老年人肌力衰退之機轉與再強化之要訣

Mechanisms Underlying Age-related Change of Skeletal Muscle in Elderly Adults and Reconditioning Strategies

詹美華(Mei-Hwa Jan)

《物理治療》 30卷6期 (2005/12) Pp. 285-292

摘要

老年人的肌力會隨著年齡的增長而逐漸衰退，主要的因素包括肌肉組織的退化、體適能(Physical fitness)的衰退、柔軟組織彈性變差與關節活動度受限、運動神經元及其傳導速度與本體感覺器的退化及日常活動量的減少。如何根據這些退化的機轉與老年人的生理特性設計一套適合老年人的運動計畫是促進整體社會健康的重要課題。老年人的肌力訓練必須注重訓練“阻力”與“次數”的配合，盡量以中至高阻力而又不會造成退化性關節疼痛或周邊血管阻力(peripheral vascular resistance)上升的劑量為主，如此達到增加肌力與耐力的效果。運動種類的選擇上，閉鎖鍊(closed kinetic chain)運動較能刺激關節內的本體感覺器(proprioceptor)，但相對的較容易造成較大的關節內壓，引起患者的不適；「單位時間功率」的訓練與「針對功能性動作訓練特定肌肉群的運動」要比純肌力訓練在功能性動作上的改善較具優勢。另外，漸進式的阻力增加與適度的休息對老年人之運動計畫設計也是非常重要的。目前許多實驗已證實，老人的肌力經過適度的訓練，仍有很明顯的進步，常見的中老年人肌力訓練方式包括漸進快速阻力運動、結合感覺與肌肉系統的訓練、以功能性動作為導向的訓練、居家運動與社區團體操、游泳、太極拳等，皆有相當的成效。最重要的是把運動養成是日常生活習慣之一，並將這習慣持之以恆，終生保持，人生的晚年仍可健步如飛。

關鍵字

老年人 ； 肌力 ； 肌耐力 ； 阻力運動

並列摘要

Muscle strength of the elder population decreases with increasing age. Atrophy of muscle tissue, decline of physical fitness, decreased flexibility of soft tissue, limited range of motion of joints, deficits of motor neurons and proprioception, and lessening of daily activities are all factors that contribute to decreased muscle strength. How to develop an appropriate strength-training program for the elderly according to their physical status is a vital issue in health promotion of the society. Appropriate dose (load ×repetition) of a strength training program needs to provide adequate intensity to prompt the improvement of muscle strength and endurance, without resulting in discomfort of joints or causing an increase of peripheral vascular resistance. As to exercise type, closed chained exercise can successfully stimulate the proprioceptors within joints, but on the other hand, would increase the intra-pressure of joints, and thus inducing pain; power training and task-orientated training results in better improvements of the patients' activity of daily living (ADL). Furthermore, advancement of load gradually, according to the patient's improvement, and rest between sets should also be carefully considered. Various studies have proved that through appropriate training, muscle strength of the aged could be significantly improved. Commonly recommended exercises include progressive high velocity resistance training, training which organizes the sensory and muscle systems, task-orientated training, home or community-based training programs, swimming and Taichi. Most important of all, to keep exercising as a good habit and never giving it up will guarantee you a good health condition even at the age of eighty or more!

並列關鍵字

Elderly ； Muscle strength ； Endurance ； Strength-training