Differences in muscle activation patterns during step recovery in elderly women with and without a history of falls
Differences in muscle activation patterns during step recovery in elderly women with and without a history of falls
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DOI：
10.1007/s40520-013-0152-4
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发表时间：
2014-04-01
影响因子：
4
通讯作者：
Ichihashi, Noriaki
中科院分区：
文献类型：
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作者：
Ochi, Akira;Yokoyama, Shinya;Ichihashi, Noriaki
背景和目的本研究旨在比较有和没有跌倒病史的受试者在向前跌倒中恢复平衡时所使用的肌肉激活模式，并确定恢复步态功能障碍的原因。方法有跌倒史和无跌倒史的老年妇女(跌倒者12例，平均年龄+/-SD=82.8+/-4.5岁；未跌倒者17例，年龄=81.4+/-3.4岁)参与研究。受试者被一根倾斜控制绳索悬挂在前倾位置，负荷为体重的15%，并指示受试者在释放时通过向前迈出一步来恢复站立平衡。对步态侧的5块小腿肌肉进行肌电检测，比较跌倒组和非跌倒组的肌电活动模式。在足部抬起前提供推力的腓肠肌的肌电峰值时间，跌倒者比非跌倒者慢，而股二头肌和腓肠肌的肌电起始时间在两组之间相似。与非跌倒组相比，跌倒组的大腿肌肉失活明显延迟，股直肌和股二头肌之间的协同收缩增加。结论有跌倒病史的老年女性在恢复平衡过程中的肌肉激活模式可能反映了她们不能快速向前迈进。
Background and aims This study aimed at comparing the patterns of muscle activation used in stepping to regain balance during a forward fall between subjects with and without a history of falling and at identifying the causes of functional deficits in recovery stepping.Methods Elderly women with and without a history of falling (fallers: n = 12, mean age +/- SD = 82.8 +/- 4.5 years; non-fallers: n = 17, age = 81.4 +/- 3.4 years) participated in the study. The subjects were suspended in a forward-leaning position by a lean-control cable with a load of 15 % of body weight and instructed to regain standing balance upon release by taking a single step forward. Electromyography (EMG) data were obtained from five lower extremity muscles on the stepping side, and the muscle activation patterns were compared between fallers and non-fallers.Results Fallers had a shorter step length and slower step velocity than non-fallers. The EMG time-to-peak for the gastrocnemius muscle, which provides push-off prior to foot lift-off, was slower for fallers than for non-fallers, whereas the EMG onset times of the biceps femoris and gastrocnemius muscles were similar between the groups. The fallers exhibited significantly delayed muscle deactivation of the upper leg and increased co-contraction between the rectus femoris and biceps femoris during the stepping phase than did the non-fallers.Conclusions These findings suggest that the muscle activation pattern during the regain balance may reflect an inability to step forward rapidly in elderly women with a history of falls.