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.

amputation, which includes reduced force generation at the knee and ankle, reduced control of the leg, and different mass properties relative to their intact leg. The physical change in the prosthetic leg leads to gait asymmetries that include spatial, temporal, or force differences. This altered gait can lead to an increase in energy consumption and pain due to compensating forces and torques. The asymmetric prosthesis demonstrated in this research aims to find a balance between the different types of asymmetries to provide a gait that is more symmetric and to make it overall easier for an amputee to walk. Previous research has shown that a passive dynamic walker (PDW) with an altered knee location can exhibit a symmetric step length. An asymmetric prosthetic simulator was developed to emulate this PDW with an altered knee location. The prosthetic simulator designed for this research had adjustable knee settings simulating different knee locations. The prosthetic simulator was tested on able-bodied participants with no gait impairments. The kinetic and kinematic data was obtained using a VICON motion capture system and force plates. This research analyzed the kinematic and kinetic data with different knee locations (high, medium, and low) and normal walking. This data was analyzed to find the asymmetries in step length, step time, and ground reaction forces between the different knee settings and normal walking. The study showed that there is symmetry in step lengths for all the cases in overground walking. The knee at the lowest setting was the closest in emulating a normal symmetric step length. The swing times for overground walking showed that the healthy leg swings at almost the same rate in every trial and the leg with the prosthetic simulator can either be symmetric, like the healthy leg or has a higher swing time. Step lengths on the treadmill also showed a similar pattern, and step length of the low knee setting were the closest to the step length of normal walking. The swing times for treadmills did not show a significant trend. Kinetic data from the treadmill study showed that there was force symmetry between the low setting and normal walking cases. In conclusion these results show that a low knee setting in an asymmetric prosthesis may bring about spatial and temporal symmetry in amputee gait. This research is important to demonstrate that asymmetries in amputee gait can be mitigated using a prosthesis with a knee location dissimilar to that of the intact leg. Tradeoffs have to be made to achieve symmetric step length, swing times, or reaction forces. A comprehensive study with more subjects has to be conducted in-order to have a larger sample size to obtain statistically significant data. There is also opportunity to expand this research to observe a wider range of kinetic and kinematic data of the asymmetric prosthesis.

Recent interest in using passive dynamic walkers (PDWs) for gait rehabilitation studies has presented a need for a robust, easily built mechanism. Unfortunately, these passive robots are hypersensitive to many variables outside of the usual design considerations that are studied when constructing them. By accentuating previous failures instead of suppressing them, this thesis presents a number of problematic situations commonly experienced when testing and tuning a PDW. Further, through a complete design of a 4-legged PDW with knees, simple design axioms brought about by myself and others are put into a practical context and applied directly to design. This thesis aspires to present a systematic design process, and highlight how a computational model can be used with both hand calculations and CAD packages. Using the insight from those researchers before me, I strive to further their designs and present relevant information in a design compendium that makes it more useful to those who have an application for the device. This thesis resulted in two novel designs for a PDW. First, a changing radius foot was developed to increase knee flexion upon toe off. The decrease in radius increases joint angular velocity resulting in ramp up. Further investigation of these feet could result in more stable and efficient walking patterns. The other design brought to attention is the planar crossbar mechanism for coupling the inner and outer legs. The crossbar provides a rigid coupling without changing the rotational inertia between the coupled pair about the hip axis.

abstract: According to the Center for Disease Control and Prevention report around 29,668 United States residents aged greater than 65 years had died as a result of a fall in 2016. Other injuries like wrist fractures, hip fractures, and head injuries occur as a result of a fall. Certain groups of people are more prone to experience falls than others, one of which being individuals with stroke. The two most common issues with individuals with strokes are ankle weakness and foot drop, both of which contribute to falls. To mitigate this issue, the most popular clinical remedy given to these users is thermoplastic Ankle Foot Orthosis. These AFO's help improving gait velocity, stride length, and cadence. However, studies have shown that a continuous restraint on the ankle harms the compensatory stepping response and forward propulsion. It has been shown in previous studies that compensatory stepping and forward propulsion are crucial for the user's ability to recover from postural perturbations. Hence, there is a need for active devices that can supply a plantarflexion during the push-off and dorsiflexion during the swing phase of gait. Although advancements in the orthotic research have shown major improvements in supporting the ankle joint for rehabilitation, there is a lack of available active devices that can help impaired users in daily activities. In this study, our primary focus is to build an unobtrusive, cost-effective, and easy to wear active device for gait rehabilitation and fall prevention in individuals who are at risk. The device will be using a double-acting cylinder that can be easily incorporated into the user's footwear using a novel custom-designed powered ankle brace. The device will use Inertial Measurement Units to measure kinematic parameters of the lower body and a custom control algorithm to actuate the device based on the measurements. The study can be used to advance the field of gait assistance, rehabilitation, and potentially fall prevention of individuals with lower-limb impairments through the use of Active Ankle Foot Orthosis. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2020

<p>Body weight supported devices available to enhance locomotor recovery following an incomplete spinal cord injury (SCI) include treadmills with (Lokomat^TM) and without (Manual Treadmill) robotic assistance, and the overground ZeroG^TM system. Cardiovascular and muscular demands of these devices were compared during steady-state locomotion at the <em>same</em> level of body weight support (BWS) in 7 individuals with incomplete SCI (42.6±4.29 years) and matched able-bodied controls (CON). Questionnaires evaluated consumer preference based on walking experience. Oxygen uptake (VO₂), heart rate (HR) and ratings of perceived exertion (RPE) were expressed as percentage of peak values obtained using arm ergometry. Additionally, VO₂ was expressed relative to resting metabolic equivalents (METS). Filtered electromyography (EMG) signals from tibialis anterior (TA), rectus femoris (RF), biceps femoris (BF) and medial gastrocnemius (MG) were normalized to ZeroG^TMstepping. Lokomat^TM sessions were the least demanding in terms of oxygen uptake compared to the Manual Treadmill and ZeroG^TM, and considered the least appropriate device for the SCI group’s current level of function. For SCI, the a) ZeroG^TM required 3.0 METS, 54.7% of VO₂peak, 84.7% of peak HR, b) Manual Treadmill required 2.8 METS, 52.9% of VO₂peak, 80.8% of peak HR and c) Lokomat^TM required 1.7 METS, 30.1% of VO₂peak, 67.3% of peak HR. Central RPEs were 3.8, 3.7, 0.5 and peripheral RPEs were 5.1, 4.1, 0.7 for the ZeroG^TM, Manual Treadmill and Lokomat^TM respectively. For CON, walking required minimal effort (at most 31.5% of VO₂ peak), with ZeroG^TM sessions requiring greater muscle activation. For SCI, muscle activation was higher in treadmill conditions compared to the ZeroG^TM due to increases in TA and BF activity. The Manual Treadmill and ZeroG^TM should be considered progressions following Lokomat^TM training where hip extension can be encouraged using the treadmill and additional components of gait (e.g. balance, torso stability) can be focused on using the ZeroG^TM.</p> / Master of Science (MS)

Depuis quelques années, de nouveaux systèmes de rééducation à la marche de type orthèse tels que le Lokomat® (Hocoma AG, Volketswil, Suisse) apparaissent dans les laboratoires de recherche clinique. Ces outils sont proposés, via des programmes de réentraînement à l’effort, pour la rééducation des patients présentant des altérations de l’appareil locomoteur. Leur but principal consiste à réacquérir une marche fonctionnelle grâce à une simulation des différentes phases de la marche et à une stimulation sensitive nourrissant les réafférences proprioceptives. Le Lokomat® permet donc, par une répétition prolongée des patrons de marche, un apprentissage sensori-moteur actif et progressif pour le patient. Les objectifs de notre étude sont : (1) de caractériser les processus de contrôle de l’équilibre (coordinations multi-segmentaires) pendant la marche chez des enfants atteints de paralysie cérébrale, comparativement à un groupe d’enfants à développement typique, en analysant les différentes stratégies mises en œuvre pour se propulser vers l’avant tout en préservant leur équilibre, puis (2) de mettre en évidence l’apport d’une rééducation robotisée à la marche dans l’amélioration et/ou la modification des paramètres biomécaniques de la marche chez des enfants atteints de paralysie cérébrale et d’en observer les influences éventuelles sur la motricité globale de l’enfant (nouvelles stratégies, amélioration du rapport coût/bénéfice, etc.). / In recent years, robotically driven orthoses such as the Lokomat® (Hocoma AG, Volketswil, Switzerland) appear in clinical research laboratories. These tools are proposed through gait training programs for the rehabilitation of patients with locomotor disorders. Their main purpose consists to reacquire functional gait through a simulation of the different phases of gait and a sensory stimulation feeding proprioceptive feedback. The Lokomat® allows by an extended repetition of gait patterns an active and progressive sensorimotor learning for the patient. The aims of our study are: (1) to characterize balance control processes (multisegmental coordination) in gait children with cerebral palsy compared to a group of typical development children by analyzing the different strategies involved to maintain forward motion while maintaining dynamic balance, then (2) to show the effects of robot-assisted rehabilitation in gait retraining and show this impacts upon the postural control of children with cerebral palsy (news strategies, ratio cost/benefit improvement, etc).

Persons suffering central nervous system damage, such as a stroke, coma patients, or individuals that have suffered damage to the spinal cord, brainstem, cerebellum, and motor cortex, sometimes develop an asymmetric walking pattern where one leg does not fully swing backward. This uneven gait hinders these individuals in properly and efficiently moving through everyday life. Previous research in humans and various animals has introduced a split belt treadmill to analyze possible rehabilitation, which can recreate a correct gait pattern by altering the speed of each track. Gait adaptation was achieved by having the split belt treadmill move each leg at a different velocity relative to the ground and thus forcing a symmetric gait. Test subjects‟ gait would adapt to the speeds and a normal gait pattern could be conditioned while on the split belt treadmill. However, after short trials, individuals were unable to neurologically store these feed-forward walking patterns once walking over ground. Also, test subjects would have difficulty adapting their learned walking gait over different walking environments. The gait enhancing mobile shoe (GEMS) makes it possible to adjust an asymmetric walking gait so that both legs move at a relatively symmetric speed over ground. It alters the wearers walking gait by forcing each foot backwards during the stance phase, operating solely by mechanical motion, transferring the wearer‟s downward force into a horizontal backwards motion. Recreating the split belt treadmill effect over ground by using the GEMS will potentially enable me to test the long term effects of a corrected gait, which is impossible using a split belt treadmill. A previous prototype of the GEMS [1] successfully generated a split belt treadmill walking pattern, but had various drawbacks, such as variable motion from step to step. My new design of this rehabilitation shoe promises to alter the user‟s gait as a split belt treadmill does, and to be mechanically stable operating without any external power sources. I designed and constructed a new motion controlled gait enhancing mobile shoe that improves the previous version‟s drawbacks. While mimicking the asymmetric gait motion experienced on a split-belt treadmill, this version of the GEMS has motion that is continuous, smooth, and regulated with on-board electronics. An interesting aspect of this new design is the Archimedean spiral wheel shape that redirects the wearer‟s downward force into a horizontal backward motion. The design is passive and does not utilize any motors and actuators. Its motion is only regulated by a small magnetic pthesis brake. Initial tests show the shoe operates as desired, but further experimentation is needed to evaluate the long-term after-effects.

Background: Following a stroke the ability to walk is often impaired due to compromised motor-control, muscle weakness and spasticity, resulting in deviations during gait. Ankle-foot orthoses (AFO) can be used for people with hemiparesis to improve stability during stance phase and clearance during swing phase. There has been much discussion whether AFOs have a positive effect during early rehabilitation post stroke (in this study defined as six weeks from the initial stroke onset).Objectives: The aim was to describe the level of involvement of Danish Certified Prosthetists and Orthotists (CPO) in early rehabilitation of stroke patients in Denmark, and to describe danish orthotists view on their involvement in early rehabilitation of stroke patients.Method: A cross-sectional survey, in form of a self-administered questionnaire, was conducted during March and April 2021 in Denmark. The survey was sent to Danish CPOs who were currently members of the Danish professional organization for prosthetists/orthotists. A total of 110 members received the questionnaire by e-mail, 80 of which were registered as certified. The questionnaire consisted of 43 items (of which a minimum of 26 questions needed answering) with mainly closed ended questions. Descriptive statistics were used for data analysis, with frequencies, percentage and summarizing tables.Results: The response rate was 31.25 % (n=25). The survey demonstrated that only few participants (n=3) were involved in early gait rehabilitation, stroke patients were seen as out-patients in orthotic clinics (92%, n=23), usually 4–6-month post stoke (44%, n=11) and often with a referral from another member of the multidisciplinary team (MDT) (56%, n=14). Danish CPOs believed that orthotic assessment was an essential part of gait re-education (80% n=20), and that the orthotist should be part of the early gait rehabilitation (88%, n=22). Most of the orthotists (72%, n=18) were confident in recommending a treatment plan including lower extremity orthosis and were confident in advising the multidisciplinary team (MDT) in the use of orthosis (80%, n=20).Conclusion: It is uncommon for danish CPOs to be involved in the early rehabilitation of stroke patients and the Danish CPOs often first meet the patient late in the rehabilitation process. The CPOs believe that they should be part of early gait rehabilitation and that orthotic assessment should be part of gait re-education.

Introdução: A disfunção da marcha é um dos maiores comprometimentos funcionais do paciente com a doença de Parkinson (DP). A estimulação cerebral profunda do núcleo subtalâmico tem mostrado melhora da marcha e equilíbrio. Esse efeito pode ser mantido e potencializado por programas de reabilitação motora específicos, como o treino em esteira sem e com suporte de peso corporal. No entanto, faltam estudos desses treinos em pacientes com a DP em uso desta estimulação. Objetivo: Comparar parâmetros cinemáticos lineares e angulares da marcha de pacientes com a DP em uso de estimulação cerebral profunda bilateral do núcleo subtalâmico, antes e após dois treinamentos: esteira sem e com suporte de peso corporal, associados à cinesioterapia convencional. Métodos: 12 pacientes (60,9 ± 10,6 anos; 20 ± 7 anos de doença e 20 ± 4 meses de tempo de cirurgia) completaram ambos os treinos em estudo cruzado fixo. Os pacientes passaram por 8 semanas de treino de marcha em esteira sem suporte de peso corporal e programa de cinesioterapia convencional, seguidas por 6 semanas de período sem intervenção. Posteriormente, realizaram 8 semanas de treino de marcha em esteira com suporte de peso corporal e o mesmo programa de cinesioterapia regular. As intervenções tiveram frequência de duas vezes por semana e duração de 90 minutos por sessão. A análise cinemática da marcha envolveu oito câmeras infravermelhas que detectaram 19 marcadores reflexivos nos membros inferiores dos pacientes. A análise estatística utilizou o teste Wilcoxon e foi adotado valor de p <= 0,05 como estatisticamente significante. Resultados: Ambos os treinos não mostraram diferenças significativas nos parâmetros lineares. Após o treino com suporte, observou-se aumento significativo dos seguintes parâmetros angulares: amplitude de movimento da pelve (inclinação, obliquidade e rotação); amplitude de movimento do quadril (abduçãoadução e rotação); % da fase de balanço que corresponde à flexão máxima do joelho e amplitude de movimento da progressão do pé. Conclusão: O treino em esteira com suporte de peso corporal mostrou capacidade de promover mudanças em parâmetros cinemáticos angulares da marcha. As implicações do treino em suspensão podem ter sido somadas aos efeitos neurofisiológicos da estimulação cerebral profunda e então desencadeado a melhora da mobilidade dos membros inferiores durante a marcha / Introduction: Gait disturbance is one of the hallmark features of Parkinson\'s disease (PD). Subthalamic nucleus deep brain stimulation (DBS) has shown improvements in gait and balance, and this effect can be maintained and enhanced by specific motor rehabilitation programs, such treadmill training without and with body weight support. However, at present there is a paucity of research on these combined interventions in PD with of this stimulation. Objective: To compare training-induced changes in gait linear and angular kinematic parameters among patients with PD who have used bilateral subthalamic nucleus DBS, and a combined intervention of conventional physical therapy with either treadmill training with body weight support or without support. Methods: 12 patients (age: 60.9 ± 10.6 years; disease duration: 20 ± 7 years; and time since DBS surgery: 20 ± 4 months) completed both training protocols in a fixed cross-over design. All patients received 8 weeks of treadmill training without body weight support in conjunction with conventional physical therapy, followed by a 6 weeks wash out period of no training. Thereafter, all patients received 8 weeks of body weight support treadmill training, in conjunction with the same conventional physical therapy. Both interventions had a frequency of two times per week, and duration of 90 minutes per session. Gait kinematic analysis involved eight infrared cameras that detected 19 reflective spherical markers attached to the limb lower of patients. Statistical analysis used the Wilcoxon and was adopted the value of p <= 0,05 as statistically significant. Results: Both the training no showed significant differences in linear parameters. After the body weight support training, observed there was a significant increase in following angular parameters: pelvis\' range of motion (tilt, obliquity, rotation); hip\'s range of motion (abduction-adduction and rotation); % Knee maximal flexion on Swing phase and foot progression\' range of motion. Conclusion: Treadmill training with body weight support showed an ability to promote changes in gait angular kinematic parameters. The implications of this training may have been added to the neurophysiological effects of DBS and then triggered the improved of mobility of lower limbs during gait

Introdução: A disfunção da marcha é um dos maiores comprometimentos funcionais do paciente com a doença de Parkinson (DP). A estimulação cerebral profunda do núcleo subtalâmico tem mostrado melhora da marcha e equilíbrio. Esse efeito pode ser mantido e potencializado por programas de reabilitação motora específicos, como o treino em esteira sem e com suporte de peso corporal. No entanto, faltam estudos desses treinos em pacientes com a DP em uso desta estimulação. Objetivo: Comparar parâmetros cinemáticos lineares e angulares da marcha de pacientes com a DP em uso de estimulação cerebral profunda bilateral do núcleo subtalâmico, antes e após dois treinamentos: esteira sem e com suporte de peso corporal, associados à cinesioterapia convencional. Métodos: 12 pacientes (60,9 ± 10,6 anos; 20 ± 7 anos de doença e 20 ± 4 meses de tempo de cirurgia) completaram ambos os treinos em estudo cruzado fixo. Os pacientes passaram por 8 semanas de treino de marcha em esteira sem suporte de peso corporal e programa de cinesioterapia convencional, seguidas por 6 semanas de período sem intervenção. Posteriormente, realizaram 8 semanas de treino de marcha em esteira com suporte de peso corporal e o mesmo programa de cinesioterapia regular. As intervenções tiveram frequência de duas vezes por semana e duração de 90 minutos por sessão. A análise cinemática da marcha envolveu oito câmeras infravermelhas que detectaram 19 marcadores reflexivos nos membros inferiores dos pacientes. A análise estatística utilizou o teste Wilcoxon e foi adotado valor de p <= 0,05 como estatisticamente significante. Resultados: Ambos os treinos não mostraram diferenças significativas nos parâmetros lineares. Após o treino com suporte, observou-se aumento significativo dos seguintes parâmetros angulares: amplitude de movimento da pelve (inclinação, obliquidade e rotação); amplitude de movimento do quadril (abduçãoadução e rotação); % da fase de balanço que corresponde à flexão máxima do joelho e amplitude de movimento da progressão do pé. Conclusão: O treino em esteira com suporte de peso corporal mostrou capacidade de promover mudanças em parâmetros cinemáticos angulares da marcha. As implicações do treino em suspensão podem ter sido somadas aos efeitos neurofisiológicos da estimulação cerebral profunda e então desencadeado a melhora da mobilidade dos membros inferiores durante a marcha / Introduction: Gait disturbance is one of the hallmark features of Parkinson\'s disease (PD). Subthalamic nucleus deep brain stimulation (DBS) has shown improvements in gait and balance, and this effect can be maintained and enhanced by specific motor rehabilitation programs, such treadmill training without and with body weight support. However, at present there is a paucity of research on these combined interventions in PD with of this stimulation. Objective: To compare training-induced changes in gait linear and angular kinematic parameters among patients with PD who have used bilateral subthalamic nucleus DBS, and a combined intervention of conventional physical therapy with either treadmill training with body weight support or without support. Methods: 12 patients (age: 60.9 ± 10.6 years; disease duration: 20 ± 7 years; and time since DBS surgery: 20 ± 4 months) completed both training protocols in a fixed cross-over design. All patients received 8 weeks of treadmill training without body weight support in conjunction with conventional physical therapy, followed by a 6 weeks wash out period of no training. Thereafter, all patients received 8 weeks of body weight support treadmill training, in conjunction with the same conventional physical therapy. Both interventions had a frequency of two times per week, and duration of 90 minutes per session. Gait kinematic analysis involved eight infrared cameras that detected 19 reflective spherical markers attached to the limb lower of patients. Statistical analysis used the Wilcoxon and was adopted the value of p <= 0,05 as statistically significant. Results: Both the training no showed significant differences in linear parameters. After the body weight support training, observed there was a significant increase in following angular parameters: pelvis\' range of motion (tilt, obliquity, rotation); hip\'s range of motion (abduction-adduction and rotation); % Knee maximal flexion on Swing phase and foot progression\' range of motion. Conclusion: Treadmill training with body weight support showed an ability to promote changes in gait angular kinematic parameters. The implications of this training may have been added to the neurophysiological effects of DBS and then triggered the improved of mobility of lower limbs during gait