不同頻率全身震動對下肢運動表現之立即性影響

Abstract

目的： 本研究目的是探討兩種不同頻率(肌梭激發頻率與下肢肌肉共震頻率)全身性震動對於下肢運動表現之立即性影響。方法：本研究以15位一般人為受試者，並依照平衡次序法分別做三組刺激(高頻組：頻率32 Hz、震幅1 mm。低頻組：頻率18 Hz、震幅3 mm。控制組：無震動刺激)，分別在震動平台上做60 秒，2 秒1 次的蹲踞訓練，每次訓練五組。刺激前後以測力板擷取連續三次垂直跳與單足閉眼站立平衡，同時以Biopac MP 150 擷取股直肌與股二頭肌肌肉活性做事後探討。結果：研究結果發現，連續三次垂直跳第一跳中，高頻組與低頻組跳躍高度前後測達顯著進步(p<.05)，且高頻組進步率最高(5.37%)，而肌肉電位三組差異率皆呈現下降的趨勢。連續三次垂直跳第二跳中，低頻組在起跳高度進步幅度最高(17.1%)，而股直肌活性差異值最低(-15.4%)。在單足閉眼站立平衡項目中高頻組與低頻組在重心位移速度上進步率皆提升(3.8%與1.9%)，控制組則為下降(-2.89%)，肌肉電位三組皆呈現下降的趨勢。結論：研究結論為震動組對於連續三次垂直跳之第一跳高度有顯著增進，且高頻組較優異，同時對平衡能力也有增加，控制組則無。

The aim of this study was to explore the immediate effect of whole body vibration with two different frequencies (muscle spindle stimulus frequency and lower-limb muscle resonance frequency) on the sport performance of lower limbs.Fifteen subjects were recruited to participate in this study. Subjects were asked to stand on the vibration plate and three types of stimulus frequency were given to the subjects in the order of (1)high frequency vibration (HFV) group: frequency = 18Hz,amplitude = 3mm; (2)low frequency group (LFV): frequency = 32Hz, amplitude = 1mm; (3)control group (CON): no vibration stimulus. While receiving stimulus frequencies, subjects were also doing squat-stand movement in a 60-second cycle (2 seconds per squat-stand) and each subject performed 5 cycles for each group. AMTI force plate was applied pre and post tests to measure three consecutive counter movement jumps (CMJ3) as well as balance tests (BT) of one leg stance with eyes closed. In addition, Biopac MP 150 was used simultaneously to collect EMG activity of rectus femoris and biceps femoris.The results show that for the first jump of CMJ3, except the CON group, both HFV group and LFV group improved significantly in jump height (p<.05) pre and post tests, especially HFV group improved as much as 5.37%. On the other hand, all three groups show a decreasing tendency in EMG activity. For the second jump of CMJ3, LFV group improved the most (17.1%), but also show the greatest decrease in the EMG activity As for BT results--the speed of displacement of body’s center of gravity, HFV group and LFV group increased 3.8% and 1.9% respectively while the CON group decreased by -2.89%. All three groups present a tendency to decreasein EMG activity. We conclude that the HFV group and LFV group improved significantly in the first jump of CMJ3 (HFV group improved the most) and their balance abilities have also increased while no improvement showed in both tests for the CON group.