健康老年人與近似正常老年中風患者在跨越不同高度障礙物時運動學及力動學上之比較

Abstract

跨越障礙物在日常生活中為一項較平地走路困難且複雜的動作，同時在復健治療上亦為用以訓練神經病患的動作之一。利用動作分析方式，比較健康者與近似正常中風病患在跨越障礙物時運動學及力動學上的不同，以了解中樞系統在輕微受損後，其對動作控制的影響。因此本研究的目的在研究輕微中風對於跨越前腳及跨越後腳在跨越障礙物時在生物力學上的影響。本實驗中，有20名近似正常中風病患及15名的健康受試者，分別跨越腳長之10%，20%以及30%高度的障礙物。結果顯示，不論是在前腳或後腳在跨越障礙物時，中風組病患藉由改變部份骨盆的活動及下肢關節角度以增加跨越腳與障礙物間的距離。同時，其站立腳所須的最大臗關節伸直肌以及膝關節屈曲肌肌力比健康老年組大。在前腳或後腳跨越障礙物時，均藉由增加臗關節伸直肌以及膝關節屈曲肌力矩使得重心減速，防止重心過快向前而跌倒。因此本研究發現中風病患在跨越障礙物時，使用較保守且安全的策略來跨越。然而，若是中風組病患其所需相關肌力不足，則向前跌倒的機會反而會增加。本研究顯示，在輕微中風後，基於安全的考量，不論患側腳為跨越前腳或跨越後腳，其產生有別於健康者之代償策略，同時也支持對近似正常中風病患於跌倒防治上，臗關節伸直肌以及膝關節屈曲肌肌力訓練是很重要且必要的。

Obstacle-crossing is one of many complex tasks associated with ambulation in the daily environment and is also one kind of rehabilitation training program for neurological patients. Kinematic and kinetic analysis of obstacle crossing between the healthy subjects and nearly-normal patients with stroke may help to understand the influence of mild central lesion on the motor control of obstacle-crossing. Therefore, the purpose of the study was to investigate the influence of mild stroke on the biomechanics of leading and trailing obstacle crossing. In the present study, 20 nearly-normal strokes and 15 health subjects were required to step over obstacles with heights of 10%, 20% and 30% leg length. The results suggested that either in the crossing of leading and trailing limb, the stroke group increased toe clearance by changing pelvic motion and associated lower limb kinematics. Moreover, the stroke group used bigger hip extensor and knee flexor moments to maintain stability during stance phase. When the swing toe was above the obstacle, the stroke group used the back muscles to decelerate the COM to prevent the COM moving forward too quickly compared to the healthy group. On the other hand, similar compensative strategies were adopted during affected-limb crossing as did during sound-limb crossing. The results suggests that different compensation strategies were used for the leading and trailing limbs following mild stroke due to the safety consideration during obstacle crossing. Moreover, knee flexor and hip extensor muscle strengthening ought to be essential and necessary for the stroke group to decrease the risks of forward tripping.