Browsing by Author "Yang, B. -S."

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Effects of Floor Material Change on Gait Stability
(2009)
Yang, B. -S.
;
Hu, H. -Y.
;
機械工程學系
;
Department of Mechanical Engineering
Falls are the leading cause of unintentional injuries in the elderly in Taiwan and many industrial countries, and commonly occur at home. To reduced fall-related socioeconomic cost, the goal of this study is to identify suitable floor materials on which the elderly could have stable gait. We tried to quantify the gait stability under different floor conditions in this paper. Six healthy subjects (aged 20-23 yrs) have been tested. A six-camera motion capture system and two force platforms were used to obtain kinematics and kinetics of whole body during gait on different floor conditions. In consistent conditions (same floor materials on the whole walkway), the lower the coefficient of friction (COF) of the floor material, the smaller values of cadence and required COF (RCOF) under subjects' feet, and the larger values of gait stability-related variables, such as stance time, stride time, and step width, during walking at self-selected comfortable speed (p<0.05). As compared with the consistent conditions, walking from a material with higher COF to another with lower COF would induce larger ankle dorsi/plantar-flexion angle at heel contact. In addition, the peak RCOF during the stance phase was higher after the floor material change. The results of this study suggest that double support time, stride velocity, and mean gait velocity might be good indicators of gait stability. Walking from one floor material to another with lower COF may induce higher risk of falls than walking on a floor with consistent materials. Therefore, avoiding or using caution, especially for the elderly, when walking from one floor material to another with lower-COF is suggested.
Effects of Muscle Vibration on Independent Finger Movements
(2009)
Yang, B. -S.
;
Chen, S. -J.
;
機械工程學系
;
Department of Mechanical Engineering
Previous studies had demonstrated that small amplitude muscle vibration (MV) could increase the motor pathway excitability of the vibrated hand muscle and inhibit the excitability motor pathways of neighboring muscles in healthy individuals. The purpose of this study is to examine whether the vibration-induced neurophysiological changes reflect in the voluntary control of finger movements. We tested the hypothesis that MV to individual hand muscle (abductor pollicis brevis, APB; first dorsal interosseus, FDI; or abductor digiti minimi, ADM) affects the control of finger abduction/adduction. Each fingertip position was captured using a motion capture system during four experiment conditions: no MV, MV to APB, MV to FDI, and MV to ADM. Two consecutive 10-s trials in each condition were tested for each finger. We calculated individuation index (find) and index of selective activation (ISA) to compare finger independency with and without MV. The results indicated that muscle vibration could enhance the independency of finger movements.