D. Parry
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Résumé: Le but de cette étude est d'analyser
l'influence
de quatre déplacements sagittaux des articulations du genou et
de
la cheville sur l'activité myoélectrique
normalisée
de certains muscles antigravitaires, et sur la position de la colonne
lombaire
lors de la posture debout quasi statique. Deux positions angulaires du
genou et deux déplacements de la projection de la ligne de
gravité
(faits à partir de l'articulation de la cheville) sont
analysés.
La posture debout naturelle (telle que choisie par le sujet) a
été
utilisée comme posture témoin et facteur de
normalisation.
Le déplacement de la ligne de gravité a été
mesurée par rapport à la colonne lombaire (niveau L3) et
aux membres inférieurs. L'analyse électromyographique a
permis
de connaître l'activité myoélectrique
normalisée
des muscles antigravitaires suivants: para-vertébraux lombaires
au niveau de L3, grand droit de l'abdomen au niveau de l'ombilic, droit
antérieur, biceps fémoral, tibial antérieur et
gastrocnémien.
Les résultats démontrent: 1) une
variation
significative (P < 0.05) de VEMGN des muscles para-vertébraux
lombaires, droit antérieur de la cuisse et tibial
antérieur
et; 2) un lien entre les moyennes de VEMGN des para-vertébraux
et
la position de L3, entre les moyennes de VEMGN des
para-vertébraux
lombaires et VEMGN des abdominaux, entre les moyennes de VEMGN des
abdominaux
et la position de L3, entre les moyennes de VEMGN du muscle tibial
antérieur
et la position de la cheville, et entre VEMGN du muscle droit
antérieur
de la cuisse et la position de la cheville.
Les résultats de cette étude
permettent
d'arriver aux conclusions suivantes: 1) Pour les postures debout qui
ont
été analysées, VEMGN des muscles
para-vertébraux
lombaires diminue dans la mesure où l'écart entre L3 et
la
PCG augmente. 2) Dans une posture debout avec les genoux en
hyperextension
et la PCG tombant devant les malléoles externes, VEMGN des
muscles
para-vertébraux lombaires est plus grande que VEMGN dans une
posture
semblable avec la PCG tombant sur les malléoles externes. Elle
est
aussi plus grande dans une position debout avec les genoux
fléchis,
la PCG tombant soit sur les malléoles externes, soit devant les
malléoles externes. 3) Dans la posture debout avec les genoux
fléchis
à dix degrés, VEMGN des para-vertébraux lombaires
et la distance sagittale entre L3 et la PCG ont tendance à
être
semblables à celles trouvées dans une posture debout
naturelle.
4) Les déplacements sagittaux de la cheville ont une influence
sur
le rôle antigravitaire des muscles tibial antérieur et
droit
antérieur.
Effect of selected ankle supports
on
resistance to inversion force and range of motion.
Author: Alison Cronin
Degree: M.A.
Year: 2001
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Ankle injuries account for 15-60% of all volleyball injuries
(Briner & Benjamin, 1999). The majority of injuries are sprains
caused
by excessive inversion which stretch and tear the lateral ligaments of
the ankle. The incidence of reoccurrence and chronic instability is
very
high. Ankle braces have been designed to protect ankles from injuries
by
limiting inversion range of motion and supporting weakened ligaments.
High-top
volleyball shoes were also created to provide additional support to the
ankle and prevent injury during play. The mechanism by which these
supports
prevent injury had not been quantitatively measured. The purpose of
this
study was to determine if the ankle supports chosen were able to
provide
increased resistance to inversion, as measured by moment of force,
without
limiting plantar flexion or dorsiflexion. Resistance to inversion
moment
of force was measured on an isokinetic dynamometer (Kin-Com) in passive
mode, for six support conditions (combinations of low-top (LT) and
midcut
(MC) shoes with semi-rigid and flexible orthoses). The braces used were
the Active Ankle T1 Trainer (AA) and the Ankle Stabilizing Orthosis
(ASO).
The shoes were ASICS Gel Airier volleyball shoes in low-top and midcut
models. It was found that there was a significant difference in
resistance
to inversion moment of force mean, between the MC alone and the LT with
AA. The MC and brace combinations provided less resistance to
inversion.
The construction of the midcut shoe may have interfered with the brace,
inhibiting its performance. Plantar flexion (F(5,145) = 8.264) and
dorsiflexion
(F(5,145) = 8.264) range of motion were decreased in the MC conditions.
These did not impede normal parameters for walking. It was concluded
that
the best support condition was the combination of LT and AA. It
decreased
sagittal range of motion the least and provided increased force to
resist
inversion as compared to the control condition (LT).
Lower limb muscle function during
cycling
Author: Daniel T. Curry
Degree: M.Sc.
Year: 1990
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of this study was to describe the functional
role of the lower limb musculature during stationary cycling using
electromyography,
muscle-tendon unit length changes, and segmental kinematics. Five
subjects
were filmed (100 Hz) in synchrony with the collection of LE EMG
activity
of the gluteus maximus, semitendinosus, semimembranosus, rectus
femoris,
vastus lateralis, soleus, gastrocnernius, and tibialis anterior muscles
during stationary cycling at 160 W (90 r/min). The results showed that
extension during the propulsive phase of the pedal cycle was the result
of high concentric activity of both the monoarticular and biarticular
muscles.
Furthermore, these muscles functioned according to their expected
anatomical
roles (Rasch and Burke, 1978). This investigation, therefore, finds
little
evidence for the existence of paradoxical muscle function as
hypothesized
by Lombard (1903), Molbech (1965), or Rasch & Burke (1978).
Title.
Author: Nicoleta Marhao-Bugnario
Degree: M.A.
Year: 2002
Supervisor: Heidi Svestrup
Department: Anatomy and Neurobiology
Institution: University of Ottawa
To
index
Abstract:
Trunk balance in stroke: The
effects
of right and left cerebral lesions on the sensory and motor components
of response to tilt.
Author: Marlene Eckstrand
Degree: M.Sc.
Year: 1997
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of the study was to evaluate motor and sensory
components of trunk control in individuals with unilateral cerebral
stroke
and to identify differences in response between right and left sided
lesions.
Eighteen subjects, who were unstable in standing or unable to stand
were
tested. There were 9 subjects with right hemiplegia and 9 subjects with
left hemiplegia for the motor testing and 8 subjects in each group for
the sensory testing. Subjects were tested on a motorized seat that
could
be tilted approximately 150 to either side at a controlled velocity.
Reflective
markers were placed on the subject on the seat. The subjects' responses
were videotaped and digitized to compute the segmental kinematics.
The motor response was tested by tilting the seat
to each side and recording the response to maintain the upright
position.
Both the trunk movement relative to the starting position and the end
position
of the trunk relative to the vertical were calculated. The sensory
response
was tested by tilting the seat to the side and asking the subject to
indicate
when the seat felt level as it returned slowly to the horizontal. All
trials
were done three times to each side with eyes open and eyes closed.
Clinical
data was collected on motor function and sensation of the leg, lateral
trunk strength, lateral pelvic alignment, neglect, spatial deficits and
apraxia.
1) There is a greater deficit in the motor response
of the subjects with right hemiplegia than in subjects with left
hemiplegia
on tilt to the normal side (using muscles on the hemiplegic side). This
difference is seen in the end position of the trunk relative to the
vertical
and suggests a reduced motor response in right hemiplegia, using the
hemiplegic
trunk muscles. Compared to subjects with left hemiplegia.
2) The deficit in the motor response of the subjects
with right hemiplegia is greater on tilt to the normal side (using
muscles
on the hemiplegic side) than on tilt to the hemiplegic side (using
muscles
on the normal side). This difference is seen in the end position of the
trunk relative to the vertical and suggests a reduced motor response on
the hemiplegic side compared to the normal side in right hemiplegia.
3) The deficit in the motor response of the subjects
with left hemiplegia is greater on tilt to the hemiplegic side (using
muscles
on the normal side) than on tilt to the normal side using muscles on
the
hemiplegic side). This difference cannot be explained on the basis of
trunk
strength as the lesser reaction is with the hemiplegic trunk.
4) The deficit in perception of the seat as
horizontal
is greater in subjects with left hemiplegia than in subjects with right
hemiplegia from tilt to the hemiplegic side. Perception of the seat as
horizontal for subjects with left hemiplegia is displaced to the
hemiplegic
side. This may explain the lesser motor response of the trunk when
tilted
to the hemiplegic side (even though the normal side of the trunk is
active).
The subject may sense the vertical to be displaced to the hemiplegic
side
and does not respond appropriately to the true vertical.
5) Eye closure was expected to result in a greater
deficit in both the motor and sensory response in subjects with left
hemiplegia
than in subjects with right hemiplegia but this was not a significant
interaction.
Lower extremity muscle function
during
ergometer rowing.
Author: Yves D. Fortin
Degree: M.Sc.
Year: 1994
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of this study was to determine the functional
role of six prominent leg muscles during knee extension. Changes in
muscle-tendon
length and EMG activity were looked at in conjunction with the results
from an inverse dynamics analysis. The muscles investigated were the
monoarticular
vastus lateralis, soleus, gluteus maximus and the biarticular biceps
femoris,
rectus femoris and gastrocnernius. Four female and five male elite
rowers
performed on a QJessing rowing ergometer while kinematic information
was
recorded on cinefilm. The force applied to the stretcher, the force
applied
to the oar handle and the EMG activity were sampled simultaneously.
Through
inverse dynamics, net moments of force at the ankle, knee and hip
joints
and powers from these moments were computed for one drive.
The results showed a difference in the use of knee
extensors by female and male rowers. For the females, the power
produced
originated exclusively from the hip extensors. This contrasts with the
results obtained from the male subjects where power was produced by hip
and knee extensors. Plausible explanations include differences in
anatomical
structures between both sexes (skeletal dimensions, tendon attachments
location, muscle mass distribution), differences in rowing technique
and
deficiency in the knee extensor strength.
Paradoxical activity appeared to take place in the
recruitment of the biarticular gastrocnernius and biceps femoris during
the extension of the knee. More intriguing was the detection of
paradoxical
activity from the action of m. rectus femoris at the hip which it
seemed
to extend.
Net shoulder joint moment and
muscular
activity during light weight handling at different heights and
frequencies.
Author: Benoît Giroux
Degree: M.Sc.
Year: 1990
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of this study was to calculate net shoulder
(gleno-humeral)
joint moments from inverse dynamics and to measure muscular activity
from
six (6) shoulder muscles (supraspinatus, infraspinatus, middle deltoid,
anterior deltoid, trapezius. and pectoralis major) during light weight
handling at two (2) different heights (horizontal and vertical
displacements)
and frequencies (40 and 60 cycles/min), to simulate an occupational
cervicobrachial
working task (light weight displacement). Ten (10) normal adult male
subjects
were asked to move a known weight, representing 15% of the ma2dmal
lifted
weight, in both horizontal and vertical conditions at frequencies of 40
cycles/min and 60 cycles/min. Raw EMG signals from six (6) shoulder
muscles
were recorded and synchronized with the cinematographic data during
three
(3) trials of six (6) seconds each. The raw EMG signals of each muscle
were full wave rectified and filtered at three (3) Hz. The LE EMG
signals
were normalized by time (% cycle) and by amplitude (% MVC, and for the
analysis of variance, the normalized LE EMG signals were integrated (IN
LE EMG). The average shoulder angular velocities. joint moments and
moment
powers were computed from cinernatographical data. No significant
difference
were observed between both tasks for the supraspinatus, infraspinatus,
and pectoralis major IN LE EMG data as well as for integrated
normalized
shoulder joint moment for the whole cycle of movement. IN LE EMG data
from
middle deltoid, anterior deltoid, and trapezius muscles were
significantly
higher (p < 0.05) when performing the vertical displacement task for
the whole cycle of movement. This muscular activity difference between
vertical and horizontal tasks indicated that the vertical displacement
conditions induced higher muscular loads on the shoulder than the
horizontal
weight displacement conditions, although the vertical displacements
were
approximately 15% longer than the horizontal displacements. The
nonsignificant
difference of IN LE EMG between frequencies obtained for all muscles
indicated
that neither frequencies induced more muscular activity.
Internal work measurement and
simultaneous
oxygen consumption of impaired and normal walking
Author: Sylvain Grenier
Degree: M.A.
Year: 1998
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: This study evaluated the ability of two different methods
of measuring mechanical work, absolute power (AP) and absolute work
(AW),
to distinguish between normal and impaired gait. The relation between
these
two measures was examined as well as their relation to oxygen
consumption.
Global work measures from all three were compared and, in the case of
the
absolute power method individual joint power curves of the ankle, knee
and hip, for normal and two impaired conditions were examined. Four
subjects
of each gender were filmed for one full gait cycle, by three video
cameras,
over two AMTI force platforms, under three conditions; normal, locked
knee
and locked ankle. Oxygen consumption was measured with a TEEM 100 unit
carried by the subject in a "fanny" pack. Five normal gait trials and
one
trial of each impaired condition were analysed. The five normal gait
trials
yielded a normal mean plus or minus a 95% confidence interval. If any
of
the two condition's trials fell outside of this interval it was
considered
significantly different. A binomial test considered the probability
that
the number of differences across subjects was due to chance. For the
absolute
power method the ankle was different three of eight times (P=0.0058),
and
the knee two of eight (P=0.057). The absolute work method found
differences
one of eight times for each condition, neither was significant. A
repeated
measures ANOVA revealed no differences due to the extremely high
intersubject
variability. A Wilcoxon, matched pairs, signed ranks test found that
the
number of locked knee trials where the total work done as measured by
the
AP method were lower than the subjects' normal trials to be
significant.
Thus, locked knee walking required less energy than the normal gait
trials.
Efficiency was measured for both methods using both
internal and external work. The total work yielded the same pattern for
both methods. Locked knee walking was lowest (AP: 92.9%, AW: 57.03%)
while
the locked ankle walking was highest (AP: 115.4%, AW: 66.7%). The
normal
gait trials yielded a mean efficiency of 106.7% for AP and 59.26% for
AW.
Results over 100% for AP are due to an inherent overestimation of the
internal
work; corrections for this would reduce the value to approximately 70%.
The grand mean of the normal trials was closely
examined and found to match very closely with previous data (Winter
1983)
with respect to the ankle and knee joint power patterns. New patterns
at
the hip are put forth as being consistent and confirmative to expected
muscle recruitment during normal gait. The power bursts were present in
the normal grand mean curve of the hip: H1, a concentric extensor
moment
pushed the centre of mass forward, H2, an eccentric flexor moment
absorbed
a dip in the centre of mass and H3, a concentric flexor moment swung
the
leg forward. The research showed that the absolute work method could
not
detect impaired gait from normal while the absolute power method could.
Cortico-Motor adaptations and
proprioceptive
acuity in patients with unilateral anterior cruciate ligament deficiency
Author: Martin Héroux
Degree: M.A.
Year: 2003
Supervisor: François Tremblay
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Persistent weakness and reduced proprioception are the most
common impairments seen in individuals having sustained an anterior
cruciate
ligament (ACL) injury (Friden et al., 1999; Snyder-Mackler et al.,
1995).
In the context of this thesis project, we have attempted to get further
insights as to the nature of the proprioceptive deficits affecting
individuals
with ACL injuries and possible adaptations at the cortico-motor level
resulting
from unilateral knee dysfunction. Ten participants with chronic ACL
injuries
(age: 27.1±8.2) and eight healthy controls (age:
22.6±2.8)
were recruited for the study. The Knee Outcome Survey-Activities of
Daily
Living Scale (KOS-ADLS) was used to assess subjective knee function and
quadriceps strength was measured on a KIN-COM dynamometer during
isometric
maximum voluntary contractions (MVC; 3 trials, 2-3 s each). In the
first
experiment, proprioceptive acuity for force signals was assessed by
asking
participants to discriminate small differences in weight according to a
two-alternative forced choice procedure. The mass of the standard
weight
(3 kg) was increased by adding metal weights in successive blocks of
trials
(n=14) in a sequence of increasing difficulty (i.e., 0.50 kg, 0.28 kg,
O.20 kg and 0.09 kg increment). In a second experiment, transcranial
magnetic
stimulation (TMS) was used to estimate the cortico-motor excitability
of
the quadriceps motor representation. Magnetic stimulation was
administered
over the primary motor cortex and motor evoked potentials (MEPs) were
recorded
with EMG electrodes. Four indices of cortico-motor excitability were
derived:
resting motor thresholds (RMT), input-out (I-O) curves, MEP
facilitation
and silent period (SP) duration during voluntary contraction. The
H-reflex
was also measured to estimate spinal excitability. Comparison of
discrimination
thresholds determined in the first experiment revealed a significant
difference
(t=3.51, p<0.001) between the two legs in the ACL group; the injured
leg being significantly poorer at discriminating weights (mean
threshold,
199.9±68.3 g) than the uninjured leg (mean 144.1±33.9 g).
No such difference was noted in the control group (right leg,
161.2±42.6
g; left leg, 171.6±40.2; t=0.74, p=0.48). On the injured side in
the ACL group, no correlation was found between proprioceptive acuity
and
subjective scores of knee functions (r2=0.10), although a tendency was
observed for proprioceptive acuity to be better for those with lower
quadriceps
muscle strength as opposed to those with greater quadriceps strength
(r2=0.18).
In the second experiment, comparison between the two hemispheres
indicated
that RMT to magnetic stimulation were significantly lower in the
contra-hemisphere
controlling the injured leg (mean 54.5 ± 12.1 %, vs. mean, 58.5
± 14.5%, t=2.87, p=0.019). In contrast, RMT measured in the
control
group were comparable between hemispheres. Besides this difference in
RMT,
no other significant difference was detected for the other
cortico-motor
indices (i.e., I-O curve slope values, facilitated MEP amplitude and SP
duration). As expected, quadriceps H-reflex amplitude was found to be
smaller
on the injured side for those individuals with elicitable quadriceps
H-reflex
(n=5). Interestingly, the extent of the quadriceps motor
representation,
as reflected in the steepness of the I-O curve, correlated strongly
(r2=0.71)
with the amount of torque produced during quadriceps MVC. No other
correlations
could be established between the remaining indices of excitability and
measures of knee dysfunction (i.e., subjective function ratings,
quadriceps
muscle strength) Altogether, these results provide important new
insights
as to the nature of proprioceptive deficits in ACL injury and how the
neuromuscular
system adapts to unilateral chronic knee dysfunction. The reduced
ability
to discriminate weight on the injured leg likely reflects an impaired
capacity
to process force signals at the central level, whilst the increase in
cortico-motor
excitability detected on the hemisphere contra-lateral to the injured
leg
might be interpreted as a adaptation to poor mechanical stability of
the
injured knee by substituting greater voluntary control over more
automatic
reflex-driven muscle activity. Further research with large sample sizes
is needed to further examine these issues.
Calculation of the residual error
in
three-dimensional videography using stationary, panning and mobile
video
capturing techniques.
Author: Marshall Kendall
Degree: M.A.
Year: 2003
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Abstract: Significant technological advancements have been
made
in the study of human motion over the past few decades. There are
three known video capturing techniques for collecting three-dimensional
kinematic data; stationary, panning and mobile camera set-ups.
The
panning and mobile camera techniques allow for the cameras to follow a
subject throughout the entire length of the skill while maintaining a
close-range
view of the subject, something the stationary camera set-up does not
allow.
Accuracy of the panning and mobile camera techniques has not yet been
well
documented. The main objective of this study is to determine RMS errors
of three-dimensional coordinates in a 5.5-meter filming volume using
stationary,
panning and mobile camera techniques using three specific testing
conditions.
Three testing conditions were set-up in order to verify the
three-camera
systems (stationary, panning and mobile) ability to collect accurate
data
over a 5.5 meter field. The first testing condition involved the
simple linear movement of a calibration frame with reflective markers
(n=7).
The second test condition involved angular movement using a pendulum,
where
three vectors were precisely measured from three markers placed on the
pendulum and recorded by the three camera set-ups. The final test
condition
involved standard gait data collection. Reflective markers (n=9)
on the subject were positioned in a fashion to create triads on each of
the three segments on the right leg (thigh, shank and foot).
Three
segment lengths were precisely measured from the marker set on each
segment
for a total of nine segment lengths. All marker positions were
tracked
and reconstructed using the APAS system. Residual errors were
calculated
for the collected three-dimensional positions and vector lengths were
compared
to the reference measurements made with the micro scribe or
anthropometry.
Although the three camera techniques showed acceptable residual errors
throughout the three testing conditions, the mobile technique produced
the lowest RMS error for two out of the three test condition. For
the panning and mobile camera set-ups, camera-to subject distance is
much
smaller than the static camera technique for a 5.5-meter field.
Lamontagne
et al reported that residual errors could be minimized when
camera-to-subject
distance is reduced. The mobile technique produced acceptable
accuracy
in video analysis (Lafontaine et al., 2000). This technique did
reduce
the residual errors, of positional coordinates of markers and the
vectors
length measurements; by 55% and 44% in the gait testing condition
respectively
from errors obtained using the stationary camera technique. This
study allowed for a comparison of three video capturing techniques
abilities
to collect accurate data over a large filming area. The results
show
that, although all three camera set-ups produce low residual errors,
the
mobile camera set-up offers the best accuracy while maintaining a small
camera-to-subject distance, allowing for close range studies to be
performed
successfully.
Muscle activation
patterns during gait initiation.
Author: Natasha Flemming Kyle
Degree: M.Sc.
Year: 2006
Supervisor: Gordon Robertson
Department: School of Human Kinetics
Institution: University of Ottawa 
To
index
Abstract: Gait initiation is
a temporary movement between upright posture and steady-state gait. The
activation of several postural muscles has been identified to precede
changes
observed in vertical reaction force. Previous research examining gait
initiation has concentrated on the electromyographic activity of
muscles of the
lower limbs. Few studies, however, have looked at recruitment patterns
of the
muscles of the thigh and trunk. This study was conducted to determine
the
recruitment patterns and the roles of certain muscles of the trail and
lead
lower limbs and trunk for the duration from quiet stance to trail leg
toe-off.
Eleven healthy participants initiated gait with their right leg.
Electromyographic data were collected bilaterally from the erector
spinae,
tensor fasciae latae, adductor magnus and tibialis anterior muscles. In
addition, force platform data were recorded for the duration of quiet
stance to
toe-off of the trail limb. For each subject, onsets and offset timings
of all
eight muscles were calculated from time-normalized, ensemble-averaged
data. The
patterns of muscle activity across subjects were generally consistent.
The
earliest activation was consistently found to be the lead limb tibialis
anterior, followed by the lead limb tensor fasciae latae. The trail
limb
tibialis anterior was the next muscle to become active, which was
followed by
the trail limb tensor fasciae latae and then the trail limb adductor
magnus.
There was a tendency for the muscle activity to be more variable during
the
middle of the gait initiation process. There were notable
inconsistencies
between subjects for the order of the fifth and sixth muscle
activations.
Specifically, it was unclear as to whether the activation of the trail
limb
adductor magnus preceded the lead limb adductor magnus. The last two
muscles to
become active were consistently found to be the erector spinae of the
trail
limb side followed by the erector spinae of the lead limb side.
Title.
Author: Dany Lafontaine
Degree: Ph.D.
Year: 2005
Supervisor: Mario Lamontagne
Department: Anatomy and Neurobiology
Institution: University of Ottawa
To
index
Abstract:
Masticatory muscle activities in
temporomandibular
joint internal derangement.
Author: Chantal M. Lafrenière
Degree: M.Sc.
Year: 1995
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Intramuscular EMG of the lateral pterygoid muscles, surface
EMG of the temporalis and masseter muscles, electrogoniometry and force
measurements of the TMJ were synchronously used to investigate the
biomechanical
role of the two portions of the lateral pterygoid muscle in relation to
internal derangement (ID) of the temporomandibular joint (TMJ). This
study
dealt with the EMG analysis of five static conditions: resting,
resisted
protraction, maximum voluntary contraction (MVQ in opening, in molar
and
incisor clenching of TMJ ID and control subjects. Three maximum
isometric
masticatory forces were also recorded during the MVC in opening, molar
clenching and incisor clenching to compare forces and muscular activity
between the two groups. The analysis of variance results of the
integrated
linear envelop (LE) EMG showed no significant differences between the
two
groups. Therefore, there is no apparent reason to believe that the
temporalis
and masseter muscles are hyperactive in TMJ ID. The integrated LE EMG
of
the SLP was significantly lower in the TMJ group during molar clenching
(104 uV +/-60.0 over 159 uV +/-68.8 for a p=0.020). The SLP seemed to
have
lost its discal stabilizing function during clenching. The integrated
LE
EMG signals of the ILP were significantly higher in the TMJ ID group
during
rest, resisted protraction and incisor clenching (p=0.029, p=0.046,
p=0.031,
respectively). The ILP muscle has probably adapted to control the inner
joint instability while continuing its own actions. The ILP muscle
seemed
to have lost its functional specificity. The results of the isometric
forces
showed that TMJ ID subjects exhibited significantly lower molar bite
forces
(297.1 N over 419 N, p=0.042) confirming that they have less muscle
strength
and tissue tolerance than subjects with healthy masticatory muscle
system.
Incisor bite forces, however, showed a tendency to be higher in the TMJ
ID group (233 N over 180.5 N, p=0.168), possibly resulting from the
training
of a protracted bite and/or hyperactivity of the ILP associated with
ID.
Therefore an neuromuscular adaptation could be occurring in TMJ ID
masticatory
system affecting muscular actions and forces.
Computer simulation of planar
airborne
human motions. Masticatory muscle activities in temporomandibular joint
internal derangement.
Author: Edward D. Lemaire
Degree: M.Sc.
Year: 1988
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The airborne phases of a standing broad jump, dive front
roll, front somersault, layout dive, reverse 2.5 pike dive, front 3.5
tuck
dive, and long jump were used as the target skills for validation of a
computer simulation model. These events were filmed in either a
laboratory
or competitive setting to determine the take-off velocities, takeoff
angles,
total body angular momenta, relative angle histories, initial body
positions,
and segment lengths (for competitive situations) of the subjects. The
segment
lengths (10 segments) for the laboratory trials and the total body
weights
were determined by direct measurement. The absolute positions of the
segments
were predicted by the simulation model and compared to the original
motion
(obtained from film) on the basis of trunk angle and trajectory.
All but one of the simulated activities were found
to be valid for rotation (under 10% error). The long jump, which did
not
meet the validation criteria, exceeded the validation zone by only 1%.
For translation all but the 2.5 and 3.5 dives were valid (under 10%
error)
but it was shown that error in the criterion center of gravity values
were
likely the source of failure for these skills. It is expected that this
simulation will be of use for research, education, and training of
planar
airborne human movements.
Biomechanical analysis of
ankle injuries in
snowboarding.
Author: Sébastien Delorme
Degree: Ph.D.
Year: 1994
Supervisor: Mario Lamontagne and S. Tavoularis
Department: Mechanical Engineering
Institution: University of Ottawa
To
index
Abstract:
Kinematic and electromyographic
analysis
of wheelchair propulsion for various seating positions.
Author: Louise Mâsse
Degree: M.Sc.
Year: 1989
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The pattern of propulsion for five male paraplegics was
investigated
for six seating positions, consisting of a combination of three
horizontal
rear wheel positions at two seating heights. To simulate wheelchair
propulsion
in the laboratory, the wheelchair was mounted on high rotational
inertia
rollers. For three trials at each seating position, the subject
propelled
the designed wheelchair at 600/6 of their maximal speed which was
determined
at the beginning of the test session. At each trial, the subject's
propulsion
technique was filmed at 50 Hz with a high speed camera for one cycle
and
the raw electromyographic (EMG) signal of the biceps brachii, triceps
brachii,
pectoralis major, deltoid anterior, and deltoid posterior muscles were
simultaneously recorded for three consecutive cycles. The digitized
film
data were used to compute the linear and angular kinematics of the
upper
body, while the EMG signals were processed to yield the linear envelope
(LE EMG) and the integrated EMG (IEMG) of each muscle. The kinematic
analysis
revealed that the joint motions of the upper limbs were smoother for
the
low positions since they reached extension in a sequence (wrist,
shoulder,
and elbow) when compared to the high positions. Also, the peak linear
acceleration
of the hand at the end of the recovery phase was lower. thus
facilitating
the contact of the hands on the pushrims at the point of grabbing since
lower acceleration would reduce slippage of the hands on the pushrims.
Also, the forearm linear velocity slopes and the elbow angular velocity
slopes were less abrupt for the Backward-Low position. It was observed
that in lowering the seat position less IEMG was recorded and the
degrees
of contact were lengthened. Among the seat positions evaluated the
Backward-Low
position had the lowest overall IEMG and the Middle-Low position had
the
lowest pushing frequency. It was found that a change in seat position
caused
more variation in the IEMG for the triceps brachfi, pectoralis major,
and
deltoid posterior. The trunk angular momentum was not found to be
affected
by a change in seat position which may be related to the variability
among
the subject's technique of propulsion or a posture compensation.
Kinematic and electromyographic
analysis
of wheelchair propulsion for various seating positions.
Author: Jennifer McGregor
Degree: M.A.
Year: 1999
Supervisor: Heidi Sveistrup
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Very little is known of the development of the feedforward
postural
control mechanism. The purpose of this study was to identify
differences
in this system between two different stages of development. Two groups
of ten children, aged 4- and 5- years old and 10- and 11-years-old took
part in this study. Electromyographic (EMG) data from the right
anterior
deltoid, right and left erector spinae, right and left hamstring
muscles
and vertical ground reaction force data from the left and right foot as
well as the total body were collected during unilateral rapid forward
arm
movement about the shoulder in the sagittal plane. EMG and force data
were
examined for activity 100 ms prior to onset and 70 ms post movement
onset.
Onset latencies, probability of recruitment and recruitment order were
determined for all postural muscles. Onset latencies of changes in the
vertical ground reaction forces as well as coefficients of variation
were
determined for the vertical ground reaction forces. In general, the
younger
children demonstrated a similar postural muscle recruitment order as
the
older children. However, the younger children had a larger proportion
of
the postural muscles being activated before the movement onset than the
older children did. The probability of the younger children recruiting
the left erector spinae muscle was significantly less than that of the
older children. The younger children demonstrated greater intra-subject
variability about the vertical ground reaction forces than did the
older
children. These data suggest that with development, the feedforward
postural
used in preparation for a unilateral rapid arm raise becomes
increasingly
consistent. A shift in the feedforward postural adjustment goal from
safety
to efficiency is proposed.
Measurement and statistical
analysis
of the passive vsicoelastic properties of the human knee joint during
flexion
and extension motion.
Author: Steven R. McFaull
Degree: M.Sc.
Year: 1993
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of the present investigation was to determine the
net passive elastic joint moment and the angular damping coefficient of
the human knee joint in full range flexion- extension. A secondary
purpose
was to develop regression equations to predict the measured passive
properties
from anthropometric data. Seventeen male subjects (22-31 years)
participated
in the study. The passive elastic moments were determined using a
specially
constructed apparatus: a horizontal knee arthrograph (HKA). The
subject's
leg was rotated through the full range of voluntary motion and forced
slowly
into the extremes of flexion and extension. Transducers mounted on the
HKA measured the resistive moment as a function of the knee angle. The
damping coefficient was determined using the small oscillation
technique.
This technique is a linearization method that allows determination of
the
angular damping coefficient as a function of knee angle through a
simple
analysis of the underdamped response curve. The viscous moments may be
obtained by multiplying the damping coefficient by the angular velocity
(in rad/s). Measurements were made at 10 , 45 , 90 , 110 and
130
of flexion (0 is full extension). All measurements were made with
the subject's muscles in the passive state. This state was ensured by
monitoring
the surface EMG activity of five major muscles crossing the knee joint.
The hip joint was fixed at 90 and the ankle was set at 0
(neutral).
The passive elastic moments increased exponentially as the limits of
either
flexion or extension were approached. The midrange of joint motion was
a low moment (< 5 N.m), low stiffness region. Considerable
variability
in the magnitudes of the passive elastic moments existed across
subjects.
At 140 of flexion, between about 5 N.m and 86 N.m was measured
while
the range at full extension (0 ) was about 6 N.m to 22 N.m. The angular
damping coefficient was a nonlinear function (approximately quadratic)
of the knee joint angle. The variability was not quite as high compared
to the elastic component. Robust multiple linear regression techniques
showed that, depending on the knee angle, between 50% and 98% of the
variation
in the passive elastic moments could be accounted for by up to three
anthropometric
parameters. For the damping coefficients, the range was slightly lower:
43% to 96%. Application of the data to the late swing phase of walking
indicated that, for some subjects, the passive moments may contribute
(or
oppose) significantly to the net joint moment. In conclusion, it
appears
that the resistance offered by. the passive tissues spanning the knee
joint
varies considerably across subjects (in the age range of 22-31 years).
Researchers may consider including such sources in their biomechanical
models to enhance their fidelity.
Contribution
de l’information tactile
à la stabilité posturale chez la population
âgée.
Author: Annie-Claude Mireault
Degree: M.A.
Year: 2003
Supervisor: François Tremblay
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Résumé: Le toucher léger contribue de façon
active à diminuer les oscillations corporelles, lorsqu’un sujet
touche légèrement une surface stable, même lorsque
les forces de contact appliquées par la pulpe du doigt sont
inadéquates
pour stabiliser mécaniquement le corps (Clapp et Wing, 1999;
Jeka
et Lackner, 1994). Le but de cette étude était de
comparer
l’habileté des jeunes adultes et des personnes
âgées
à faire l’utilisation du toucher léger en station debout
normale. Nous avons testé 25 jeunes sujets (âge : 19-32
ans)
et 35 personnes âgées (âge : 60-86 ans). Nous avons
d’abord évalué la perception tactile au niveau de la
pulpe
de l’index des sujets à l’aide d’un test de détection de
pressions minimales ainsi qu’à l’aide d’un test de
détection
d’espacements. Nous avons aussi évalué la
stabilité
posturale des sujets. Ceux-ci devaient se tenir debout sur des
plates-formes
de force de type AMTI dans diverses conditions sensorielles. Les essais
expérimentaux (durée 60 sec.) comportaient deux
conditions
visuelles (yeux ouverts : EO ou yeux fermés : EC), trois
conditions
de toucher léger avec la pulpe de l’index (pas de toucher : NT,
toucher d’une texture lisse : ST, toucher d’une texture rugueuse: RT)
et
deux conditions de support (surface stable ou surface instable). Les
résultats
ont démontré que le toucher léger avait
contribué
à atténuer significativement les oscillations du centre
de
pression plantaire (CPP-RMS) dans la direction
antéro-postérieure
(~ 30-40% de réduction) chez les jeunes sujets et chez les
personnes
âgées pour toutes les conditions sensorielles
testées
(vision, surface). Les oscillations du CPP en ML ont été
moins affectées par le toucher léger pour les conditions
sensorielles testées (vision, surface). Cependant, les personnes
âgées ont bénéficié du toucher
léger
pour la stabilisation posturale en ML lors de la station debout sur la
surface instable (réduction: ? 20% du CPP). Pour atteindre le
niveau
de stabilisation observé chez les jeunes, les sujets
âgés
ont toutefois déployé des forces de contact
significativement
plus élevées. Les sujets jeunes ont appliqué en
moyenne
des forces de contact de 0.32±0.15 N sur la plaque tactile,
alors
que les sujets âgés ont appliqué en moyenne des
forces
de contact de l’ordre de 1.2±0.68 N. Chez tous les sujets jeunes
(100%) et la vaste majorité des sujets âgés (75%),
les forces de contact appliquées étaient en
deçà
des forces requises pour produire une stabilisation physique (4-8 N).
Dans
les tests psychophysiques, les personnes âgées ont obtenu
en moyenne des seuils de détection de pressions minimales 5 fois
plus élevés que ceux obtenus chez les sujets jeunes
(Agés:
245±233 mg vs Jeunes: 522±41 mg). Les sujets
âgés
ont aussi obtenu en moyenne des seuils d’acuité spatiale 3 fois
plus élevés que ceux enregistrés chez les jeunes
sujets
(Agés: 2.60±1.44 mm vs Jeunes : 0.88±0.35 mm). Les
corrélations entre les seuils d’acuité spatiale et les
forces
verticales enregistrées (Fz) pendant les essais avec contact se
sont révélées très significatives (r de
0.37
à 0.47). Les valeurs des seuils d’acuité spatiale obtenus
au test de la détection d’espacements constituaient donc de bons
indicateurs des forces verticales (Fz) utilisées pour la
stabilisation
posturale. L’utilisation de forces de contact plus
élevées,
mais non excessives chez la majorité des aînés
(75%),
est interprétée comme une stratégie visant
à
optimiser les signaux sensoriels provenant du membre supérieur
pour
ainsi atteindre une stabilisation posturale adéquate. Pour la
minorité
des aînés (~25%) présentant une
détérioration
plus importante de l’acuité tactile, il semble que la
stratégie
de support physique soit l’unique choix possible.
Mathematical model of the sprint
relay
race.
Author: Stephen D. Murphy
Degree: M.Sc.
Year: 1992
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of this investigation was to develop and validate
mathematical models of the sprint relay race. Two approaches, a
classical
exponential approach and a C4new" polynomial approach, were chosen for
implementation. Archival film of a 100 in sprint was used to gather
displacement
data for the first 60 m of the race. Filming had been performed with a
single highspeed 16 mm cine camera (LOCAM) at 50 fps. The coordinates
were
digitized, scaled and filtered using a low pass, critically damped, 4th
order, zero-lag Butterworth digital filter with a I Hz cutoff
frequency.
Linear velocities were calculated using finite differences.
A sprinter was modelled in two ways. The first was
an Exponential Model which required as input a personal best time for
the
100 in race and the sprinter's maximum constant velocity. The second
was
a Polynomial Model which required as input the parameters mentioned in
the Exponential Model and, additionally, the displacement coefficients
for the first 60 m of the 100 in sprint. Relay software was developed
to
piece the sprint relay together using the corresponding exponential or
polynomial approach.
The results indicated that the relay software
reasonably
simulated the kinematic and temporal quantities of a 4xlOO m relay and
can be used by coaches to gain insight into the sprint relay without
risking
injury to their athletes. Furthermore, the Exponential Model, using
less
information, described the sprinter's kinematics better than the
Polynomial
Model.
Title.
Author: Kasey Parker
Degree: M.A.
Year: 2006
Supervisor: Yves Lajoie
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract:
Biomechanical
comparison of stair and ramp descent.
Author: Andrew Post
Degree: M.Sc.
Year: 2006
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Despite many studies of human gait, a
lack of knowledge
exists concerning the joint kinetics of the lower extremity during
stair and
ramp descent. The purpose of this project was to compare and contrast
the
moments of force and moment powers at the hip, knee and ankle joints
during
stair and ramp descent at self-selected pace.
A sample population of five male
and five female volunteers descended five times down a 10-degree ramp
at normal
gait speed, followed by five stair descent trials. Force platforms
mounted on
the ramp and stairs measured ground reaction forces while a video
camera
collected the sagittal view trajectories of markers placed on the left
side of
the body. Inverse dynamics computed the moments and powers at each
joint. These
data were then normalized to body mass and stride time and ensemble
averaged.
Stair descent has a larger
eccentric plantar flexor peak at the ankle joint during weight
acceptance. The
knee exhibits slightly larger eccentric knee extensor peaks during ramp
descent
at push-off and there was higher loading of the hip during ramp descent
as
compared with stair descent. The higher ankle powers at FS during stair
descent
reveal a concern for those people suffering from ankle pathology and
the larger
hip and knee peaks during ramp descent is of concern to those with hip
and knee
problems.
Toddler gait: Comparison of
toddler and
adult joint kinetics of gait.
Author: Stefan Potoczny
Degree: M.A.
Year: 2003
Supervisor: Heidi Sveistrup and D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Behind every purposeful movement lies a pattern of control
and
activation. One of the most fundamental movement patterns for humans is
that of walking or gait. This study was conducted to further understand
gait development of toddlers. This developmental stage was investigated
with 13 healthy normal toddlers (11 girls and 2 boys) between the ages
of 10 and 24 months who were autonomous walkers of less than a year.
All
toddlers walked across two force plates (AMTI) touching only with the
right
foot and were filmed with three (Panasonic) video cameras. Support
moments
as well as hip, knee and ankle joint moments and powers were calculated
for between 6 and 14 steps per toddler. Joint moments and powers were
normalized
to percent of stride and body mass and were examined across subjects to
observe developmental changes over the first year of walking. As well,
the toddler joint moments and powers were compared to that of adult
slow
walking reported by Winter ( 1991) .The data suggests two things: 1)
toddler
joint moments and joint powers develop over the first year of walking
in
a distal to proximal fashion and 2) toddler support moments, joint
moments
and joint powers are different from that of adults.
Comparison of methods for
calculating
internal work of elite running.
Author: Sheila B.A. Purkiss
Degree: M.Sc.
Year: 1996
Department: School of Human Kinetics
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: There are two basic models that are used to calculate the
internal work involved in movement. The first, an energy-based model,
calculates
the changes in the energy of the segments. There are many variations of
this model but Aleshinsky (1986) has shown that this approach lacks
mathematical
validity. The other, a power-based model, integrates the joint powers
to
find work. A modified power model (using absolute values) was shown by
Aleshinsky (1986) to be mathematically valid but has only been used in
two studies (Chapman et al., 1987; Caldwell and Forrester, 1992) each
having
only one subject. A version of this model was used in this study and
was
termed the absolute power method. For comparison purposes a modified
version
of the energy approach, called the absolute work method, was used. The
internal work was then normalized for body mass and running velocity to
obtain the "internal biomechanical cost" (IBC). The IBCs of normal
running
for four elite male and four elite female runners were compared to
their
IBCs of four inefficient running styles.
The absolute power method was able to detect that
the inefficient runs produced significantly higher internal work than
normal
running in 30 out of 32 cases (94%). Absolute work (the energy
approach)
could detect the inefficient runs in only 15 out of 32 cases (46%). As
well, the absolute work approach was shown to be more variable and less
reliable than the absolute power approach. The absolute power method
also
proved to be a useful tool for examining the work performed at each
joint
during a movement, thereby providing insight into where significant
inefficiencies
occur.
Effectiveness of the Kinetic
Wedge foot
orthoses modification to improve gait posture.
Author: Kerry K. Rambarran
Degree: M.A.
Year: 2003
Supervisor: Edward D. Lemaire and D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Clinically, Functional Hallux Limitus (FHL) has been
identified
as a contributor to the disruption of proper progression of the
inverted
pendulum through the sagittal plane. The Kinetic Wedge Custom
Foot
Orthotic (CFO) modification has been used by the podiatric community to
facilitate proper first metatarsal-phalangeal (MTP) joint function and
improve gait posture. The aim of this study was to determine the
effectiveness of the Kinetic Wedge custom foot orthosis (CFO)
modification
to improve gait, posture, centre of force velocity, plantar pressures
of
the foot, and perceived pain. Fifteen healthy subjects (9 women,
6 men) 22 to 53 years of age diagnosed with moderate to severe FHL
volunteered
for the study. Kinematic and plantar pressure date were collected
without Kinetic Wedge (NKW) and with Kinetic Wedge (KW). After
statistical
analysis, it was determined that there was a significant reduction of
plantar
pressure under the first MTP (p<0.05), however, there were no
significant
changes in plantar pressures under the allux and fifth metatarsal
(p>0.05).
There was no significant change in centre of force velocities
(p>0.05).
In addition, there were no significant changes in trunk, hip, knee, and
ankle kinematics (p>0.05). Furthermore, self perceived pain did not
significantly
reduce 2 months afer testing (p>0.05). Since subjects were
tested
using the modified CFOs after 30 minutes of practice, it was determined
that additional practice time may be necessary to better determine the
efficacy of the modified CFOs.
An In vivo three-dimensional kinematic
analysis
of the anterior cruciate deficient knee.
Author: Dan K. Ramsey
Degree: M.A.
Year: 1999
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The aim of this investigation was to determine whether
application
of a functional brace reduced rotational and linear tibial
displacements
during the performance of a One Legged Hop. Steinmann traction pins
were
surgically implanted into the femur and tibia of six young normal
healthy
subjects having either a partial or complete anterior cruciate ligament
(ACL) rupture. Stereophotogrammetric radiographs (RSA) were taken once
target markers were affixed to the pins. Angular and translation
measurements
were recorded using the MacReflex motion analysis system at 120 Hz
while
ground reaction forces via a Kistler force plate were synchronized to
collect
at 960 Hz. Patients were required to jump for distance to sufficiently
stress the ACL. Subjects were randomly assigned to start with either
the
braced or non-braced condition. Analysis focused on differences in
magnitudes
and changes in the shape of the curves between bracing conditions.
Intra-subject
peak vertical forces and anterior shear forces were generally
consistent
between non-supported and braced conditions; indicating hops onto the
force
platform were similar. The small intra-subject angular and
translational
differences cannot be attributed to variations in hopping styles, but
rather
to the brace itself. Magnitude's varied across subjects owing to the
fact
that subjects hopped within their own comfort limits. Tibiofemoral
rotations
and translations show a general trend across subjects, i.e. the shape
and
amplitudes of the skeletal marker based curves were similar. The major
difference is the systematic shift between the unbraced and braced
trials.
The offset between conditions can be attributed to the different
standing
reference trials used during the non-braced and braced trials. This
created
small differences in alignment of the tibial and fernoral anatomical
co-ordinate
systems rather than to application of the brace itself. Generally,
intra-subject
knee kinematics was very repeatable but differences between non-braced
and braced patterns were small. This may be due to the invasiveness of
the protocol, that landings were performed with a deficient limb, or
subjects
jumped within their own comfort limits which did not maximally stress
the
ACL. As expected, inter-subject differences were typically much larger
than intra-subject variability. Differences mainly consisted in
amplitudes
and position at touchdown.
Comparison of mechanical energy expenditure
and
mechanical
efficiency of normal walking at various velocities.
Author: Kevin M. Semeniuk
Degree: M.A.
Year: 2000
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The goal of this study was to assess the experimental
capability
of two different mechanical methods, the absolute power method (APM)
and
the absolute work method (AWM), in quantifying the mechanical energy
expenditure
(MEE) and the mechanical efficiency of walking over a selected range of
velocities. The APM used a kinetic-based approach to calculate MEE from
the net moments and forces occurring at each joint (MEEp). The AWM
utilized
kinematic data to derive MEE from the changes in segmental energy
(MEEw).
Ten healthy male and female subjects were required
to walk at five different velocities determined from their normal or
“natural”
walking speed; below 20% and 40%, normal and above 20% and 40%. Ground
reaction forces and two-dimensional video data from the sagittal plane
of motion were collected, with five trials at each condition analysed
to
determine MEE. Every subject also performed a single trials of
overground
walking at their required velocities to obtain the aerobic demand
necessary
to calculate mechanical efficiency.
It was shown that MEEp and MEEw were in fact similar
as determined by a repeated measures ANOVA. The correlation between the
two methods was quite strong as indicated by the coefficient of
determination
(0.824). However, MEEp significantly determined all individual walking
conditions except between the above 20% and 40% conditions, whereas
MEEw
results increased in variation with increasing velocity and failed to
specify
a difference between any walking condition. Furthermore, both
normalized
MEE results demonstrated curvilinear relationships with walking
velocity,
where the coefficient of determination was higher for MEEp (0.854) than
for MEEw (0.769). The overall mean of the joint moment and power curves
revealed a change in magnitude proportional to the change in velocity
while
the patterns remained similar to the normal condition, demonstrating
very
strong correlations.
Oxygen consumption increased curvilinearly with
walking velocity (r2=0.951). MEEp showed a greater relationship with
oxygen
consumption (r=0.910) than did MEEw (r=0.893). In the calculation of
mechanical
efficiency, a significant difference was determined between the APM and
AWM (P 0.05). Using MEEp provided efficiencies that were consistently
lower
and hence more realistic than MEEw. MEEw efficiencies were on average
14%,
17% and 28% greater in the normal, above 20% and above 40% conditions,
respectively. Furthermore, it was expected that the maximum mechanical
efficiency of each subject would occur during the normal walking
condition,
thus producing an inverted U-shaped curve. Individual results
demonstrated
a maximum efficiency during the intermediate conditions in 7 out of 10
subjects as calculated with MEE,. Maximum MEEw efficiency occurred in
the
above 40% condition in all ten subjects. Trend analysis revealed a
quadratic
trend in the overall mean normalized MEEp efficiencies and a linear
trend
in the MEEw efficiencies
Although the mechanical methods did not differ
significantly,
this research showed that the APM could provide a more accurate measure
of MEE to determine the changes made in walking velocity. MEEp also
proved
to be strongly related to the metabolic energy expenditure and was able
to produce values of mechanical efficiency which realistically
represented
the changes occurring in walking over five different velocities.
Functional knee brace migration:
Biomechanical and neuromuscular alterations.
Author: Jonathan Singer
Degree: M.A.
Year: 2005
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Functional
knee bracing has been shown to alter
lower limb joint mechanics, which may protect the anterior cruciate
ligament.
It is not known, however, the effects of brace alignment or brace type
on lower
limb joint mechanics. This study was conducted to determine whether the
use of
a functional knee brace, the type of brace used or its alignment
relative to
the knee causes biomechanical or neuromuscular alterations to gait. Ten
healthy
participants took part in all conditions: walking with a shell and soft
shell
brace, each aligned according to the manufacturers’ specifications;
walking
with each brace distally misaligned by 1 cm as well as walking without
a brace.
A motion analysis and force plate system was used to determine the
three-dimensional angular impulse, peak joint moments and peak joint
angles of
the ankle, knee and hip. Electromyographic data were used to support
the
kinetic data. All data were time normalized to one stride. In addition,
kinetic
data were normalized to body mass and kinematic data were normalized to
the
standing position. In comparison to unbraced walking, the shell brace
in its
aligned position significantly reduced the peak ankle plantarflexor
moment.
Additionally, there was a decreased peak knee flexion angle with the
aligned
shell and soft shell braces as well as an increased peak knee adduction
angle
and a reduced peak knee internal rotation angle with the aligned shell
brace.
Although there were alterations in lower limb mechanics during walking,
induced
primarily by the shell type functional brace, these changes were
neither of
great enough magnitude nor occur during a time period that would place
the ACL
under abnormal strain.
Influence of block angle and diver stance on
power
production
and takeoff velocity in swim starting.
Author: Vivian-Lee Stewart
Degree: M.Sc.
Year: 1996
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: This research examined three different diving stances during
the competitive grab start of swimming that of the standard position,
called
the Toes-Over position, the Toes-Back position where the swimmers were
not permitted to curl their toes over the edge of the -10 degree
inclined
starting block and the Level position where the platform was levelled.
A starting position was being sought which would increase a swimmer's
projection
angle from the blocks and thus flight time before entry. Eight female
swimmers
were filmed using a stationary cinecamera while reaction forces were
collected,
simultaneously, by a force platform mounted on the starting block. Net
forces and moments of force at the three leg joints were calculated
using
inverse dynamics (Winter, 1979). The powers produced by these net
moments
were then computed to determine which muscle groups contributed to the
work done during the start.
Based on the results of this study there were no
significant differences in the performances of female swimmers using
the
grab start technique in terms of takeoff velocity, takeoff angle or
horizontal
distance for the dive when starting from a level surface or -10 degree
inclined surface. The hip extensor muscles provided the greatest amount
of power during the propulsive (thrust) phase of the swim start.
Modelling the muscles of the
mower extremity:
The effect of varying joint angles on muscle length
Author: Taunya Allyson St. Pierre
Degree: M.Sc.
Year: 2002
Supervisor: D. Gordon E. Robertson
Department: Ottawa-Carleton Institute of Biology
Institution: University of Ottawa
To
index
Abstract: Polynomial regression was used to describe the relationship
between
lengths of the five muscles of interest and lower extremity joint
angle(s).
A difference between the genders was observed, so the male and female
data
were separated and five regression equations (one per muscle) were
fitted
to each data set.
In an attempt to build general regression equations normalization and
transformation of the data was performed, but these manipulations of
the
data did not lead to predictive equations. Addition of leg segment
length,
for the monoarticular muscles, and height, for the biarticular muscles,
as independent variables did significantly increase model fit.
The general regression model was quantitatively compared to the leg
segment lengths and the actual observed values. It was also
qualitatively
compared to two other models. Results showed that while the general
regression
model is good at predicting muscle function, it is not a very accurate
predictor of muscle length.
Mechanical behaviour of
hamstring muscles and hip
joint
in low-back pain and control subjects.
Author: Fary Taffazoli
Degree: M.Sc.
Year: 1994
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The purpose of this study was to measure and compare the
passive elastic moment, the stiffness and the damping coefficient of
the
hip joint, as functions of the hip and knee joint angles in men with
and
without low-back pain. Two conventional test, the Straight-Leg- Raising
test (SLR) and the Trunk Forward Flexion, were also performed and
compared
between these subjects. The passive elastic moment was measured using
an
isokinetic device (KinCom 500 H) in the passive mode. This device
raised
the lower limb from the horizontal position to the SLR angle at a slow
and constant angular velocity (5 deg/s). A custom made splint connected
with the lever arm of the isokinetic device maintained the knee in
extension
and the ankle in the neutral position. The damping coefficient of the
hip
joint was measured for 0, 15, 45, 60, 75 and 90% of SLR angle of each
subject,
using the suspension method based on small oscillation theory. To
ensure
that muscles were inactive during the passive hip moment tests, muscle
activity was monitored with surface EMG. The stiffness was computed as
the ratio of the change in passive elastic moment to the change in the
hip angle. The passive elastic moment, the stiffness and the normalized
trunk flexion were significantly different between the two groups (p
<
0.05, p < 0.01 and p < 0.05, respectively). There was however, no
difference between the two groups in the results of SLR and damping
coefficient
of the hip. The passive elastic moment was a nonlinear function of the
hip flexion angle and showed large intersubject differences, especially
as the joint limit was approached. The damping coefficient was a
polynomial
function of the hip flexion angle. The measured variables were analysed
using a discriminant function and it was shown that the two groups were
clearly discriminable in a meaningful manner.
Title.
Author: Daniel Théoret
Degree: M.A.
Year: 2005
Supervisor: Mario Lamontagne
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract:
Balance training using
virtual reality as compared
to
an activity-based exercise program for adults with traumatic brain
injury.
Author: Marianne Thornton
Degree: M.A.
Year: 2004
Supervisor: Heidi Sveistrup
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: Exercise has been considered important in the management of
functional
balance problems although there are limited data supporting
effectiveness
after traumatic brain injury (TBI). This thesis compared two functional
balance retraining programs: a virtual reality (VR) generated program
and
an activity-based (AB) program. Participants (n=33, age 18-66) had
sustained
a moderate or severe TBI (initial Glasgow Coma Scale [GCS] <12) 6
months
or more before the start of the study. Participants were quasi-randomly
assigned to either an intervention group or a control group that
received
no intervention. Groups were matched on initial Berg Balance Scale
scores
(BBS), years since TBI, and age. Static standing balance (using a force
plate), functional balance (using the Community Balance and Mobility
Scale
[CB&M]) and perceptions of balance and function (using the
Activity-specific
Balance Confidence Scale [ABC] and the Lower Extremity Functional Scale
[LEFS]) were measured at baseline, after six weeks of intervention, and
3 months later. BBS and CB&M scores improved for the exercise
groups
after six weeks. Some of the improvements were still present at three
months.
Functional balance improvements were supported by increased scores on
the
ABC, the LEFS, and by participant focus group comments. The focus
groups
also indicated the multidimensional benefits of both types of exercise.
While not statistically significant, the VR group reported higher
scores
of functional balance and mobility, balance confidence, and more
positive
comments from participants than the AB group. This supports the use of
VR as a potentially effective method of delivering exercise.
Contrast of methods for
calculating internal
work of running for trained and untrained runners.
Author: Patricia A. Turnbull
Degree: M.Sc.
Year: 1995
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: This research contrasted two methods for calculating the
internal work of running. The methods are known as absolute work (also
known as Winter's 1979) Wwb calculation) and absolute power. The study
also examined whether or not there were differences in the amounts of
internal
work done by trained and untrained runners. The absolute work approach
was believed to calculate internal work incorrectly. The absolute power
approach, on the other hand, correctly computes internal work by taking
the absolute power generated or absorbed at each joint and summing them
across a movement cycle.
Five trained and five untrained female runners were
filmed, while running across a laboratory runway, by a cinecamera at
100
fps. Simultaneously, force plate data, for one step, were collected.
The
results showed absolute work values were three times the absolute power
values. Furthermore, the results of the absolute work method were too
large
compared to the estimated physiological cost of running. Conversely,
the
absolute power method produced amounts of internal work that were too
high
but were much closer to the estimated physiological cost. There was no
significant difference between work values of the two groups of
runners,
for the absolute power method. The correlations for the absolute power
method were higher than those of the absolute work method. Based on the
results, the absolute power method provided a more accurate estimate of
locomotor cost of running.
Infant bouncing: Analysis of
skilled
and less-skilled behaviour.
Author: Lori Ann Vallis
Degree: M.A.
Year: 1998
Supervisor: Heidi Sveistrup
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: This study examined joint kinematics and muscle activation
patterns produced by infants of different bouncing skill levels as they
bounced in a Jolly Jumper harness system. The relationship between
three
components of bouncing was also determined. The three components were:
i) the oscillation pattern of the mass-spring system which can be
characterized
as a harmonic oscillator; ii) the baby's contribution to the bouncing
behaviour
which can be characterized in part as a forcing function and in part as
a harmonic oscillator; and iii) the combination of these two components
which corresponds to the output or the bouncing behaviour. Infants (N =
9) were instrumented with five surface electrodes over the lower leg
muscles
and dressed in black tights and a black long-sleeved body suit with
reflective
markers placed on the tights over seven body landmarks. Infants were
then
supported in a modified Jolly Jumper harness and encouraged to bounce.
Loading of the harness and spring was recorded using a load cell
attached
to the ceiling. Vertical ground reaction forces were recorded using two
force platforms mounted into the floor beneath the infant's feet.
Bouncing
behaviour was recorded for six 30-second trials. While bouncing, the
infants
were filmed with a video camera placed at ninety degrees to the
sagittal
plane. The infants were grouped as less-skilled, moderately-skilled and
skilled bouncers.
There was a general trend from a chaotic to an
organized
pattern of interjoint coordination as the level of bouncing skill
increased.
Infants in the moderately-skilled and skilled groups bounced at one of
two distinct frequencies, 1.5 or 2 times the resonant frequency of the
spring. Similarly, the baby contributions and kinematics of the lower
limbs
as reflected in qualitative analysis of phase-plane plot patterns were
distinctly different for the two frequencies of bouncing. The
phase-plane
patterns suggested that one group of infants used a spring-like control
mechanism for lower limb movement while the second group of infants
incorporated
a point-specific (focused, position-specific) control of forces into
the
mechanism for lower limb movement. This distinction was less apparent
in
the qualitative analysis of angle-angle plots. The qualitative dynamics
suggest that there are two predominant attractor states for the
production
of bouncing behaviour. This research expands the current literature of
infant behaviour and furthers our understanding of the qualitative
dynamics
of skilled and less-skilled bouncing.
Comparison of the 1991 NIOSH
lifting
equation and erector spinae muscle electromyography.
Author: Greg G. Weames
Degree: M.Sc.
Year: 1995
Supervisor: D. Gordon E. Robertson and J. Peter Stothart
Department: School of Human Kinetics
Institution: University of Ottawa
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index
Abstract: This study determined whether lifts rated as acceptable by
the 1991 NIOSH equation calculations elicited myoelectric amplitudes of
the erector spinae musculature (ES) within acceptable muscular load
limits
for continuous repetitive lifting tasks. Ten male subjects had surface
electrodes placed bilaterally along the spine at levels T9, L1 and L3,
4 cm, 9 cm and 3 cm lateral to the midline, respectively. Each subject
performed eight trials of five lifting conditions that were used to
examine
the horizontal factor (HF) and asymmetrical factor (AF) of the 1991
NIOSH
equation. All lifts were ordered randomly and initiated and terminated
in a standing position. The lifting motion was unconstrained and
incorporated
a "flatback", free-style lifting technique. EMG data were collected and
linear envelopes (LE) were ensemble averaged across subject trials for
each condition and normalized to a maximum voluntary contraction (MVC).
Subject LE EMGs were ensemble averaged to generate condition LE EMG
averages
and subsequently converted to amplitude probability distribution
functions
(APDF). Percent MVC values from the APDF curves were compared to
muscular
load limits. A three-way, repeated measures, mixed model analysis of
variance
determined significant main effects for conditions, electrode
placements
and probability levels of the APDFs. There was general agreement
between
the 1991 NIOSH equation and muscular load limits. Bilateral T9 ES often
exceeded "static" muscular loads and right L3 often exceeded "static"
and
"median" muscular loads. There was a significant (p < 0.01)
difference
for each main effect. The APDF EMG analysis was more sensitive to
differentiating
between conditions than the 1991 NIOSH equation. Phasic and amplitude
EMG
analysis of the ES for occupational lifting tasks could be best
represented
by the musculature at L3, 3 cm lateral to the midline.
Lower limb muscle function during
deep-knee
bending
Author: Jean-Marie John Wilson
Degree: M.Sc.
Year: 1989
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: To understand the functions of lower limb muscles during
simultaneous hip, knee, and ankle extension, electromyographic,
kinetic,
and muscle length data were collected from experienced subjects
performing
weighted and unweighted deep-knee bending movements. Functions of the
gluteus
maximus, biceps femoris, semitendinosus, rectus femoris, vastus
lateralis,
soleus, gastrocnernius and tibialis anterior muscles about their
associated
joint(s) was determined by means of a joint kinetic, EMG, and muscle
length
based muscle function classification system.
Analysis of the results indicated that the prime
movers of the deep-knee bending movement were the one-joint soleus,
vastus
lateralis, and gluteus maximus muscles. Although it has been believed
in
the past that co-contracting antagonistic two-joint muscles functioned
simultaneously as knee and hip extensors during the entire ascent phase
of the movement, the data presented in this study suggested that these
muscles acted mainly as stabilizers of the hip and knee. Despite the
fact
that lengthening of the rectus femoris, semitendinosus, biceps femoris,
and gastrocnernius muscles during periods of cocontraction revealed an
ability of these muscles to act as agonists about one joint, there
existed
no evidence supporting the paradoxical functioning of these muscles as
theorized by Lombard (1903) and Molbech (1965).
Locomotor adaptations to changes in
incline ascent gradient
Author: Robyn Melissa Wharf
Degree: M.A.
Year: 2005
Supervisor: D. Gordon E. Robertson
Department: School of Human Kinetics
Institution: University of Ottawa
To
index
Abstract: The
use of
inclined surfaces, that include
ramps, is a popular means for permitting access to a building’s
different
levels. Yet, studies investigating mobility on inclined surfaces have
dominantly addressed the functional interaction between incline
gradient, slip
coefficient, and the kinematics of gait, mainly for speed and cadence.
The
purpose of this investigation was to quantify the moments of force,
moment
powers and work done by the moments of force of the lower extremities
during
the ascent of inclines of various gradients as compared to those of
level gait.
Twelve participants (6 female, 6 male) age 24 + 1.93 years
participated
in the study. Sagittal plane kinematics from a 60 Hz digital video
camera and
ground reaction forces from a force plate embedded into the ramp were
collected. The participants’ ascended three different ramp conditions,
five
times each (3, 6, and 9 degrees) plus level walking. Results yielded
few
differences between the level and three-degree incline conditions,
however, as
the incline angle increased, concentric work by the ankle plantar
flexors
increased significantly at nine degrees by 78% compared to level while
negative
work decreased by 69%. Similarly, at steeper inclines, the knee
extensor moment
showed significant increases in concentric work after foot-strike with
a 290%
increase at nine degrees compared to level and significantly less
eccentric
work around toe-off by 43%. As for the hip flexors, there was increased
concentric work at push-off and early swing especially at both six and
nine
degrees as compared to level gait with 75% and 299% difference,
respectively.
These results agree with the Canadian Building Code regulations for
building
ramps that allow up to a three-degree incline to be indefinite length
but require
limitation for steeper angles.
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