全身震動訓練對膝關節肌群之肌力與發力率的影響

Effect of Whole Body Vibration Training on Knee Extensor Muscle Strength and Rate of Force Development

前言：本研究主要是透過八星期全身震動訓練課程的介入，來探討膝關節伸展肌群與屈曲肌群的最大肌力、衝量與發力率的進步情形。方法：受試者方面，招募了二十名男性體育系學生（共二十名，平均年齡20.2±1.7歲），隨機分配成兩組，每組各十名受試者，一組為全身震動訓練組(WBV)，另一組為虛擬組(SHAM)，兩組間的訓練姿勢與課程皆相同，唯一差別為震動訓練平台震動的有無。資料收取上，透過BIODEX系統收取膝部肌群在伸展與屈曲時，最大自主收縮關節力矩(maximum joint moment)、發力率(RFD)與收縮衝量(contractile impulse)，統計方法以獨立樣本t-test比較訓練前、後兩組的進步情形。結果：根據結果發現，經過八個禮拜的訓練課程，全身震動訓練組在膝關節伸展肌群的最大關節力矩、發力率與收縮時的衝量中，皆顯著大於虛擬組，不過屈曲肌群各項參數中兩組間則均無差異存在。結論與建議：推估經過八個星期的全身震動訓練後，能提升膝部伸展肌群的肌力與爆發力，對於追求力量與速度綜合能力為基本的運動員而言，是值得參考的訓練課程，建議未來研究可從不同類型受試者、不同頻率與震動訓練時間做更廣泛之研究。

Purpose: This study compared the effects of 8-week whole-body vibration (WBV) training programs on knee extensor muscle strength and rate of force development. Methods: Twenty physically active male subjects (age: 20.2 ± 1.7 years) were randomly assigned to a whole-body vibration training group (WBV; n = 10) or a sham training group (SHAM; n = 10). SHAM group followed exactly the same training protocol as for WBV group but the platform did not vibrate. Maximal voluntary isometric joint moment， rate of force development (RFD) and contractile impulse of the knee extensors were assessed before and after the training period. Statistical analysis: Maximum moment， RFD and impulse were compared by the improvement percentage. An independent-samples T test was used to compare the improvement of knee muscle strength between WBV and sham groups. Significant level was set at 0.05. Results: There were significant differences between WBV and sham groups on improvement percentage of maximum joint moment， RFD and contractile impulse in knee extensor. Conclusions: We concluded that not only knee extensor muscle strength could be enhanced but also muscle contractile ability could be faster after a 8-week WBV training program.