Kovács Bálint, Hegyi András, Yaodong Gu, Kóbor István, Gyebnár Gyula, Tihanyi József, Péter Annamária
Faculty of Sport Science, Ningbo University, Ningbo, PR China; Department of Kinesiology, Hungarian University of Sports Science, Budapest, Hungary.
Department of Kinesiology, Hungarian University of Sports Science, Budapest, Hungary.
J Biomech. 2025 Mar;182:112557. doi: 10.1016/j.jbiomech.2025.112557. Epub 2025 Feb 1.
The length of the Achilles tendon moment arm may affect muscle shortening velocity, ankle moment, and running economy in running. Regarding the direction of these effects, experimental studies are controversial. These typically use simplified 2-D methods to define the length of the moment arm, and data on high-level athletes are scarce. The purpose of this study was to use a 3-D approach to estimate the length of the Achilles tendon moment arm and examine its association with sprint and endurance running performance in high-level competitive runners. Twenty-nine healthy adult competitive runners were recruited, including fifteen distance runners (IAAF score = 953 ± 116, mean ± standard deviation) and fourteen sprint runners (IAAF score = 993 ± 113). The length of the Achilles tendon moment arm was estimated from T1 weighted MRI scans taken at a 90° ankle angle. The sprint runners had longer Achilles tendon moment arms compared to the distance runners when considering absolute lengths (51.8 ± 2.1 mm vs. 48.7 ± 3.8 mm, p = 0.017, Cohen's d = -0.94), as well as after normalizing to body height (p = 0.004, d = -1.14). However, we did not find any correlation between the absolute or normalized Achilles tendon moment arm length and personal best running performance in either group. However, longer moment arm may be due to the relatively larger plantar flexor muscle size which can probably offset the detrimental effects of a longer moment arm. On the other hand, distance runners may benefit from a relatively shorter moment arm due to lower forces and increased need for fatigue-resistance. We found no evidence that plantar flexor moment arm is detrimental to running performance in either group, therefore, practitioners should not be concerned about the effects of increasing muscle size on the increase in Achilles tendon moment arm.
跟腱力臂的长度可能会影响跑步时肌肉的缩短速度、踝关节力矩和跑步经济性。关于这些影响的方向，实验研究存在争议。这些研究通常使用简化的二维方法来定义力臂的长度，而关于高水平运动员的数据很少。本研究的目的是使用三维方法来估计跟腱力臂的长度，并研究其与高水平竞技跑步者短距离冲刺和耐力跑表现之间的关联。招募了29名健康的成年竞技跑步者，包括15名长跑运动员（国际田联评分=953±116，平均值±标准差）和14名短跑运动员（国际田联评分=993±113）。跟腱力臂的长度是根据在踝关节90°角度拍摄的T1加权MRI扫描图像估算得出的。考虑绝对长度时，短跑运动员的跟腱力臂比长跑运动员更长（51.8±2.1毫米对48.7±3.8毫米，p=0.017，科恩d值=-0.94），在根据身高进行归一化处理后也是如此（p=0.004，d值=-1.14）。然而，我们没有发现任何一组中跟腱力臂的绝对长度或归一化长度与个人最佳跑步成绩之间存在相关性。不过，力臂较长可能是由于跖屈肌相对较大，这可能抵消了力臂较长带来的不利影响。另一方面，长跑运动员可能因受力较小且对耐疲劳性的需求增加而受益于相对较短的力臂。我们没有发现证据表明跖屈肌力臂对任何一组的跑步表现有害，因此，从业者不应担心肌肉大小增加对跟腱力臂增加的影响。
