中高齡者下肢發力率與運動生物力學的跌倒風險因子之相關探討

Abstract

目的：本研究目的為探討中高齡者跌倒經驗與下肢發力率對平衡及步態運動生物力學的跌倒風險因子間的關聯。方法：招募25名60歲以上中高齡者進行實驗，依據過去一年跌倒經驗分組 (無跌倒經驗13人，有跌倒經驗12人)。實驗包含髖、膝、踝關節發力率測試、開與閉眼雙腳站立平衡測試及步態測驗，統計以逐步迴歸方式分析，探討中高齡者下肢發力率與跌倒經驗對平衡及步態運動生物力學跌倒風險因子之間能否產生預測力。結果：研究結果顯示，踝關節背屈50ms發力率對開、閉眼CoP額狀面位移距離均方根具中度影響力 (r2 = 0.19, p = 0.02; r2 = 0.32, p< 0.01)；跌倒經驗使膝關節伸展150ms發力率對開、閉眼CoP額狀面平均晃動速度有顯著預測力 (r2 = 0.21, p = 0.01; r2 = 0.18, p = 0.02)；步態表現方面，踝關節背屈150ms發力率對步幅距離 (r2 = 0.25, p < 0.01)，跌倒經驗使膝關節伸展50ms發力率對步幅時間 (r2 = 0.34, p < 0.01)，以及跌倒經驗使髖關節伸展150ms對雙腳支撐期比率 (r2 = 0.26, p < 0.01) 的預測力最為顯著。結論：訓練高齡者踝關節背屈50ms發力率有助於提升平衡穩定性，對於曾經有跌倒經驗的高齡者，應特別著重於膝關節伸展、髖關節屈曲與伸展發力率訓練，以降低跌倒風險。Purpose: The purpose of this study was to investigate the relationship between fall experience and lower limb rate of torque development (RTD) with balance and gait-related biomechanical risk factors for falls in middle-aged and older adults. Methods: Twenty-five participants aged 60 and above were recruited and divided into two groups based on fall history in the past year (13 withno fall experience, 12 with fall experience). The experiment included tests of RTD at the hip, knee, and ankle joints, balance tests under eyes-open and eyes-closed double-leg stance conditions, and gait assessments. Stepwise regression analysis was used to examine whether lower limb RTD and fall experience could predict balance and gait-related biomechanical fall risk factors. Result: The results showed that ankle dorsiflexion RTD at 50ms had a moderate influence on the root mean square (RMS) of CoP (center of pressure) mediolateral displacement under both eyes-open and eyes-closed conditions (r²=0.19, p=0.02; r²=0.32, p<0.01). Fall experience enabled knee extension RFD at 150ms to significantly predict the mean velocity of mediolateral CoP sway in both conditions (r²=0.21, p=0.01; r²=0.18, p=0.02). Regarding gait performance, ankle dorsiflexion RTD at 150ms was a significant predictor of step length (r²=0.25, p<0.01); fall experience enabled knee extension RTD at 50ms to significantly predict step time (r²=0.34, p<0.01), and hip extension RTD at 150ms to significantly predict double support phase ratio (r²=0.26, p<0.01). Conclusion: Training ankle dorsiflexion RTD at 50ms may help enhance balance stability in older adults. For those with a history of falls, special attention should be given to training knee extension and hip flexion/extension RTD to reduce the risk of falls.