坡度與老化於斜坡行走生物力學之影響

Abstract

斜坡行走為日常生活行動不可或缺的一部分，然而行走於斜坡上對於下肢造成更多挑戰。完整的斜坡行走生物力學分析有助於設計步態訓練或者預防跌倒之方法。本研究已建立年輕人於行走不同坡度斜坡時之完整下肢動力學資料，並且探討其下肢關節間以及兩腳間之協調策略，並進一步探討老年人於行走不同斜坡時之下肢生物力學。結果顯示年輕人利用增加骨盆前傾與軀幹屈曲之策略進行上坡走路，反之於下坡時利用骨盆後傾之方式行走。這些策略改變了下肢不同關節之分配與負擔。此外本研究並發現行走於平地、上坡與下坡各有明顯不同的下肢分配協調策略，下肢任一環節出問題皆會影響上下坡行走之表現。而本研究更進一步發現老年人利用骨盆更前傾但減少軀幹屈曲之策略進行上下斜坡，此策略可使老年人以保守的方式上下坡，如減少步距以及保持身體質心維持在軀幹中軸附近。此外，老年人面對斜坡之趨勢與年輕人不同，老年人以增加髖關節比重的方式面對增加坡度時所造成的負擔。而於研究老年人於行走斜坡之動態平衡的結果顯示，老年人能維持與年輕人相同前後重心傾角，但其行走速度較慢，因此若老年人於斜坡增加行走速度時，將會使前後重心傾角變大而增加跌倒之風險。

Slope walking is an inevitable part of daily living, placing more challenges on the locomotor system than level walking does. Investigating kinematics, kinetics, intra- and inter-limb load sharing patterns of the locomotor system as well as the whole body dynamic balance control during slope walking may help in devising strategies for gait retraining and fall prevention in the elderly. The work was carried out by a series of studies on the 3D kinetics, intra- and inter-limb load sharing of the lower limbs, and dynamic balance during slope in the young and elder subjects. The results showed that the young subjects increased the anterior tilt of the pelvis and the trunk flexion during uphill walking but increased the posterior tilt of the pelvis during downhill walking. The modulated moments resulted in varied mechanical demands at the lower limb joints. Distinct intra- and inter-limb load-sharing strategies were found in level, uphill and downhill walking. However, greater anterior tilt of the pelvis but lesser trunk flexion were found in the elderly during slope walking. The kinematic configuration showed that the elderly adopted a conservative strategy to decrease the step length and thus maintain the body’s COM control in the sagittal plane. The elderly were found to perform different trend with increasing slope angles compared with the young, and showed a hip strategy to meet the increased demand during slope walking. Furthermore, the elderly were found to walk with greater excursions of boby’s center of mass if they walked at the same speed as the young adults did. It indicated that the elderly suffered greater risk of sagittal instability during slope walking.