L’analyse de la marche a émergé comme l’un des domaines médicaux le plus im- portants récemment. Les systèmes à base de marqueurs sont les méthodes les plus fa- vorisées par l’évaluation du mouvement humain et l’analyse de la marche, cependant, ces systèmes nécessitent des équipements et de l’expertise spécifiques et sont lourds, coûteux et difficiles à utiliser. De nombreuses approches récentes basées sur la vision par ordinateur ont été développées pour réduire le coût des systèmes de capture de mou- vement tout en assurant un résultat de haute précision. Dans cette thèse, nous présentons notre nouveau système d’analyse de la démarche à faible coût, qui est composé de deux caméras vidéo monoculaire placées sur le côté gauche et droit d’un tapis roulant. Chaque modèle 2D de la moitié du squelette humain est reconstruit à partir de chaque vue sur la base de la segmentation dynamique de la couleur, l’analyse de la marche est alors effectuée sur ces deux modèles. La validation avec l’état de l’art basée sur la vision du système de capture de mouvement (en utilisant le Microsoft Kinect) et la réalité du ter- rain (avec des marqueurs) a été faite pour démontrer la robustesse et l’efficacité de notre système. L’erreur moyenne de l’estimation du modèle de squelette humain par rapport à la réalité du terrain entre notre méthode vs Kinect est très prometteur: les joints des angles de cuisses (6,29◦ contre 9,68◦), jambes (7,68◦ contre 11,47◦), pieds (6,14◦ contre 13,63◦), la longueur de la foulée (6.14cm rapport de 13.63cm) sont meilleurs et plus stables que ceux de la Kinect, alors que le système peut maintenir une précision assez proche de la Kinect pour les bras (7,29◦ contre 6,12◦), les bras inférieurs (8,33◦ contre 8,04◦), et le torse (8,69◦contre 6,47◦). Basé sur le modèle de squelette obtenu par chaque méthode, nous avons réalisé une étude de symétrie sur différentes articulations (coude, genou et cheville) en utilisant chaque méthode sur trois sujets différents pour voir quelle méthode permet de distinguer plus efficacement la caractéristique symétrie / asymétrie de la marche. Dans notre test, notre système a un angle de genou au maximum de 8,97◦ et 13,86◦ pour des promenades normale et asymétrique respectivement, tandis que la Kinect a donné 10,58◦et 11,94◦. Par rapport à la réalité de terrain, 7,64◦et 14,34◦, notre système a montré une plus grande précision et pouvoir discriminant entre les deux cas. / Gait analysis has emerged as one of the most important medical field recently due to its wide range of applications. Marker-based systems are the most favoured methods of human motion assessment and gait analysis, however, these systems require specific equipment and expertise, and are cumbersome, costly and difficult to use. Many re- cent computer-vision-based approaches have been developed to reduce the cost of the expensive motion capture systems while ensuring high accuracy result. In this thesis, we introduce our new low-cost gait analysis system that is composed of two low-cost monocular cameras (camcorders) placed on the left and right sides of a treadmill. Each 2D left or right human skeleton model is reconstructed from each view based on dy- namic color segmentation, the gait analysis is then performed on these two models. The validation with one state-of-the-art vision-based motion capture system (using the Mi- crosoft Kinect v.1) and one ground-truth (with markers) was done to demonstrate the robustness and efficiency of our system. The average error in human skeleton model estimation compared to ground-truth between our method vs. Kinect are very promis- ing: the joints angles of upper legs (6.29◦ vs. 9.68◦), lower legs (7.68◦ vs. 11.47◦), feet (6.14◦ vs. 13.63◦), stride lengths (6.14cm vs. 13.63cm) were better and more stable than those from the Kinect, while the system could maintain a reasonably close accu- racy to the Kinect for upper arms (7.29◦ vs. 6.12◦), lower arms (8.33◦ vs. 8.04◦), and torso (8.69◦ vs. 6.47◦). Based on the skeleton model obtained by each method, we per- formed a symmetry study on various joints (elbow, knee and ankle) using each method on two different subjects to see which method can distinguish more efficiently the sym- metry/asymmetry characteristic of gaits. In our test, our system reported a maximum knee angle of 8.97◦ and 13.86◦ for normal and asymmetric walks respectively, while the Kinect gave 10.58◦ and 11.94◦. Compared to the ground-truth, 7.64◦ and 14.34◦, our system showed more accuracy and discriminative power between the two cases.

ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Even after rehabilitation, patients with lower-limb amputation may continue to exhibit suboptimal gait. A wireless telemetry system, featuring force sensors, accelerometers, control electronics and a Bluetooth transmission module was developed to measure plantar pressure information and remotely monitor patient mobility. Plantar pressure characterization studies were performed to determine the optimal sensor placement. Finally, the wireless telemetry system was integrated with a previously developed haptic feedback system in order to allow remote monitoring of patient mobility during haptic system validation trials.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / Falls prevention efforts for older adults have become increasingly important and are now a significant research effort. As part of the prevention effort, analysis of gait has become increasingly important. Data is typically collected in a laboratory setting using 3-D motion capture, which can be time consuming, invasive and requires expensive and specialized equipment as well as trained operators. Inertial sensors, which are smaller and more cost effective, have been shown to be useful in falls research. Smartphones now contain Micro Electro-Mechanical (MEM) Inertial Measurement Units (IMUs), which make them a compelling platform for gait data acquisition. This paper reports the development of an iOS app for collecting accelerometer data and an offline machine learning system to classify a subject, based on this data, as faller or non-faller based on their history of falls. The system uses the accelerometer data captured on the smartphone, extracts discriminating features, and then classifies the subject based on the feature vector. Through simulation, our preliminary and limited study suggests this system has an accuracy as high as 85%. Such a system could be used to monitor an at-risk person's gait in order to predict an increased risk of falling.

Thesis (MScPhysio)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: BACKGROUND: A functional gait forms an integral part of life, allowing individuals to function within their environment and participate in activities of daily living. The evaluation of gait forms an essential part of a physical examination and can help screen for physical impairments. To the researchers‟ knowledge no 3D gait analysis studies of this nature have been conducted in South Africa. South African gait analysis laboratory protocols and procedures may differ from laboratories in other countries; therefore a South African data base of normative values is required to make a valid assessment of South African children‟s gait. OBJECTIVE: The aim of this study is to describe kinematics and spatiotemporal parameters of gait of typically developed children between the ages of 6-10 years in the Cape Metropole of the Western Cape, South Africa. METHODOLOGY: A descriptive study was conducted. Twenty-eight typically developed children were conveniently sampled from aftercare facilities and schools were performed in the Cape Metropole in the Western Cape, South Africa. The three-dimensional (3D) lower limb kinematics and spatiotemporal parameters of gait were analyzed. For data capture, the lower limb Plug-in-Gait (PIG) marker placement was used. Participants were asked to walk bare footed at self-selected speed. Due to a small sample size, children were also sub-divided into two groups (Group A: 6-8 years and Group B: 9-10 years) for comparison. Means and standard deviations (SD) were calculated for all outcomes, followed by statistical tests to determine significant differences between the two sub-groups for spatiotemporal parameters and kinematics. RESULTS: There was a significant difference between the sub-groups for all the non-normalized spatiotemporal parameters. A statistical significant difference between the sub-groups for the mean hip rotation minimum values (p=0.036) was found. There was no significant difference between the sub-groups for any other kinematic parameter or when comparing the normalized spatiotemporal parameters. CONCLUSION: This study provides descriptive gait parameters that can be used for comparison or gait analysis purposes. Our results suggest that normalized spatiotemporal parameters showed no significant difference between the age groups and are consistent with international children‟s spatiotemporal parameters. Kinematic values showed significant changes with hip rotation. Older children had more external rotation at their hips. KEYWORDS: 3D gait analysis, walking, children, spatiotemporal parameters, kinematics. / AFRIKAANSE OPSOMMING: INLEIDING: „n Funksionele stap is „n essensiële deel van die lewe wat mens toelaat om in jou omgewing te funksioneer en om deel te neem aan daaglikse aktiwiteite. Evaluasie van stap is „n belangrike deel van die fisiese evaluasie en kan help om te sif vir fisiese verswakking of abnormaliteite. So ver hierdie navorsers weet, is hierdie die eerste loop analise studie van sy soort wat in Suid-Afrika onderneem is. Suid-Afrikaanse stap-evaluasie-labrotorium protokols en prosedures mag ook dalk verskil van die in ander lande. Dus is „n Suid-Afrikaanse databasis vir normale waardes van loop nodig om „n gegronde evaluasie van Suid-Afrikaanse kinders se loopgang te kan maak. DOELWIT: Die doel van hierdie studie is om die kinematika en spatiotemporale parameters van loop te omskryf in tipies ontwikkelde kinders tussen die ouderdom van 6-10 jaar in die Kaapse Metropool en om die bevindinge tussen die twee ouderdomsgroepe te vergelyk. METODE: „n Beskrywende studie is uitgevoer. Ag-en-twintig tipies ontwikkelde kinders is van skole en nasorgfasiliteite in die Kaapse Metropool in die Wes-Kaap, Suid-Afrika gewerf. Die drie-dimensionele (3D) onderste ledemaat se kinematika en spatiotemporale parameters van loop is geanaliseer. Vir data insameling is die onderste ledemaat Plug-in-Gait (PIG) merker-plasing gebruik. Deelnemers is gevra om kaalvoet teen hulle eie spoed te stap. Die kinders is in die verskeie ouderdomsgroepe verdeel, maar as gevolg van klein toetsgroepgetalle, is hulle sub-verdeel in twee groepe (Groep A: 6-8 jaar en Groep B: 9-10 jaar). Beskrywende statistiese tegnieke is gebruik vir alle uitkoms maatreëls. Gemiddeldes en standaardafwykings (SA) was bereken, om beduidende verskille tussen die ouderdomsgroepe en sub-groepe te bepaal. RESULTATE: Daar is „n beduidende verskil tussen die jonger en ouer kinders vir nie-genormaliseerde spatiotemporale parameters, asook „n beduidende verskil tussen die sub-groepe vir die gemiddelde heuprotasie minimum waardes (p=0.036). Daar was geen beduidende verskil tussen die twee groepe met die ander kinematiese parameters of met genormaliseerde spatiotemporale parameters van die sub-groepe nie. GEVOLGTREKKING: Hierdie studie verskaf beskrywende statistiese data van stap-parameters wat gebruik kan word vir vergelyking met ander kinders van dieselfde ouderdomme of loop-analise doeleindes. Ons bevindinge stel voor dat genormaliseerde spatiotemporale parameters geen beduidende bevindings aandui tussen die verskeie ouderdomsgroepe nie. Dit is ook konsekwent met internasionale kinders se spatiotemporale parameterwaardes. Kinematisie waardes het beduidende verskille in heuprotatsie getoon. Ouer kinders het meer eksterne rotasie in hulle heupe in vergelyking met jonger kinders. Soos die kinders ontwikkel, verminder die heup-anteversie en die heup beweeg vanaf interne rotasie na „n relatiewe eksterne rotasie.

It has been suggested that Patellofemoral Pain (PFP) may be the result of a coordinate state which exhibits less joint coordination variability. The ability to relate joint coordination variability to PFP pathology could have many clinical uses; however, evidence to support clinical application is lacking. Vector coding’s coupling angle variability (CAV) has been introduced as a possible analysis method to quantify joint coordination variability. The purpose of this study was to assess the clinical usefulness of CAV measures from a dynamical systems perspective. This involved establishing the precision limits of CAV measures when physiological conditions are held constant, altering control parameters of knee pain and population then determining if the observed changes in CAV were clinically meaningful. 20 female recreational runners with PFP and 21 healthy controls performed a treadmill acclimation protocol then ran at a self-selected pace for 15 minutes. 3-D kinematics, force plate kinetics, knee pain and perceived exertion were recorded each minute. CAV were calculated for six knee-ankle combinations for 2 sets of 5 non-consecutive stride cycles at each capture period. Data were selected for the PFP group at a high (=>3) and low (<=high-2) pain level in a non-exhausted state (<14). Healthy data were used from the 11th minute of the running. Levels of agreement were performed between the 2 sets of CAV measures for both populations, a paired t-test compared low to high pain CAV measures and independent t-tests compared populations at the high pain state. Several CAV measures showed a significant increase in value with an increase in pain and were significantly greater for the PFP group. None of the observed changes exceeded the precision limits of all CAV measures investigated. These results do not agree with previous claims that less variability is indicative of pathology but rather the opposite. This suggests that there might be an optimal amount of variability to maintain a healthy coordinate state with deviations in any direction being detrimental. However; due to the volatile nature of CAV measures, the clinical use of CAV is not recommended using current analysis methods since changes observed weren’t considered clinically meaningful.

No description available.

The rollator is a mobility aid commonly used to facilitate balance and mobility for individuals with cardiorespiratory, musculoskeletal, or neurological deficits. Despite its popularity, there are also reports of adverse effects related to walker use linked to increased fall risks. Studies examining the effectiveness and consequences of rollator use have employed standard laboratory-based measurement methods that rely on performing specific tasks within a short time period and under controlled conditions, potentially limiting generalization to mobility in the everyday context. An instrumented rolling walker (iWalker) was developed as an ambulatory measurement tool applicable to the assessment of balance outside of the lab or clinic for assistive device users. The iWalker autonomously collects measurements of the upper and lower limb behaviour related to balance, walker kinematics, and video of the immediate spatial environment. The design and development of the iWalker is first described, followed by two studies characterizing the involvement of the upper limbs for balance in standing and walking that served to address gaps in the literature and evaluate the utility of the upper limb measures. Overall, the upper limbs can become the primary effectors of balancing forces when lower limb capabilities are compromised. When lower limb involvement was experimentally constrained, the upper limbs became the primary effectors of balance control in healthy, young adults. In older adults, individuals demonstrating the highest upper limb usage during walking were associated with the largest reduction in frontal plane stepping parameters (i.e., step width). A third study evaluated the applicability of the iWalker to assess everyday mobility in a series of in-patients recovering from neurological injury (i.e., stroke, traumatic brain injury). Patients demonstrated significantly different upper limb balancing behaviour in everyday situations compared to in-laboratory assessments. Furthermore, the iWalker captured behaviours that may be precursors to falling, such as collisions, stumbling and lifting the assistive device. The implications of these studies on assessing the effectiveness of rollators and feasibility of using the iWalker in follow-up efforts are discussed.

Background: Stroke survivors often have persistent neural deficits related to motor function and sensation, which increase their risk of falling, most of which occurs at home or in community settings. The use of wearable technology to monitor fall risk and gait in stroke survivors may prove useful in enhancing recovery and/or preventing injuries. Objective: Determine the feasibility of using wearable technology (PAMSys (TM)) to objectively monitor fall risk and gait in home and community settings in stroke survivors. Methods: In this feasibility study, we used the PAMSys to identify fall risk indicators (postural transitions: duration in seconds, and number of unsuccessful attempts), and gait (steps, speed, duration) for 48 hours during usual daily activities in stroke survivors (n=10) compared to age-matched controls (n=10). A questionnaire assessed device acceptability. Results: Stroke survivors mean age was 70 +/- 8 years old, were mainly Caucasian (60%) women (70%), and not significantly different than the age-matched controls (all P-values >0.20). Stroke survivors (100%) reported that the device was comfortable to wear, didn't interfere with everyday activities, and were willing to wear it for another 48 hours. None reported any difficulty with the device while sleeping, removing/putting back on for showering or changing clothes. When compared to controls, stroke survivors had significantly worse fall risk indicators and walked less (P<0.05). Conclusion: Stroke survivors reported high acceptability of 48 hours of continuous PAMSys monitoring. The use of in-home wearable technology may prove useful in monitoring fall risk and gait in stroke survivors, potentially enhancing recovery.

Currently, gait rehabilitation for gait deviations associated with stroke has focused on task-specific repetitive rehabilitation techniques. Body weight supported treadmill training has been used to administer this type of rehabilitation but is labor intensive for therapists. To alleviate the burden on therapists, mechanized or robotic gait trainers have been used to elicit gait-like movements. This study is focused on evaluating an elliptical trainer that was modified to provide an ankle articulation pattern similar to that found in normal gait. The kinematic, kinetic, and metabolic effect of the modifications on normal subjects was evaluated. Eight healthy adult subjects (4 male, 4 female; mean age 28.6 ± 5.2) participated in this research. Subjects were asked to ambulate on the elliptical trainer with and without the modifications at two metronome-paced speeds (1Hz and 1.5Hz). Video-based motion analysis techniques were used to collect sagittal plane kinematic data at a rate of 30 Hz. Reflective markers were placed over the acromion, greater trochanter, fibular head, lateral malleolus, heel, and fifth metatarsal. Metabolic Energy – The rate of energy consumption (VO2 consumption and VCO2 production) was measured using ventilatory expired gas analysis (SensorMedics, Yorba Linda, CA). The articulation of the footplate on the modified elliptical trainer correlated with the foot movement seen in normal ambulation (r2=0.89). It was found that for the ankle and knee, the joint angles while ambulating on the modified elliptical trainer correlated better to normal gait than the non-modified elliptical trainer. However, the hip angles were found to correlate worse. This suggests that the ankle articulation was successful, but the distal control was not as effective as expected. Kinetic energy was found to not be significantly different between the modified elliptical trainer and the non-modified elliptical trainer. Metabolic energy was found to be statistically higher on the modified elliptical trainer (p=0.001). This may suggests that there is co-contraction of muscles around joints. Further study using electromyography may provide further insight on the difference seen in metabolic energy consumption.

In response to the potential benefits of task specific training in rehabilitation of gait after stroke and the need for affordable, simple ways to implement it, our group designed the elliptically based robotic gait trainer (EBRGT). A design review of the EBRGT, covering the design goals, an overview of the mechanical and electrical design, and a discussion of the novelty of the device and why it may be beneficial for individuals with hemiparesis secondary to stroke is discussed (Chapter 2). To characterize the new device, a study was performed to determine if the EBRGT produced a gait pattern that mimicked level surface walking in healthy adults (chapter 3). Sagittal plane kinematic analysis suggested the EBRGT produced joint movement patterns that are similar to level surface walking at the hip and knee with less similarity between activities at the ankle. Electromyography (EMG) revealed that the EBRGT induced a cyclic muscle firing pattern that had some similarities when compared to level surface walking. We also examined the feasibility of ambulatory individuals after stroke to use the EBRGT and if their movement patterns were similar to healthy adults walking on the same device (Chapter 4). All six participants were able to walk on the device with minimal assistance. These participants had joint kinematics and EMG similar to healthy adults, suggesting that individuals with hemiparesis perform a gait like movement when using the EBRGT. Lastly, a study was performed to determine if the EBRGT could improve gait parameters and function in ambulatory individuals with hemiparesis after stroke (chapter 5). Four participants walked on the EBRGT 3x/week for 4 or 8 weeks. After the intervention, all 4 participants increased their preferred gait speed. One participant had an improvement in gait speed that indicated functional gains. The results of this research suggest that the EBRGT can produce a gait pattern that has some similarities to level surface walking and that it is feasible for ambulatory individuals with hemiparesis to use the device. The device may also improve gait parameters in ambulatory individuals after stroke, but future studies with a control group need to be performed.