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With progress of modern technology, manually-propelled wheelchairs are still of importance for individuals with mobility impairments. The repeated wheelchair propulsion and strenuous daily activities cause high loads and thus injuries on the upper extremity joints. Over the past few years, a considerable number of studies have been made on biomechanical analysis of wheelchair propulsion and wheelchair-related activities. Thorough investigation of biomechanics during wheelchair propulsion enhances comprehension of mechanism of injuries and provides information to improve wheelchair design and fitting. Numerous investigations have been made to demonstrate factors which cause low effectiveness of force application and inefficiency of movements. Emphasis was also placed on developing analytical models to simulate wheelchair propulsion.

This study examined chronic, isolated posterior cruciate ligament (PCL) rupture patients, dividing them into symptomatic and asymptomatic groups according to whether they displayed obvious symptoms in daily activities. Each group comprised 10 patients while 10 healthy, young individuals were adopted as the control group. Using a three-dimensional motion analysis system and force plates, the gait patterns of the PCL-deficient patients were analyzed from both kinematics and kinetics perspectives to identify whether they differed from the control group and to compare symmetry between the injured and uninjured sides. The results showed that the symptomatic PCL-deficient group was closer to "normal", and the asymptomatic PCL-deficient group showed less knee extension moment and lower power absorption in the terminal stance than the control group. Additionally, the symptomatic PCL-deficient group appeared to have a relatively symmetric gait while the asymptomatic PCL-deficient group primarily showed an asymmetric gait also occurring in the terminal stance, including less joint moment and lower power absorption of the hip and knee, and lower vertical ground reaction force (GRF). Regarding the gait adaptations of the asymptomatic PCL-deficient group these compensation mechanisms are most likely to have been produced in order to assist in joint stabilization and reduce symptoms in joints.

Slips and falls often occur in the industrial environments. They are not only caused by environmental hazards but also by some biomechanical factors related to deficient ability of postural control to arrest impending falls. The purpose of this study is to simulate the slip condition in human walking and to find out the possible related factors of biomechanics.

Eleven male and 9 female recruited were healthful without any musculoskeletal and neurological impairments. In order to provide different disturbance level, three lean angles of tilting boards were designed as 10, 20, 30 degrees with respect to horizontal plane. Subjects wore a safety harness, stood on the tilting board and were released without awareness. A forceplate applied a soap patch was in front of the tilting board to serve the slippery perturbation and to measure the fool/floor reactions. Movements of body segments were measured using the motion analysis system.

The results were shown that lean angle had a significant effect to all parameters except step length, response time, maximum ankle forward velocity, hip forward velocity, and ankle flex angle. The gender significantly affected on the step length, response time, maximum ankle forward velocity, and knee forward velocity. Larger lean angle made subjects to take a more rapid step. In order to absorb the shock in foot strike, subjects flexed more their knee and increased the foot landing angle in larger lean angle. Male tended to adopt the long step-length strategy to respond to the slippery perturbation and female tended to use the short step-length strategy instead. The results of maximum ankle forward velocity suggested that short step-length strategy could be belter to reduce the foot slip than long step-length strategy.

This study scientifically measures the dynamic gait characteristics and energy cost of six male below-knee amputees, three vascular and three traumatic, while wearing SACH, single axis and multiple axis prosthetic feet via six-camera motion analysis, metabolic measurement cart and heavy-duty treadmill. Subjective results are additionally determined via questionnaire after testing. Motion analysis showed statistically significant differences at p < 0.05 between the solid ankle cushion heel (SACH), single axis and multiple axis foot in the velocity, cadence, stride length end gait cycle. Significant differences were found in energy cost among the prosthetic feet tested, and significant changes in walking under different speeds and different inclines. Results provide quantitative and qualitative information about the dynamic performance of the various feet which can be helpful in prescribing the optimal prosthetic foot for individual amputees.