Monte Andrea, Tecchio Paolo, Nardello Francesca, Zamparo Paola
Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, 37124 Verona, Italy.
Human Movement Science, Faculty of Sports Science, Ruhr University Bochum, 44801 Bochum, Germany.
Biology (Basel). 2022 Jun 14;11(6):912. doi: 10.3390/biology11060912.
Walking at speeds higher than transition speed is associated with a decrease in the plantar-flexor muscle fibres’ ability to produce force and, potentially, to an impaired behaviour of the muscle−tendon unit (MTU) elastic components. This study aimed to investigate the ankle joint functional indexes and the Achilles tendon mechanical behaviour (changes in AT force and power) to better elucidate the mechanical determinants of the walk-to-run transition. Kinematics, kinetic and ultrasound data of the gastrocnemius medialis (GM) were investigated during overground walking and running at speeds ranging from 5−9 km·h−1. AT and GM MTU force and power were calculated during the propulsive phase; the ankle joint function indexes (damper, strut, spring and motor) were obtained using a combination of kinetic and kinematic data. AT force was larger in running at speeds > 6.5 km/h. The contribution of AT to the total power provided by the GM MTU was significantly larger in running at speeds > 7.5 km/h. The spring and strut indexes of the ankle were significantly larger in running at speeds > 7.5 km/h. These data suggest that the walk-to-run transition could (at least partially) be explained by the need to preserve AT mechanical behaviour and the ankle spring function.
以高于转换速度的速度行走与跖屈肌纤维产生力量的能力下降有关，并且可能与肌腱单元（MTU）弹性成分的行为受损有关。本研究旨在调查踝关节功能指标和跟腱力学行为（跟腱力和功率的变化），以更好地阐明步行到跑步转换的力学决定因素。在地面行走和以5-9 km·h−1的速度跑步过程中，对腓肠肌内侧头（GM）的运动学、动力学和超声数据进行了研究。在推进阶段计算跟腱和GM MTU的力和功率；使用动力学和运动学数据的组合获得踝关节功能指标（阻尼器、支柱、弹簧和电机）。速度>6.5 km/h跑步时跟腱力更大。速度>7.5 km/h跑步时，跟腱对GM MTU提供的总功率的贡献显著更大。速度>7.5 km/h跑步时，踝关节的弹簧和支柱指标显著更大。这些数据表明，步行到跑步的转换（至少部分）可以通过保持跟腱力学行为和踝关节弹簧功能的需要来解释。
