Research of effects of 18-months exercise training program on balancing ability against abrupt deceleration in the elderly

本研究旨在探讨为期18个月的多维运动训练对老年人抗突然减速平衡能力的影响。20名居住在社区的健康老年人(≧，65岁)在过去6个月内没有一次或更少跌倒的病史。将受试者分为运动组和对照组各10例。为期18个月的运动训练计划旨在增加力量、下肢灵活性、动态平衡和日常生活能力。对照组未接受任何干预。测量平台减速后体位摆动时足底中心压力(CFP)的变化，并评估反应时间和CFP位移。测量突然加速时胫前肌和腓肠肌内侧肌的肌电起始点，并计算下肢肌组拮抗肌共收缩的相对水平。此外，还测量了运动和感觉能力。训练组训练后反应时和突然减速后即刻CFP移位较训练前有明显改善。训练组训练后CCI明显低于训练前。训练组在屈、背屈肌力、伸膝肌力量、踝关节和髋关节屈曲能力、选择反应时间、单腿平衡时间、坐立时间、尽可能快的步行速度等方面均有明显改善。这些结果表明，这种为期18个月的运动训练可以提高对抗突然减速的平衡能力，从而降低跌倒的风险-这可能是因为神经肌肉功能的改善。

The purpose of this study was to examine the effects of 18-months multidimensional exercise training on balancing ability against abrupt deceleration in the elderly. Twenty community-dwelling healthy elderly (≧65 years of age) with no history of one or less falls in the previous 6 month participated. They were classified into exercise group (n=10) and control group (n=10). The 18-month exercise training program was designed to increase strength, flexibility of the lower extremities, dynamic balance and ADL. The control group received no intervention. Changes in the center of foot pressure (CFP) were measured during postural sway following platform deceleration, and the response time and CFP displacement were evaluated. The EMG onset in the tibialis anterior muscle and medial gastrocnemius muscle during abrupt acceleration was measured, and the relative level of co-contraction of antagonistic muscles (CCI) in the lower extremity muscle group was calculated. In addition, motor and sensory abilities were measured. Significant improvement were observed in training group for the response time and CFP displacement immediately after abrupt deceleration in post-training vs pre-training. CCI in training group was significantly lower in post-training than in pre-training. Significant improvement were observed in training group for the strength of planterfiexor and dorsiflexor muscles, and knee extensor muscle, flexibilities of ankle and hip joints, choice reaction time, one leg balancing time, time to sit-to-stand, and speed of walking as fast as possible. These results suggest that this exercise training for 18-month can improve the balancing ability against abrupt deceleration, thereby reducing risk for falls - This may be because improvement of neuro-muscular function.