Mizuno T, Umemura Y
Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan.
Int J Sports Med. 2016 Dec;37(13):1044-1050. doi: 10.1055/s-0042-108807. Epub 2016 Sep 27.
The purpose of this study was to identify changes in ankle range of motion and passive mechanical properties of the muscle-tendon unit after dynamic stretching. 12 healthy subjects participated in this study. Displacement of the muscle-tendon junction was measured using ultrasonography while the ankle was passively dorsiflexed at 1°/sec to its maximal dorsiflexion angle. Passive torque was also measured using an isokinetic dynamometer. Measurements were conducted pre-intervention, immediately after the intervention and 5, 10, 15 and 30 min post-intervention. The dynamic stretching consisted of four 30-s periods of ankle dorsiflexion and plantarflexion. Ankle range of motion was significantly increased immediately (from 18.3±1.8° to 21.4±1.7°) and 10 min (20.9±1.9°) after dynamic stretching, but this change disappeared within 15 min. However, stiffness of the muscle-tendon unit and displacement of the muscle-tendon junction at the submaximal dorsiflexion angle did not differ between the experimental conditions. These results demonstrate that dynamic stretching by contracting an antagonist muscle group increases ankle range of motion temporarily without changing the passive mechanical properties of the muscle-tendon unit. The increased range of motion of the ankle after dynamic stretching might be caused by enhanced stretch tolerance.
本研究的目的是确定动态拉伸后踝关节活动范围以及肌腱单元被动力学特性的变化。12名健康受试者参与了本研究。在踝关节以1°/秒的速度被动背屈至最大背屈角度时，使用超声测量肌腱连接点的位移。还使用等速测力计测量被动扭矩。在干预前、干预后立即以及干预后5、10、15和30分钟进行测量。动态拉伸包括四个30秒的踝关节背屈和跖屈阶段。动态拉伸后立即（从18.3±1.8°增加到21.4±1.7°）以及10分钟后（20.9±1.9°）踝关节活动范围显著增加，但这种变化在15分钟内消失。然而，在次最大背屈角度时，肌腱单元的刚度和肌腱连接点的位移在各实验条件之间并无差异。这些结果表明，通过收缩拮抗肌群进行动态拉伸可暂时增加踝关节活动范围，而不会改变肌腱单元的被动力学特性。动态拉伸后踝关节活动范围增加可能是由于拉伸耐受性增强所致。
