踝內翻外翻肌力與平衡控制的相關

The Relationship between ankle inversion/eversion strength and balance control ability

前言：腳踝扭傷是常見的運動傷害，而下肢肌力的不平衡是一種可能的原因，平衡是指人體重心保持在一定的身體支撐基底（base of support）範圍內的能力，也就是維持身體重心（COG）在一支撐面的能力（Nashner，1993），良好的平衡控制能力對日常生活是相當重要的，除可預防跌倒與傷害之發生，更是傑出運動表現之基石，本研究的目的在探討踝內翻外翻肌力值與Kisterler測力板所得之站立平衡表現之間的關係。方法：28位每週有適度運動的健康大學生，以隨機分派、交叉對抗分組進行Kisterler測力板單腳站立平衡測驗（開眼左腳、開眼右腳、閉眼左腳與閉眼右腳），與Biodex等速踝關節肌力測量（角速度為30°／s與120°／s下之內翻外翻最大、平均扭力與平均動力值），資料收集後以SPSS／Windows，進行描述性統計與Pearson相關係數分析各變項間之關係，以獨立樣本t考驗比較雙腳各變項之差異。結果：一、於30°／s下踝內翻外翻肌力值雙腳間無差異，而在120°／s下踝內翻外翻肌力值雙腳間外翻無差異，但雙腳間的內翻肌力值有差異（t＝2.2～3.1），且右腳內翻肌力顯著大於左腳；二、不論是開眼或是閉眼中平衡控制能力無差異，然而雙腳在閉眼情境之平衡控制能力顯著較開眼情境為差（t＝-2.7～-3.4）；三、不論在30°／s或是120°／s下，雙腳最大扭力、平均最大扭力與平均動力值間皆有顯著關係（r＝.72～.98，p＜.01），然皆與開或閉眼情境之平衡控制無顯著關係。結論：研究結果顯示踝內翻與外翻肌力似乎與個體平衡控制能力無顯著相關，然而在高速動作中（120°／s），個體左腳與右腳間踝內翻肌力值有顯著差異，此現象與踝傷害機率的關係，以及右腳內翻肌力顯著大於左腳的機制，仍需更多的研究加以探討，後續研究應嘗試採用動態平衡測量儀器，並探討平衡相關肌群與本體感覺功能與其之關係與影響，以進一步分析與瞭解平衡控制的相關因素。INTRODUCTION: Balance is the process of maintaining the center of gravity (COG), the point of maximal stability in postural stance, within the body's base of support, the area within the perimeter of contact between the surface and the two feet. The balance control system operates as a feedback control circuit between the brain and the musculoskeletal system. The musculature of the legs, feet, and trunks, using this feedback circuit, allows the individual to stand erect against the force of gravity. The purpose of this study was to evaluate the relationship between ankle inversion/eversion (E/I) strength and balance control ability. METHODS: Twenty-eight healthy physically active college students recruited as subjects. Random assigned and counter balanced design to undertake the Kisterler force plate balance test (open and close eye with left or right leg upright standing) and the Biodex ? ankle E/I strength (peak and average peak torque, PT & APT at 30°/s & 120°/s). Data analyzed using descriptive statistic, Pearson correlation and independent t test to compare the difference between them. RESULTS: 1) There were no significant differences in ankle E/I strength at 30°/s and eversion strength at 120°/s between each leg, but significantly difference were found in ankle inversion strength at 120°/s (t=2.2~3.1). 2) There were no difference were found in balance performance between two leg either open or close eye test, but the balance performance is better in open eye test than close eye test (t=-2.7~-3.4). 3) There were strong relationship between PT and APT (r=.72~.98, p<.01), but have no relationship with balance performance in open or close test. CONCLUSION: The results showed that during lower speed testing (30°/s), the ankle E/I strength seem to be unconcerned with the balance control ability. But during the higher speed testing (120°/s), the right leg inversion strength is stronger that left leg. Consideration of the ankle injuries were mostly occurred in intense and high-speed movements, more studies are needed to clarify and examined the relationship between the imbalance muscle strength in high speed and the dynamic balance control ability. Further study also could focus on the relative muscular activity or proprioception on balance control, even in the dynamic balance test, to clarify and examine the underlying mechanisms.