不同頻率跳繩運動之下肢動作差異探討

The study of coordination among lower limb joints for different jumping frequencies of rope jumping

跳躍是人類最基本的一項動作型態，許多的運動項目也將跳繩運動當成是體能訓練之一。目的：本研究目的在探討不同跳繩運動頻率（60次／分鐘、100次／分鐘、140次／分鐘）跳繩運動之跳躍高度及下肢關節之間在下蹲期及蹬伸期時的差異性，來瞭解人體在不同頻率下跳繩運動的下肢動作控制。方法：本研究利用VICON動作捕捉系統（100Hz）擷取國小受過跳繩運動訓練的男選手15位之下肢運動學資料。結果：本研究之結果如下：一、不同頻率跳繩運動之跳躍高度、下蹲期時間百分比及蹬伸期時間百分比達顯著性差異（p＜.05），經事後比較發現跳躍高度值從高至低為60次／分鐘、100次／分鐘、140次／分鐘。下蹲期時間百分比從長至短為60次／分鐘、100次／分鐘、140次／分鐘。蹬伸期時間百分比從長至短為140次／分鐘、100次／分鐘、60次／分鐘。二、下蹲期及蹬伸期之髖、膝與踝關節角位移量，在各跳躍頻率間有達顯著差異，事後比較發現髖與踝關節之關節角位移量由大到小為60次／分鐘組、100次／分鐘組及140次／分鐘組，而膝關節之關節角位移量在100次／分鐘的角度變化比其他兩者要大。三、低頻率跳繩運動著地時的髖關節及膝關節的曲屈角度變化達顯著相關，在中、高頻率的跳繩運動起跳時的膝及踝關節的伸展角度變化達顯著相關。結論：低及中頻跳繩運動著地時期較長，下肢各關節變化較大，高頻跳繩運動著地時期縮短，下肢各關節變化減少，因此推論下肢關節在低、中頻跳繩運動受力時，緩衝效果可能較好。Rope-jump exercise is a popular activity in the elementary school. Relationship, however, between jump frequency and lower-limb motion has not been well investigated. Since knowledge of this relationship may help teacher and coach preventing from inappropriate injury in the lower limb joint. Therefore, purpose of the study was to analyze the difference and coordination among lower limb joints for different frequencies (60, 100, 140 turns/min) of rope jumping. Methods: Fifteen elementary school students served as the subjects for this study. Each participant had been trained for at least one year in rope jumping. Kinematic data were simultaneously acquired by using VICON motion system with sampling frequency 100Hz. Kinematic analysis of lower limb coordination in school child performing varied frequencies of rope-jumping exercise. Repeated measurement with one-way ANOVA was used to exam group difference. Tukey multiple comparison was used to distinguish inter-group difference (α =.05). Results: 1.The jumping height, percentage of squatting and extending phase achieve the difference significantly (p < .05). The order of jumping height from higher to lower were 60 turns/min, 100 turns/min and 140 turns/min. The order of percentage of squatting phase from longer to shorter were 60 turns/min, 100 turns/min and 140 turns/min. The order of percentage of extending phase from longer to shorter were 140 turns/min, 100 turns/min and 60 turns/min. 2. The angular change among lower limb joints including hip, knee and ankle joints during squatting and extending phase for different frequencies of rope jumping achieve the difference significantly (p < .05). The order of angular change of hip and ankle joints from larger to smaller were 60 turns/min, 100 turns/min and 140 turns/min. The angular change of knee joint was larger than those of hip and ankle joints. 3. The hip joint and knee joint of 60 turns/min during squatting phase were related significantly (p < .05). The knee joint and ankle joint of 100 turns/min and 140 turns/min during extending phase were related significantly (p < .05). Present study results indicated that jump frequency at 60 and 100 Hz produced larger joint angle in the lower limb. This suggested that lower jumping frequency may be appropriate because it may decrease the joint impact.