肌肉長度對人體股四頭肌最大等長自主收縮及徵召的影響

The Effect of Muscle Length on Maximal Isometric Voluntary Contraction and Activation of Quadriceps in Human

蕭世芬(Shih-Fen Hsiao) ； 許弘昌(Horng-Chaung Hsu)

《醫護科技學刊》 1卷2期 (1999/10) Pp. 131-145

https://doi.org/10.6563/TJHS.1999.1(2).1

摘要

對大多數的復健專業人士而言，由於面對的許多動作有問題或失能的病患在做行動時皆有肌肉徵召不足的問題，病人是否能夠完全徵召一塊肌肉，並使其做出最大自主收縮是他們很關心的一個問題。在本研究中探討的是一群健康成人的股四頭肌，在不同膝關節角度下的等長肌力及自主徵召能力。同意參與的受試者被要求做出一連串的股四頭肌最大自主收縮，測試的角度包括膝關節屈曲10°，30°，60°及90°，測試的順序隨機。在這些角度下，自主徵召及徵召失敗的程度，是對股四頭肌施以每秒一次的超強電刺激以抽搐上加技術來檢測。所有的受試者都能接受這樣的施測程序。結果顯示，不管是自主或電刺激產生的肌力皆呈現長度－力量相關關係；也就是說，膝關節伸得愈直，所能產生的肌力愈小。這些變化在統計學上都有顯著的意義。但是，並不是所有的受試者都可以完全徵召他們的股四頭肌，也只有一個受試者可以在所有的四個測試角度都達到完全的自主徵召。在不同的膝關節角度下，自我徵召的能力並沒有顯著的差異，不過，在膝關節彎曲90°時自主徵召失敗的程度則是明顯的偏低（VA = 6.5% ± 0.28）。雖然受試人數較少，本實驗的結果仍顯示自主徵召能力可能不受肌肉長度的影響。將來需要繼續更多的實驗以下定論。未來在動態肌肉收縮方面研究的需要也在文中一併探討。

關鍵字

等長收縮 ； 自主徵召 ； 抽搐上加技術 ； 物理治療

並列摘要

The ability to fully activate a human muscle is of great interest to most rehabilitation professionals, since most of the clients with movement disorders or disability have difficulty in recruiting their muscles during movement. In this study isometric quadriceps strength and voluntary activation at different knee angles were investigated in a group of healthy adults. Consented subjects were asked to do a series of maximal isometric contractions through a movement range 30°-90° of knee flexion at 30° increment, plus 10° of knee flexion, in random order. The level of voluntary activation and activation failure at the same angle was estimated by the twitch superimposition technique, using a 1 Hz supramaximal electrical stimulation. All subjects tolerated the experimental procedure well. The results showed both the voluntary and stimulated maximal forces followed the length-tension relationship; the force declined as the knee moves into extension. The length related change in voluntary and stimulated force production was both statistically significant. However, not every subject could fully activate their quadriceps, and none but one subject could fully activate the quadriceps at all knee angles tested. There was no significant difference in the level of activation failure at different knee angles except 90°; the minimal activation failure was found at this particular angle as well (VA = 6.5 % ± 2.8). Despite the small sample number, the result suggests voluntary activation failure may not be affected by muscle length. More subjects are needed for further investigation. Possibility of research into dynamic muscle contraction is explored and discussed.

並列關鍵字

isometric contraction,voluntary activation,twitch superimposition,physical therapy