This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation voluntee...This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography （EMG） of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak pressure was increased in the medial forefoot region, and the peak pressure was reduced in the heel region. The EMG of the medial and lateral gastrocnemius of the sound leg almost doubled and that of the rectus fomris, vastus lateralis, and vastus medialis of the prosthetic side increased to different extents with in- creasing heel heights from zero to 40 mm. These results show a high correlation with human physical be- havior. Changing of the heel heights for trans-tibial amputees during standing actually had similar effects to altering the prosthetic sagittal alignment. The results suggest that an alignment change is necessary to accommodate heel height changes and that prosthesis users should be cautious when choosing shoes.展开更多
文摘目的通过对比不同负荷认知双任务行走和运动双任务行走时下肢表面肌电(surface electromyography,sEMG)信号及动态稳定性的差异,探究不同类型和负荷双任务对健康人动态姿势控制的影响。方法利用无线sEMG测试仪和三维运动捕捉系统同时采集28名受试者不同负荷认知双任务行走和运动双任务行走时平均肌电(average electromyography,AEMG)和动态稳定性指标。采用双因素重复测量方差分析任务类型(认知任务和运动任务)和任务负荷(简单任务和困难任务)对人体下肢sEMG和动态稳定性的影响以及两者之间的交互作用。结果简单负荷行走时,左右股二头肌和右胫前肌AEMG均小于困难负荷行走(P<0.05),左胫前肌简单运动双任务行走时AEMG小于困难运动双任务行走(P<0.05)。右腓肠肌困难认知双任务行走时AEMG小于困难运动双任务行走(P<0.05),简单认知双任务行走时AEMG大于困难认知双任务行走(P<0.05),简单运动双任务行走时AEMG小于困难运动双任务行走(P<0.05);简单认知双任务行走动态稳定裕度(margins of stability,MoS)大于简单运动双任务行走(P<0.05),困难认知双任务行走MoS小于困难运动双任务行走(P<0.05),简单运动双任务行走MoS小于困难运动双任务行走(P<0.05)。结论不同类型和负荷双任务对动态姿势控制的影响存在交互效应。困难运动双任务行走时踝关节周围肌肉的神经肌肉控制和动态稳定性强于困难认知双任务行走,困难运动双任务行走时踝关节周围肌肉的神经肌肉控制和动态稳定性强于简单运动双任务行走。
基金Supported by the National Natural Science Foundation of China(No. 50575122)
文摘This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography （EMG） of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak pressure was increased in the medial forefoot region, and the peak pressure was reduced in the heel region. The EMG of the medial and lateral gastrocnemius of the sound leg almost doubled and that of the rectus fomris, vastus lateralis, and vastus medialis of the prosthetic side increased to different extents with in- creasing heel heights from zero to 40 mm. These results show a high correlation with human physical be- havior. Changing of the heel heights for trans-tibial amputees during standing actually had similar effects to altering the prosthetic sagittal alignment. The results suggest that an alignment change is necessary to accommodate heel height changes and that prosthesis users should be cautious when choosing shoes.
