Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China.
Division of Kinesiology and Health, University of Wyoming, Laramie, Wyoming, USA.
Scand J Med Sci Sports. 2024 Apr;34(4):e14630. doi: 10.1111/sms.14630.
The effects of a 12-week gait retraining program on the adaptation of the medial gastrocnemius (MG) and muscle-tendon unit (MTU) were investigated. 26 runners with a rearfoot strike pattern (RFS) were randomly assigned to one of two groups: gait retraining (GR) or control group (CON). MG ultrasound images, marker positions, and ground reaction forces (GRF) were collected twice during 9 km/h of treadmill running before and after the intervention. Ankle kinetics and the MG and MTU behavior and dynamics were quantified. Runners in the GR performed gradual 12-week gait retraining transitioning to a forefoot strike pattern. After 12-week, (1) ten participants in each group completed the training; eight participants in GR transitioned to non-RFS with reduced foot strike angles; (2) MG fascicle contraction length and velocity significantly decreased after the intervention for both groups, whereas MG forces increased after intervention for both groups; (3) significant increases in MTU stretching length for GR and peak MTU recoiling velocity for both groups were observed after the intervention, respectively; (4) no significant difference was found for all parameters of the series elastic element. Gait retraining might potentially influence the MG to operate at lower fascicle contraction lengths and velocities and produce greater peak forces. The gait retraining had no effect on SEE behavior and dynamics but did impact MTU, suggesting that the training was insufficient to induce mechanical loading changes on SEE behavior and dynamics.
本研究旨在探讨为期 12 周的步态再训练方案对内侧腓肠肌（MG）和肌肉-肌腱单位（MTU）适应的影响。26 名后跟触地（RFS）的跑步者被随机分配到步态再训练（GR）组或对照组（CON）。在干预前后，在 9km/h 的跑步机跑步过程中，两次采集 MG 超声图像、标记位置和地面反作用力（GRF）。踝关节动力学以及 MG 和 MTU 的行为和动力学被定量分析。GR 组的跑步者逐渐进行了 12 周的步态再训练，过渡到前足触地模式。12 周后：（1）每组各有 10 名参与者完成了训练；8 名 GR 组参与者过渡到非 RFS，脚触地角度减小；（2）两组的 MG 肌纤维收缩长度和速度在干预后均显著降低，而两组的 MG 力在干预后均增加；（3）GR 组的 MTU 拉伸长度显著增加，两组的 MTU 最大回弹速度均显著增加；（4）各串联弹性元件参数均无显著差异。步态再训练可能会影响 MG 以较低的肌纤维收缩长度和速度运作，并产生更大的峰值力。步态再训练对 SEE 行为和动力学没有影响，但确实对 MTU 有影响，这表明训练不足以引起 SEE 行为和动力学的机械加载变化。
