Breeding success in the broiler chicken has been accompanied by gait problems which are detrimental to productivity and welfare. Although these gait issues have not been reported to the same extent in Pekin ducks, there is concern that such problems will manifest if the duck continues on its current selection trajectory. In order to understand how changes in morphology due to selection have affected gait in both species, divergent lines were objectively assessed for gait using a pressure platform (12 birds per line at three, five and seven weeks of age). The broiler chicken was compared to the slower growing layer chicken and the Pekin duck to its slower growing ancestor, the mallard. Two breeding lines of Pekin duck were also assessed. After gait assessment, the leg bones (femur and tibiotarsus) were scanned by computed tomography to measure morphological changes which have occurred due to selection for high growth and meat yield. Results were analysed by ANOVA, accounting for age and sex. During walking, heavy lines walked at a slower velocity, displayed a wider stance and spent more time supporting their mass on both feet than their lighter conspecifics, strategies which are likely to improve balance. The foot angle while walking differed between lines; all duck lines rotated their feet internally whereas the layer chickens’ feet were aligned with the direction of travel. Conversely the broiler chicken rotated its feet externally by seven weeks of age. Morphologically, the main differences were between species. Duck lines reached adult leg size earlier than chickens, which may be a response to differing adaptive environments prior to domestication. This early cessation of bone growth in ducks may provide more opportunity for the bones to remodel to handle the loads imposed on them. Lower levels of porosity and a unique cortical architecture observed in ducks endow relatively greater bone strength. Bone curvature also differed between species; the tibiotarsus curved more laterally in ducks than in chickens and may be a swimming adaptation that hinders locomotion on land in the modern production bird. In order to improve the objectivity of selection for better gait in poultry, the genetic parameters of gait components selected on the basis of results in this thesis were estimated using a linear mixed model in a population of Pekin ducks of known pedigree. As they are a simpler measure, similar or improved heritability estimates were estimated for these gait components when compared with the standard commercial gait score which is based on a subjective view of walking ability. Intense selection for economic traits has altered gait in similar ways in both species. To improve gait in poultry, greater breeding success may be achieved by focussing on those components of gait which have changed through selection, rather than using a subjective overall visual gait score. Furthermore, in both species, adaptations for pre-domesticated life may have affected the ability with which the selected lines have accommodated their gait to other morphological changes associated with increasing body mass.

Coordination indicates the ability to assemble and maintain a series of proper relations between joints or segments during motions. In Dynamical Systems Theory (DST), movement patterns are results of a synergistic organization of the neuromuscular system based on the constraints of anatomical structures, environmental factors, and movement tasks. Human gait requires the high level of neuromuscular control to regulate the initiation, intensity and adaptability of movements. To better understand how the neuromuscular system organizes and coordinates movements during walking, examination of single joint kinematics and kinetics alone may not be sufficient. Studying inter-joint coordination will provide insights into the essential timing and sequencing of neuromuscular control over biomechanical degrees of freedom, and the variability of inter-joint coordination would reflect the adaptability of such control. Previous studies assessing inter-joint coordination were mainly focused on neurological deficiencies, such as stroke or cerebral palsy. However, information on how inter-joint coordination is modulated with different constraints, such as walking speeds, aging, brain injury or joint dysfunctions, are limited. This knowledge could help us in identifying the potential risks during walking and improve the performance of individuals with movement impairments. The purpose of the present study was to investigate the properties of inter-joint coordination pattern and variability during walking with different levels of neuromuscular system perturbations using a DST approach, including an overall neuromuscular systemic degeneration, a direct insult to the brain, and a joint disease. We found that aging seemed to reduce the pattern adaptability of neuromuscular control. Isolated brain injury and joint disease altered the coordination pattern and exaggerated the variability, indicating a poor neuromuscular control. To improve gait performances for different populations, clinical rehabilitation should be carefully designed as different levels of neuromuscular system constraints would lead to different needs for facilitating appropriate coordinative movement. This dissertation includes both previously published/unpublished and coauthored material.

Cette thèse s’intéresse à définir de nouvelles méthodes cliniques d’investigation permettant de juger de l’impact de l’avance en âge sur la motricité. En particulier, cette thèse se focalise sur deux principales perturbations possibles lors de l’avance en âge : la chute et l’altération de la marche.Ces deux perturbations motrices restent encore mal connues et leur analyse en clinique pose de véritables défis technologiques et scientifiques. Dans cette thèse, nous proposons des méthodes originales de détection qui peuvent être utilisées dans la vie courante ou en clinique, avec un minimum de contraintes techniques.Dans une première partie, nous abordons le problème de la détection de la chute à domicile, qui a été largement traité dans les années précédentes. En particulier, nous proposons une approche permettant d’exploiter le volume du sujet, reconstruit à partir de plusieurs caméras calibrées. Ces méthodes sont généralement très sensibles aux occultationsqui interviennent inévitablement dans le domicile et nous proposons donc une approche originale beaucoup plus robuste à ces occultations. L’efficacité et le fonctionnement en temps réel ont été validés sur plus d’une vingtaine de vidéos de chutes et de leurres, avec des résultats approchant les 100% de sensibilité et de spécificité en utilisant 4 caméras ou plus.Dans une deuxième partie, nous allons un peu plus loin dans l’exploitation des volumes reconstruits d’une personne, lors d’une tâche motrice particulière : la marche sur tapis roulant, dans un cadre de diagnostic clinique. Dans cette partie, nous analysons plus particulièrement la qualité de la marche. Pour cela nous développons le concept d’utilisation de caméras de profondeur pour la quantification de l’asymétrie spatiale au cours du mouvement des membres inférieurs pendant la marche. Après avoir détecté chaque pas dans le temps, cette méthode réalise une comparaison de surfaces de chaque jambe avec sa correspondante symétrique du pas opposé. La validation effectuée sur une cohorte de 20 sujets montre la viabilité de la démarche / This thesis is concerned with defining new clinical investigation method to assess the impact of ageing on motricity. In particular, this thesis focuses on two main possible disturbance during ageing : the fall and walk impairment. This two motricity disturbances still remain unclear and their clinical analysis presents real scientist and technological challenges. In this thesis, we propose novel measuring methods usable in everyday life or in the walking clinic, with a minimum of technical constraints.In the first part, we address the problem of fall detection at home, which was widely discussed in previous years. In particular, we propose an approach to exploit the subject’s volume, reconstructed from multiple calibrated cameras. These methods are generally very sensitive to occlusions that inevitably occur in the home and we therefore propose an original approach much more robust to these occultations. The efficiency and realtime operation has been validated on more than two dozen videos of falls and lures, with results approaching 100 % sensitivity and specificity with at least four or more cameras.In the second part, we go a little further in the exploitation of reconstructed volumes of a person at a particular motor task : the treadmill, in a clinical diagnostic. In this section we analyze more specifically the quality of walking. For this we develop the concept of using depth camera for the quantification of the spatial and temporal asymmetry of lower limb movement during walking. After detecting each step in time, this method makes a comparison of surfaces of each leg with its corresponding symmetric leg in the opposite step. The validation performed on a cohort of 20 subjects showed the viability of the approach.

Robotic assisted partial knee arthroplasty (PKA) has gained in popularity as a treatment for end stage knee osteoarthritis (OA) that involves only one or two compartments of the knee over total knee arthroplasty (TKA). PKA surgeries are known for their less invasive and more precise treatment of medial or lateral compartmental (+/- patellofemoral) arthritis, improved postoperative range of motion, greater ligament and bone preservation, and a more natural gait. The Robotic Arm Interactive Orthopedic MAKO Stryker (RIO; MAKO Stryker, Fort Lauderdale, Florida) Robot has significantly improved PKA implant alignment by providing real-time feedback during surgery and improving three-dimensional implant placement accuracy. To assess kinematic differences between robotic assisted PKA and manual technique TKA, a 14-camera optoelectronic motion capture system (Optitrack, NaturalPoint, Corvallis, OR USA) was designed and installed in a hospital hallway to collect patient gait outcomes directly after clinic appointments. This thesis investigates the feasibility and validity results from setting up a motion capture system and its associated reliability when using it in a high traffic clinical environment. The first objective of this thesis was to investigate a total of 26 patients (14 TKA, 12 PKA) that underwent a kinematic gait assessment at 4-time points; preoperatively, and postoperatively (3,6,12 months). At 3 and 6 months postoperatively, the TKA group had improved knee flexion range of motion (ROM) during walking compared to the PKA group. This result was statistically significant (3-month p value =0.042, 6-month p value= 0.048). At 6 months, changes in the knee adduction/abduction angles were also significantly different (p value= 0.023), showing less knee ROM in the frontal plane after a PKA comparable to healthy controls. Despite differences in improvements in joint kinematics during walking between the two groups, these factors did not necessarily correlate with better perceived patient reported outcomes (PROMs). The results obtained from this pilot study display initial feasibility and suggest further research is required on a larger sample size to confirm if PKA surgeries are superior to TKA surgeries in terms of gait function. In conclusion, a repeatable, instrumented gait analysis was setup in a busy orthopedic hallway where reliable data can be collected. / Thesis / Master of Applied Science (MASc) / Robotic assisted partial knee replacements have been gaining popularity in recent years due to the perceived benefits over a total knee replacement such as preserving more bone, faster recovery, and improved walking outcomes. A partial knee replacement can either replace one or both compartments of the knee joint, depending on the level of arthritis in the patient's knee. This thesis investigated the differences in walking ability before and after surgery using a specialized system installed in the hospital to collect data during regularly scheduled appointments. Patients in this study either received a partial knee replacement with the help of a surgical robot, or a regular total knee replacement. The results showed that there is a significant difference in how much the knee moves during walking between patients who had the robot surgery and those who had the usual surgery. However, the patient’s experience and their perception of how well they were doing after surgery were not different between the two surgeries. This study provided valuable insight into the current surgical treatments available for knee arthritis.

Gait recognition systems have gained tremendous attention due to its potential applications in healthcare, criminal investigation, sports biomechanics, and so forth. A new solution to gait recognition tasks can be provided by wearable sensors integrated in wearable objects or mobile devices. In this research a sock prototype designed with embedded soft robotic sensors (SRS) is implemented to measure foot ankle kinematic and kinetic data during three experiments designed to track participants’ feet ankle movement. Deep learning and statistical methods have been employed to model SRS data against Motion capture system (MoCap) to determine their ability to provide accurate kinematic and kinetic data using SRS measurements. In the first study, the capacitance of SRS related to foot-ankle basic movements was quantified during the gait movements of twenty participants on a flat surface and a cross-sloped surface. I have conducted another study regarding kinematic features in which deep learning models were trained to estimate the joint angles in sagittal and frontal planes measured by a MoCap system. Participant-specific models were established for ten healthy subjects walking on a treadmill. The prototype was tested at various walking speeds to assess its ability to track movements for multiple speeds and generalize models for estimating joint angles in sagittal and frontal planes. The focus of the last study is measuring the kinetic features and the goal is determining the validity of SRS measurements, to this end the pressure data measured with SRS embedded into the sock prototype would be compared with the force plate data.

Background: Youth sports participation has numerous positive mental and physical health benefits. In young athletes, injuries result in millions of emergency room visits and millions of dollars spent every year offsetting many of the positive benefits gained by participation in sports. An increase in traumatic injury rates has been found to occur during the year of peak height growth (PHV), with a subsequent increase in risk of overuse injury in the years immediately following. This may be the result of changes to movement coordination around the time of adolescent growth spurts, a phenomenon called adolescent motor awkwardness (AMA). Though this phenomenon is well known to parents and coaches of young athletes, scientific research into its causes, symptoms, and timeline remains sparse. Minimal scientific evidence exists to quantify the impact of AMA on specific areas of movement coordination (ex. gait) and muscle performance, as well as its relation to growth spurts. Equally as poorly understood are the potential causes of motor disruptions during this period. As adolescents experience a wide variety of alterations to body size, proportions, and composition during puberty, there are many factors which could lead to disruptions to movement coordination. Additionally, there are substantial differences which arise in body proportions and composition between the sexes during puberty, yet any between-sex-group differences in the timeline, causes, or specific changes to movement coordination have not yet been explored. Purpose: The purpose of this dissertation was threefold: 1) To understand how gait stability changes with age and height during adolescence, and how these changes differ between the sexes (aim 1; chapter 2); 2) To understand the immediate effects of physical growth on gait smoothness during adolescence (aim 2; chapter 3); 3) To understand how peripheral fatigue affects gait smoothness during adolescence, and to understand how physical growth impacts muscular fatigability (aim 3; chapter 4). Participants: Sixty-Seven individuals (n=34 female, n=33 male) participated in the first study session to obtain Harmonic Ratio (HR), age, height, and fatigue data for aims 1 and 3. A subset of 46 participants (n=20 female, n=26 male) returned to participate in a second study session to obtain growth rate, HR, and fatigue data for aims 2 and 3. Methods: The testing protocol used in both sessions was identical. Trigno sensors were adhered to the participants skin at four locations determined by manual palpation: C7, L5, and the right and left rectus femoris. Once sensors were secured, participants completed a 15-minute treadmill warm-up in which their self-reported preferred walking speed was obtained. Following the warm-up, participants completed two 9-minute treadmill walking trials at three set speeds: 70% (slow walking speed; SWS), 100% (preferred walking speed; PWS), and 130% (Fast Walking Speed; FWS) of preferred walking speed. The walking trials were separated by a 10-minute leg-focused fatigue protocol. During each walking trial, accelerations of the upper (C7) and lower (L5) trunk were recorded in three planes of motion: Anterior-Posterior (AP), Medio-Lateral (ML), and Vertical (V). Harmonic Ratios were calculated from these acceleration signals. Prior to beginning each walking trial (i.e., pre-fatigue and post-fatigue) surface electromyography (sEMG) of the right and left rectus femoris was obtained during a 10-second sustained maximal contraction. Median frequency (Fmed) of this sEMG signal was used to calculate muscular fatigue level before and after the fatiguing protocol. Descriptive statistics were calculated for both the first session group and the second session subgroup. To accomplish aim 1, relationships between age, height, and HRs were assessed using multiple linear regression models with Holm-Bonferroni correction. Gait and anthropometric characteristics were compared by sex using independent sample t-tests. To accomplish aim 2, associations between growth rate and HRs were assessed through multiple linear regression adjusted for age and height. To accomplish aim 3, pre- and post- fatigue HRs were compared within subjects using paired t-tests. The association between muscular fatigability and growth rate was assessed using linear regression. Results: In aim 1, male and female groups differed significantly in height, age, and gait speeds. HRs improved with age for females at C7AP at all speeds pre-fatigue and at C7V in SWS and PWS post-fatigue. Males’ HRs increased with age during FWS pre-fatigue at C7V, C7AP , and L5ML . Females had a significant negative association between height and HR post-fatigue at C7V during both SWS and PWS, and at C7AP during FWS. In aim 2, male and female groups differed significantly in height, but not in age, growth rate (GR), walking speeds, or average HRs. When accounting for age and height, GR over a four-month period was a significant linear predictor of smoothness of trunk motion only for females during fast walking at L5AP. In aim 3, Females showed a significant effect of fatigue at SWS and at PWS on smoothness of motion of the lower trunk. Males showed a significant effect of fatigue during FWS at C7 in all planes of motion. Conclusions: These findings overall suggest substantial sex differences in changes to smoothness of trunk motion during gait in adolescents and in the effects of fatigue on trunk smoothness. In aim 1, several HRs improved with age in both sexes, but benefits were eliminated with fatigue in males. Aim 2 suggests that physical growth does not have immediate impacts on HR in adolescence. The results of aim 3 show substantial differences between the sexes in how muscular fatigue impacts gait stability. Males were most affected by fatigue at the upper trunk, particularly at FWS, while females were most affected by fatigue at the lower trunk at PWS. / Physical Therapy

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With the rise of the Internet of Things (IoT) and smart buildings, new algorithms are being developed to understand how occupants are interacting with buildings via structural vibration measurements. These vibration-based occupant inference algorithms (VBOI) have been developed to localize footsteps within a building, to classify occupants, and to monitor occupant health. This dissertation will present a three-stage journey proposing a path forward for VBOI research based on physically informed data-driven models of structural dynamical systems. The first part of this dissertation presents a method for extracting temporal gait parameters via underfloor accelerometers. The time between an occupant's consecutive steps can be measured with only structural vibration measurements with a similar accuracy to current gait analysis tools such as force plates and in-shoe pressure sensors. The benefit of this, and other VBOI gait analysis algorithms, is in their ease of use. Gait analysis is currently limited to a clinical setting with specialized measurement systems, however VBOI gait analysis provides the ability to bring gait analysis to any building. VBOI algorithms often make some simplifying assumptions about the dynamics of the building in which they operate. Through a calibration procedure, many VBOI algorithms can learn some system parameters. However, as demonstrated in the second part of this dissertation, some commonly made assumptions oversimplify phenomena present in civil structures such as: attenuation, reflections, and dispersion. A series of experimental and theoretical investigations show that three common assumptions made in VBOI algorithms are unable to account for at least one of these phenomena, leading to algorithms which are more accurate under certain conditions. The final part of this dissertation introduces a physically informed data-driven modelling technique which could be used in VBOI to create a more complete model of a building. Continuous residue interpolation (CRI) takes FRF measurements at a discrete number of testing locations, and creates a predictive model with continuous spatial resolution. The fitted CRI model can be used to simulate the response at any location to an input at any other location. An example of using CRI for VBOI localization is shown. / Doctor of Philosophy / Vibration-based occupant inference (VBOI) algorithms are an emerging area of research in smart buildings instrumented with vibration sensors. These algorithms use vibration measurements of the building's structure to learn something about the occupants inside the building. For example the vibration of a floor in response to a person's footstep could be used to estimate where that person is without the need for any line-of-sight sensors like cameras or motion sensors. The storyline of this dissertation will make three stops: The first is the demonstration of a VBOI algorithm for monitoring occupant health. The second is an investigation of some assumptions commonly made while developing VBOI algorithms, seeking to shed light on when they lead to accurate results and when they should be used with caution. The third, and final, is the development of a data-driven modelling method which uses knowledge about how systems vibrate to build as detailed a model of the system as possible. Current VBOI algorithms have demonstrated the ability to accurately infer a range of information about occupants through vibration measurements. This is shown with a varied literature of localization algorithms, as well as a growing number of algorithms for performing gait analysis. Gait analysis is the study of how people walk, and its correlation to their health. The vibration-based gait analysis procedure in this work demonstrates extracting distributions of temporal gait parameters, like the time between steps. However, many current VBOI algorithms make significant simplifying assumptions about the dynamics of civil structures. Experimental and theoretical investigations of some of these assumptions show that while all assumptions are accurate in certain situations, the dynamics of civil structures are too complex to be completely captured by these simplified models. The proposed path forward for VBOI algorithms is to employ more sophisticated data-drive modelling techniques. Data-driven models use measurements from the system to build a model of how the system would respond to new inputs. The final part of this dissertation is the development of a novel data-driven modelling technique that could be useful for VBOI. The new method, continuous residue interpolation (CRI) uses knowledge of how systems vibrate to build a model of a vibrating system, not only at the locations which were measured, but over the whole system. This allows a relatively small amount of testing to be used to create a model of the entire system, which can in turn be used for VBOI algorithms.

Decreased gait symmetry has been correlated with an increased fall risk, abnormal joint loading and decreased functional outcomes. Therefore, symmetry is focused on in the rehabilitation of many patient populations. Currently, load based symmetry is collected using expensive and immobile devices that are not clinically accessible, but there is a clinical need for an objective measure of loading symmetry during daily tasks like walking. Therefore, the purpose of this dissertation was to 1) assess the validity and reliability of the loadsol® to capture ground reaction force data, 2) use the loadsol® to determine the differences in symmetry between adults with a TKA and their healthy peers and 3) explore the potential of a commercially available biofeedback system to acutely improve gait symmetry in adults. The results of this work indicate that the loadsol® is a valid and reliable method of collecting loading measures during walking in both young and older adults. TKA patients who are 12-24 months post-TKA have lower symmetry in the weight acceptance peak force, propulsive peak force and impulse when compared to their healthy peers. Finally, a case study with four asymmetric adults demonstrated that a 10-minute biofeedback intervention with the loadsol® resulted in an acute improvement in symmetry. Future work is needed to determine the potential of this intervention to improve symmetry in patient populations and to determine whether the acute response is retained following the completion of the intervention. / Doctor of Philosophy / Symmetry during walking is a valuable attribute as asymmetry has been correlated with an increased fall risk and decreased mobility. Currently, load based symmetry is collected using expensive and immobile devices that are not clinically accessible. As a result, there is a critical need for a system that can objectively measure load and loading symmetry during rehabilitation and everyday tasks in a variety of settings. A new device has been developed (loadsol®) that could potentially fill this need. Before it can be used to assess and treat patients, the loadsol® needed to be assessed for accuracy and reliability in both older and younger adults and at various speeds. Then we needed to determine if the loadsol® can be used to look at the levels of symmetry in patients who have had a knee replacement compared to their healthy peers. Finally, we tested a visual biofeedback intervention with the loadsol® to see if this intervention was able to improve symmetry. We found that the loadsol® is accurate and reliable. Patients with a knee replacement were less symmetric than their age matched peers. Finally, in a small study, the visual biofeedback intervention improved symmetry during walking in a group of people with less than 90% symmetry. Future work is needed to explore the potential of this biofeedback intervention to improve symmetry in various patient populations and to determine the extent to which patients are able to retain these improvements.