a Laboratory of Biomechanics, Department of Sport Sciences, Aristotle University of Thessaloniki , Greece.
J Sports Sci. 2013;31(16):1789-96. doi: 10.1080/02640414.2013.803587. Epub 2013 Jul 23.
The aim of the present study was to investigate the kinematic and kinetic differences in the execution of vertical jumps between individuals with good and poor ankle dorsiflexion. Fifteen physical education students were assigned to the flexible group (FG), while another 15 were assigned to the inflexible group (IFG). The two groups executed countermovement jumps (CMJ) and drop jumps from a 60 cm height (DJ60). For the CMJ, the FG jumped higher (32.0 ± 4.0 cm vs. 30.2 ± 4.9 cm, P = 0.27) and used a greater range of motion in all leg joints. The IFG jumpers raised their heels off the ground and had a greater horizontal distance between the centre of mass of the trunk and the centre of the hip joint (LCMh 25.6 ± 3.4 cm vs. 30.9 ± 4.3 cm, P < 0.001). In the DJ60 the FG jumped higher (22.4 ± 5.9 cm vs. 19.5 ± 4.6 cm, P = 0.14) with a greater vertical shift of the body centre of mass (BCM) (S = 0.45 ± 0.11 cm vs. 0.36 ± 0.05 cm, P < 0.01) and better joint coordination. The IFG jumpers changed the position of their trunk and heels depending on the jump type. Trainers should reconsider the technical issues of vertical jumps according to the flexibility of the ankle joint.
本研究旨在探讨踝关节背屈活动度良好和不良者在执行垂直跳跃时的运动学和动力学差异。15 名体育系学生被分配到灵活组（FG），另外 15 名被分配到僵硬组（IFG）。两组均执行了反向跳跃（CMJ）和从 60cm 高处跳下（DJ60）。对于 CMJ，FG 跳得更高（32.0 ± 4.0cm 比 30.2 ± 4.9cm，P = 0.27），并且所有腿部关节的运动幅度更大。IFG 跳跃者的脚跟离开地面，并且躯干质心与髋关节中心之间的水平距离更大（LCMh 25.6 ± 3.4cm 比 30.9 ± 4.3cm，P < 0.001）。在 DJ60 中，FG 跳得更高（22.4 ± 5.9cm 比 19.5 ± 4.6cm，P = 0.14），身体质心（BCM）的垂直位移更大（S = 0.45 ± 0.11cm 比 0.36 ± 0.05cm，P < 0.01），并且关节协调性更好。IFG 跳跃者根据跳跃类型改变了他们的躯干和脚跟的位置。教练员应根据踝关节的灵活性重新考虑垂直跳跃的技术问题。
