Although footwear has been recognised as a risk factor for falls in older people, it remains unclear as to which features of shoes are beneficial or detrimental to balance. This project aimed to systematically investigate the effects of common shoe features, namely: an elevated heel, a soft sole, a hard sole, a flared sole, a bevelled heel, a high-collar and a tread sole, on balance and gait in older community-dwelling people. The experimental shoes were compared to standard shoes in three studies examining: (i) standing balance, leaning balance and stepping in 29 older people, (ii) centre of mass (COM)-base of support (BOS) margins, vertical and braking loading rates, and perceived shoe comfort and stability in 11 young and 15 older people walking on even and uneven surfaces, and (iii) temporal-spatial gait variables, pelvis acceleration, and gait termination in 10 young and 26 older people, on level, irregular and wet surfaces. Elevated heel shoes impaired overall performance in functional tests of balance and stepping. They were also perceived as lacking comfort and stability and led to a conservative walking pattern characterised by increased step width and double-support time, reduced braking and vertical loading rates and medio-lateral (ML) pelvis accelerations on various surfaces. Soft sole shoes increased lateral COM-BOS margin and step width, indicating reduced ML walking stability. When wearing these shoes, subjects had longer total stopping times and on the wet surface, smaller step lengths and shoe/floor angles at heel strike, suggesting a potential risk of slipping. When wearing high-collar shoes, subjects had better balance as demonstrated by small but significant increases in lateral COM-BOS margin, double-support time and step width, and decreases in ML pelvis accelerations on varying surfaces and in total stopping time on the wet surface. Shoes with hard, flared or tread soles or a bevelled heel did not affect balance. In conclusion, providing that they are fitted, have adequate fastening and perhaps a slip-resistant sole, shoes with a low square heel, a sole of medium hardness (shore A-40) and a high-collar provide the greatest stability for older people when walking on dry, wet and irregular surfaces.

Thesis (Ph. D.)--University of Sydney, 2006. / Title from title screen (viewed 12 February 2009). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Medicine, Faculty of Medicine. Includes bibliographical references. Also available in print form.

Thesis (Ph. D.)--University of Oregon, 2008. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 88-96). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Thesis (M.S.)--University of Oregon, 2004. / Includes bibliographical references (leaves 56-58). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

Thesis (M.S.)--University of Oregon, 2004. / Includes bibliographical references (leaves 56-58).

Thesis (Ph. D.)--University of Oregon, 2002. / Includes bibliographical references (leaves 178-188).

Thesis (Ph.D)--University of Oregon, 2005. / Includes bibliographical references (leaves 94-101)

M.Tech. (Chiropractic) / Purpose: The pelvis, femur, tibia, fibula, ankle and foot form a closed kinematic chain during gait. According to biomechanical principles any restriction or tension in one part of the kinematic chain will create increased load on the other parts of the same chain (Comerford and Mottram, 2001; Sahrmann, 2000). This increased load can lead to dysfunction and compensation along the chain and also lead to gait anomalies. A chiropractic adjustment is utilised for the treatment of sacroiliac joint restrictions. There has not been research conducted to establish the effects that a chiropractic adjustment has on lower limb biomechanics and gait. The purpose of this study was to determine whether a sacroiliac adjustment had an effect on gait by looking at the gait parameters. Method: Sixty participants who were between the ages of 18 and 40 years were recruited. The participants were asked to sign a consent form and then a thorough history and physical examination was performed to ensure that participants did not have any disease or pathology that may have excluded them from the study. These included foot pathologies, knee pathologies, hip pathologies, structural leg length discrepancies, or any contraindications to chiropractic adjustment. A lumbar spine regional examination as well as motion palpation of the sacroiliac joints was performed to determine which joints were restricted. Each participant then underwent a gait assessment before and after they received a chiropractic adjustment to the restricted sacroiliac joint. Procedure: Participants only received one adjustment. Objective measurements were obtained using the Zebris FDM gait analysis system. This system uses high-quality capacitive force sensors that are arranged in matrix form. As a result, each sensor produces its own calibration curve. The measuring plates enable the static and dynamic force distribution to be analysed under the feet while standing and walking. The measuring plate is integrated in a level walking area. The measuring parameters are automatically calculated in the WinFDM program and a printable, easy to read report of the measuring results is then available (Zebris Medical GmbH, Germany). Each participant walked over the measuring plate for 4 times. This was done before and after the adjustment.Results: Statistically significant changes were seen between the pre and post treatment measurements of foot rotation on the treatment side, the step length on the treatment side, the stride length, the stance phase on both the treatment and non-treatment sides, the swing phase on the treatment and non-treatment side and the total double support. Conclusion: This study shows that a chiropractic adjustment to the sacroiliac joint does change certain gait parameters and it should therefore be part of any treatment regime for gait abnormalities. Podiatrists, biokineticists and chiropractors should work together when treating patients with gait abnormalities. As the study only recruited asymptomatic participants, further studies are necessary to determine the effect a chiropractic adjustment has on the gait of symptomatic patients.

The purpose of this study was to examine the kinematics of the pelvis and the right hip and the electromyographic activity of the gluteus maximus and biceps femoris during backward walking in children with spastic diplegic cerebral palsy and children without known disabilities. Subjects included 6 children, three with a diagnosis of spastic diplegia and three without known disabilities. The results of the study showed important differences between the experimental group and the control group. Subjects with spastic diplegic cerebral palsy (SDCP) walked backwards with less hip extension, more body rotation, shorter and slower steps, and used a higher percentage of their maximum voluntary contraction than the control group. No significant differences were found between both groups in the total amount of hip sagittal range of motion; however, these motions occurred towards flexion in the group of children with spastic diplegic cerebral palsy and towards neutral and extension in the control group. Independent backward walking seems not to be an effective way to promote active hip extension in children with spastic diplegic cerebral palsy. Clinicians using backward walking in therapeutic programs may benefit from this data.

The primary goal of human locomotion is to stably translate the center of mass (CoM) over the ground with minimum expenditure of energy. Pelvic movement is crucial for walking because the human CoM is located close to the pelvic center. Because of this anatomical feature, pelvic motion directly contributes to the metabolic expenditure, as well as in the balance to keep the center of mass between the legs. An abnormal pelvic motion during the gait not only causes overexertion, but also adversely affects the motion of the trunk and lower limbs. In order to study different interventions, recently a cable-actuated robotic system called Tethered Pelvic Assist Device (TPAD) was developed at ROAR laboratory at Columbia University. The cable-actuated system has a distinct advantage of applying three dimensional forces on the pelvis at discrete points in the gait cycle in contrast to rigid exoskeletons that restrict natural pelvic motion and add extra inertia from the rigid linkages. However, in order to effectively use TPAD for rehabilitation purposes, we still need to have a better understanding of how human gait is affected by different forces applied by TPAD on the pelvis. In the present dissertation, three different control methodologies for TPAD are discussed by performing human experiments with healthy subjects and patients with gait deficits. Moreover, the corresponding changes in the biomechanics during TPAD training are studied to understand how TPAD mechanistically influences the quality of the human gait. In Chapter 2, an ‘assist-as-needed’ controller is implemented to guide and correct the pelvic motion in three dimensions. Here, TPAD applies the correction force based on the deviation of the current position of the pelvic center from a pre-defined target trajectory. This force acts on the pelvic center to guide it towards the target trajectory. A subject in the device experiences a force field, where the magnitude becomes larger when the subject deviates further away from the target trajectory. This control strategy is tested by performing the experiments on healthy subjects with different target pelvic trajectories. Chapter 3 describes a robotic resistive training study using a continuous force on the pelvis to strengthen the weak limbs so that subjects can improve their walking. This study is designed to improve the abnormal gait of children with Cerebral Palsy (CP) who have a crouch gait. Crouch gait is caused by a combination of weak extensor muscles that do not produce adequate muscle forces to keep the posture upright, coupled with contraction of muscles that limit the joint range of motion. Among the extensor muscles, the soleus muscle acts as the major weight-bearing muscle to prevent the knees from collapsing forward during the middle of the stance phase when the foot is on the ground. Electromyography, kinematics, and clinical measurements of the patients with crouch gait show significant improvements in the gait quality after the resistive TPAD training performed over five weeks. Both Chapters 2 & 3 present interventions that are bilaterally applied on both legs. Chapter 4 introduces a training strategy that can be used for patients who have impairments in only one leg which results in manifests as asymmetric weight-bearing while walking. This training method is designed to improve the asymmetric weight bearing of the hemiparetic patients who overly rely on the stronger leg. The feasibility of this training method is tested by experiments with healthy subjects, where the controller creates an asymmetric force field to bring asymmetry in weight bearing during walking. In summary, the present dissertation is devoted to developing new training methods that utilize TPAD for rehabilitation purposes and characterize the responses of different force interventions by investigating the resulting biomechanics. We believe that these methodologies with TPAD can be used to improve abnormal gait patterns that are often observed in cerebral palsy or stroke patients.