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Hip abduction orthosis devices (HAOD) are used to reduce the hip joint of infants affected by developmental dysplasia of the hip (DDH). HAOD have been successful for mild cases of DDH and ineffective for severe cases. Efforts in understanding the biomechanics of lower limbs have been made to improve the success rate of current treatment methods, especially for Grade IV dislocations (G4). The aim of this dissertation is twofold: first, it proposes the use of a varying fulcrum point (FP) located below the leg to improve DDH treatment; and secondly, it defines the optimal FP (OP) location for a broad spectrum of hip joint configurations. An iterative 3D computational model of a 10-week-old infant was developed using parameters of the femur, pelvis, and lower limb muscles along with their anatomical location. The computational model provides a variety of scenarios of closed reduction and the location of the OP, which is believed to be a key parameter for a successful reduction in severe cases of DDH. The problem is posed as a maximization of an objective function whose independent parameter is the location of the FP constrained to vary over an anatomically feasible range along the femur. For each location of the FP, the model computes resultant forces and evaluates a potential energy function. The OP maximizes the projection of the resultant vector force of the femur over the least energy path to assist in achieving G4 reduction. The results of this study suggest that for the range of the parameters used in the model, G4 reduction can be achieved as the FP reaches the femoral head with the aid of additional external traction forces. Results from this study may be used to customize current orthosis design by using patient-specific parameters, which can be obtained from imaging.

Objective: To gather knowledge related to patient satisfaction and mobility with lower limb prosthetic and orthotic devices and to investigate satisfaction with services received. Another purpose of this study is to analyze potential differences between orthotic and prosthetic patients in relation to patient satisfaction and mobility. Design: Cross-sectional study Subjects: 21 participants with a mean age of 58 (SD 16) with an average duration of use of devices of 10 (SD 10) years. 12 out of the 21 participants were orthotic users and 9 were prosthetic users. Methods: Patients were asked to complete two questionnaires, one regarding satisfaction with assistive device and service (QUEST 2.0) and one regarding mobility. Results: Patients mean score regarding satisfaction with assistive device and service were 4.0 (SD 0.8) and 4.2 (SD 1.0) respectively. 91% reported that they had the ability to walk at least 100 meters with their assistive device. The areas where participants experienced most difficulties were walking on uneven ground (70%), walking up and down a hill (57%) and walking on stairs (57%). Conclusion: Overall this study demonstrates that participants were quite satisfied with their assistive device and the service received by the P&O clinic. No statistically significant differences regarding satisfaction with assistive device and service, or mobility, were found between prosthetic and orthotic participants.

The electromyogram (EMG) signal is desired to be used as a control signal for applications such as multifunction prostheses, wheelchair navigation, gait generation, grasping control, virtual keyboards, and gesture-based interfaces [25]. Several research studies have attempted to relate the electromyogram (EMG) activity of the forearm muscles to the mechanical activity of the wrist, hand and/or fingers [41], [42], [43]. A primary interest is for EMG control of powered upper-limb prostheses and rehabilitation orthotics. Existing commercial EMG-controlled devices are limited to rudimentary control capabilities of either discrete states (e.g. hand close/open), or one degree of freedom proportional control [4], [36]. Classification schemes for discriminating between hand/wrist functions and individual finger movements have demonstrated accuracy up to 95% [38], [39], [29]. These methods may provide for increased amputee function, though continuous control of movement is not generally achieved. This thesis considered proportional control via EMG-based estimation of finger forces with the goal of identifying whether multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm. Electromyogram (EMG) activity from the extensor and flexor muscles of the forearm was sensed with bipolar surface electrodes and related to the force produced at the four fingertips during constant-posture, slowly force-varying contractions from 20 healthy subjects. The contractions ranged between 30% maximum voluntary contractions (MVC) extension and 30% MVC flexion. EMG amplitude sampling rate, least squares regularization, linear vs. nonlinear models and number of electrodes used in the system identification were studied. Results are supportive that multiple degrees of freedom of proportional control information are available from the surface EMG of the forearm, at least in healthy subjects. An EMG amplitude sampling frequency of 4.096 Hz was found to produce models which allowed for good EMG amplitude estimates. Least squares regularization with a pseudo-inverse tolerance of 0.055 resulted in significant improvement in modeling results, with an average error of 4.69% MVC-6.59% MVC (maximum voluntary contraction). Increasing polynomial order did not significantly improve modeling results. Results from smaller electrode arrays remained fairly good with as few as six electrodes, with the average %MVC error ranging from 5.13%-7.01% across the four fingers. This study also identified challenges in the current experimental study design and subsequent system identification when EMG-force modeling is performed with four fingers simultaneously. Methods to compensate for these issues have been proposed in this thesis.

Este trabalho consiste no projeto mecânico de um exoesqueleto robótico para paraplégicos com lesões medulares entre T2 a L1, ou seja, sem mobilidade da cintura para baixo e com mobilidade do peito para cima, inclusive das mãos. A utilização do equipamento necessita da utilização de muletas ou andadores. O mecanismo possui seis graus de liberdade, sendo quatro atuados por motorredutores (joelhos e quadris) e dois suportados por molas (tornozelos). Os motorredutores são projetados especialmente para o exoesqueleto, sendo compostos de um motor de corrente continua de imã permanente e um redutor harmônico do tipo panqueca acoplados de forma adequada para minimizar peso e volume. Para calcular os esforços solicitados em cada articulação foi desenvolvido um modelo dinâmico do corpo humano para simular os movimentos que o exoesqueleto é capaz de realizar, que são: marchar, sentar, levantar e subir e descer escadas. O modelo utilizado do corpo humano possui cinco ligamentos rígidos e é capaz de simular movimentos no plano vertical. Os resultados obtidos da simulação são comparados com resultados experimentais da literatura e são considerados satisfatórios. / This work presents a mechanical design of a robotic exoskeleton for paraplegics with spinal cord injuries between T2 to L1, that means, without mobility from the waist down and with mobility from the chest up, including the hands. For using the equipment the paraplegic needs the aid of crutches or walkers. The mechanism has six degrees of freedom, with four degrees actuated by gear motors (knees and hips), and two degrees supported by springs (ankles). The gear motors are designed especially for the exoskeleton. They are composed by an permanent magnet brushless electric motor conveniently coupled with an pancake harmonic speed reducer to minimize weight and volume. For calculating the efforts in each joint a model for the human body is developed to simulate the movements the exoskeleton can perform, which are: walk, sit, standup and climb up and down stairs. The human body model has five rigid links and it is capable to simulate movements in the vertical plane. The results obtained in the simulations are compared very well with experimental results from the literature.

This thesis provided the foundational work for a low-cost three-dimensional (3D) printed custom knee brace. Specifically, the objective was to research, develop and implement a novel workflow aimed to be easy to use and available to anyone who has access to a smartphone camera and 3D printing services. The developed workflow was used to manufacture two prototypes which proved valuable in the design iterations. As a result, an improved hinge was designed which has increased mechanical strength. Additionally, a smartphone photogrammetry validation study was included which provided preliminary results on the accuracy and precision. This novel measurement method has the potential to require little training and could be disseminated through video instructions posted online. The intention is to enable the patient to collect their own “3D scan” with the help of a friend or family member, effectively removing the need to book an appointment simply for collecting custom measurements. Lastly, it would allow the clinician to focus all their time on clinically relevant design tasks such as checking alignment, fit and comfort, which could all potentially be improved by adopting such digital methods. The ultimate vision for this work is to enable manufacturing of better custom knee braces at a reduce cost which are easily accessible for low-income populations.

Este trabalho consiste no projeto mecânico de um exoesqueleto robótico para paraplégicos com lesões medulares entre T2 a L1, ou seja, sem mobilidade da cintura para baixo e com mobilidade do peito para cima, inclusive das mãos. A utilização do equipamento necessita da utilização de muletas ou andadores. O mecanismo possui seis graus de liberdade, sendo quatro atuados por motorredutores (joelhos e quadris) e dois suportados por molas (tornozelos). Os motorredutores são projetados especialmente para o exoesqueleto, sendo compostos de um motor de corrente continua de imã permanente e um redutor harmônico do tipo panqueca acoplados de forma adequada para minimizar peso e volume. Para calcular os esforços solicitados em cada articulação foi desenvolvido um modelo dinâmico do corpo humano para simular os movimentos que o exoesqueleto é capaz de realizar, que são: marchar, sentar, levantar e subir e descer escadas. O modelo utilizado do corpo humano possui cinco ligamentos rígidos e é capaz de simular movimentos no plano vertical. Os resultados obtidos da simulação são comparados com resultados experimentais da literatura e são considerados satisfatórios. / This work presents a mechanical design of a robotic exoskeleton for paraplegics with spinal cord injuries between T2 to L1, that means, without mobility from the waist down and with mobility from the chest up, including the hands. For using the equipment the paraplegic needs the aid of crutches or walkers. The mechanism has six degrees of freedom, with four degrees actuated by gear motors (knees and hips), and two degrees supported by springs (ankles). The gear motors are designed especially for the exoskeleton. They are composed by an permanent magnet brushless electric motor conveniently coupled with an pancake harmonic speed reducer to minimize weight and volume. For calculating the efforts in each joint a model for the human body is developed to simulate the movements the exoskeleton can perform, which are: walk, sit, standup and climb up and down stairs. The human body model has five rigid links and it is capable to simulate movements in the vertical plane. The results obtained in the simulations are compared very well with experimental results from the literature.

This position paper outlines the important role of academia in shaping the orthotics and prosthetics (O&P) profession and preparing for its future. In the United States, most healthcare professions including O&P are under intense pressure to provide cost effective treatments and quantifiable health outcomes. Pivotal changes are needed in the way O&P services are provided to remain competitive. This will require the integration of new technologies and data driven processes that have the potential to streamline workflows, reduce errors and inform new methods of clinical care and device manufacturing. Academia can lead this change, starting with a restructuring in academic program curricula that will enable the next generation of professionals to cope with multiple demands such as the provision of services for an increasing number of patients by a relatively small workforce of certified practitioners delivering these services at a reduced cost, with the expectation of significant, meaningful, and measurable value. Key curricular changes will require replacing traditional labor-intensive and inefficient fabrication methods with the integration of newer technologies (i.e., digital shape capture, digital modeling/rectification and additive manufacturing). Improving manufacturing efficiencies will allow greater curricular emphasis on clinical training and education - an area that has traditionally been underemphasized. Providing more curricular emphasis on holistic patient care approaches that utilize systematic and evidence-based methods in patient assessment, treatment planning, dosage of O&P technology use, and measurement of patient outcomes is imminent. Strengthening O&P professionals' clinical decision-making skills and decreasing labor-intensive technical fabrication aspects of the curriculum will be critical in moving toward a digital and technology-centric practice model that will enable future practitioners to adapt and survive.

This thesis presents an engineering approach to the modeling and analysis of custom foot orthotics. Although orthotics are widely used and accepted as devices for the prevention of and recovery from injuries, the design process continues to be based on empirical means. There have been many clinical studies investigating the various effects that the orthotics can have on the kinematics and kinetics of human locomotion. The results from these studies are not always consistent, primarily due to subject variability and experimental nature of the design. Alternatively, a better understanding of the therapeutic effects of custom foot orthotics, as well as designing for optimal performance, can be achieved through simulation-based engineering modeling and analysis studies. Such an approach will pave the way to clarify some of the ambiguous findings found in the clinical studies-based literature. Towards this goal, this research presents a methodical process for the replication of the orthotics’ complex three-dimensional geometry and for the construction of finite element analysis models using estimated nonlinear material properties. As part of this research, laser scanning techniques are used to capture the objects’ details and geometry through generation of point cloud surface images by taking multiple scans from all angles. Material testing and Mooney-Rivlin equations were used to construct the hyperelastic nonlinear material properties. Using the mid-stance phase of gait for loading conditions, the ANSYS finite element package was utilized to run analyses on three different load classifications and the corresponding maximum stresses and deflection results were generated. The results indicate that the simulated models can augment and validate the use of empirical tables for designing custom foot orthotics. They can also provide the basis for the optimal design thicknesses of custom foot orthotics based on an end-users’ weight and activities. From a practical perspective, they can also be useful in further exploring different orthotics, loading conditions, material properties, as well as the effectiveness of orthotics for different foot and lower extremity deformities.

Yes / Background: When trans-tibial amputees cross obstacles leading with their prosthesis, foot clearance is achieved using compensatory swing-phase kinematics. Such compensation would suggest able-bodied individuals normally use swing-phase ankle dorsiflexion to attain adequate obstacle clearance, however, direct evidence of such contribution is equivocal. The present study determined the contribution of sagittal plane ankle motion in achieving lead-limb clearance during obstacle negotiation. Methods: 12 male able-bodied individuals (ages 18-30) completed obstacle crossing trials while walking on a flat surface. Lead-limb (right) ankle motion was manipulated using a knee-ankle-foot orthosis. Trials were completed with the ankle restricted at a neutral angle or unrestricted (allowing ~ ±15  plantar/dorsiflexion). Findings: Restricted ankle motion caused significant increase in trail-limb foot placement distance before the obstacle (p=0.005); significant decrease in vertical toe clearance (p<0.003), vertical heel clearance (p=0.045) and lead-limb foot placement distance after the obstacle (p=0.045); but no significant changes in knee angle at instant of crossing or in average walking speed. Interpretation: The shifts in foot placements altered the part of swing that the lead-limb was in when the foot crossed the obstacle, which led to a decrease in clearance. These adaptations may have been due to being unable to dorsiflex the ankle to ‘lift’ the toes in mid-swing or to being unable to plantarflex the ankle during initial contact following crossing, which changed how the lead-limb was to be loaded. These findings suggest individuals using ankle bracing or those with ankle arthrodesis, will have reduced gait safety when negotiating obstacles.