Providing patients with a leg prosthesis or a (knee) ankle foot orthosis requires an estimated guess about the effects of the prosthesis/orthosis on gait. Mostly we observe and interpret gait. For a proper gait observation, knowledge of normal gait and gait biomechanics is essential. Also, by just observing gait, we can get no information about the forces and joint moments and, therefore, a proper alignment is very difficult to perform. This contribution will focus on some basics of gait, some basics of gait biomechanics, possibilities with instrumented Gait Analysis and some examples of interventions with their biomechanical effects.
The purpose of this study was to investigate the gait pattern effects on gait exercises using the walking assist device ACSIVE. Experiments 1 and 2 were both intended for twenty healthy subjects. Experiment 1 compared the effects on the gait pattern between barefoot walking and walking with ACSIVE. In Experiment 2, the purpose was to compare the effects on the gait pattern between barefoot walking and walking with ACSIVE after gait exercises. Their walking was measured using an optoelectronic motion capture system with ten infrared cameras (VICON612) and a ground reaction force platform (AMTI : OR6-6). Kinetics data were calculated using the inverse-dynamics method. As a result, assist by ACSIVE affected the terminal stance from the loading response phase of the hip and knee joints. Further, after the walking exercises with ACSIVE, in hip moment, the maximum extension moment of loading response phase and mid-stance was increased, which reduced the maximum flexion moment.
Pulmonary embolism accompanying deep vein thrombosis (economy-class syndrome), can develop in individuals who must sit for long periods, for example, during air travel or after earthquakes. The present study investigated the ability of portable pressurization slippers to prevent thrombosis. Peak blood velocity (PBV) in the popliteal vein was measured in ten healthy adults (male, n=4) using pulse-duplex ultrasonography. The mean PBV for the group that lightly stamped their feet in a seated position while wearing the pressurization slippers was 2.6-fold higher than that for the group that did not wear the slippers, and was about 22-fold higher than that for the group that rested barefoot. Thus, stamping while wearing the portable pressurization slippers increases PBV and can be expected as one of the prophylactic measure to decrease the risk of economy-class syndrome.
Knee-Ankle-Foot Orthoses (KAFOs) are commonly used for the gait training of stroke patients with severe paralysis. However, the deterioration of gait is frequently found when the KAFOs are changed to Ankle-Foot Orthoses (AFOs). The gait of a stroke patient who showed a significant gait change with both orthoses was measured by a 3D motion analysis system. The gait with the KAFO looked good by visual observation ; however, the hip extension moment was not found in loading response of the paretic limb. When the patient walked with the AFO the hip extension moment was found in mid stance instead of the loading response, and the smooth progression of the center of gravity was disturbed. It is important to consider timing of the muscle activity in the process of gait training with KAFOs.