Research Department, Rennes Institute of Osteopathy, Bruz, France.
Prime Institute and Sport Sciences Department, University of Poitiers, Poitiers, France.
Sports Biomech. 2020 Apr;19(2):245-257. doi: 10.1080/14763141.2018.1466906. Epub 2018 Jun 19.
Knee functional disorders are one of the most common lower extremity non-traumatic injuries reported by cyclists. Incorrect bicycle configuration may predispose cyclist to injury but the evidence of an effect of saddle setback on knee pain remains inconclusive. The aim of this study was to determine the effect of saddle setback on knee joint forces during pedalling using a musculoskeletal modelling approach. Ten cyclists were assessed under three saddle setback conditions (range of changes in saddle position ~6 cm) while pedalling at a steady power output of 200 W and cadence of 90 rpm. A cycling musculoskeletal model was developed and knee joint forces were estimated using an inverse dynamics method associated with a static optimisation procedure. Our results indicate that moving the saddle forwards was not associated with an increase of patellofemoral joint forces. On the contrary, the tibiofemoral mean and peak compression force were 14 and 15% higher in the than in the condition, respectively. The peak compression force was related to neither pedal force nor quadriceps muscle force but coincided with the eccentric contraction of knee flexor muscles. These findings should benefit bike fitting practitioners and coaches in the design of specific training/rehabilitation protocols.
膝关节功能障碍是自行车运动员最常见的下肢非创伤性损伤之一。自行车配置不当可能使自行车运动员容易受伤，但鞍座后移对膝关节疼痛影响的证据仍不明确。本研究旨在通过肌肉骨骼建模方法确定鞍座后移对蹬踏时膝关节力的影响。10 名自行车运动员在三种鞍座后移条件下（鞍座位置变化范围约 6 厘米）进行评估，同时以 200 W 的稳定功率输出和 90 rpm 的踏频蹬踏。建立了一个自行车肌肉骨骼模型，并使用与静态优化过程相关的逆动力学方法来估计膝关节力。我们的结果表明，将鞍座向前移动不会导致髌股关节力增加。相反，与 条件相比， 条件下的胫股关节平均和峰值压缩力分别高出 14%和 15%。峰值压缩力与踏板力或股四头肌力无关，但与膝关节屈肌的离心收缩同时发生。这些发现应该使自行车调整师和教练在制定特定的训练/康复方案时受益。
