Seratiuk Flores Heloisa, Wen Liang Yeoh, Loh Ping Yeah, Morinaga Kosuke, Muraki Satoshi
Graduate School of Design, Human Life Design and Science, Kyushu University, Fukuoka, Japan.
Faculty of Science and Engineering, Saga University, Saga, Japan.
PLoS One. 2025 Jan 7;20(1):e0317121. doi: 10.1371/journal.pone.0317121. eCollection 2025.
Cycling is a beneficial physical activity for rehabilitating individuals with lower-limb amputations and serves as a feasible leisure sport. However, the optimal bicycle configuration for cycling with a unilateral transtibial prosthesis at leisure levels has not been investigated. For saddle height at professional cycling levels, existing literature suggests utilizing the same configuration as that used by intact cyclists, where the knee reaches 25-35° at maximum extension. However, leisure cyclists tend to select lower saddle heights, and cycling with a unilateral transtibial prosthesis infers altered biomechanics during cycling practice. This study aimed to investigate the effects of cycling at different saddle heights with a simulated unilateral prosthesis. Ten able-bodied participants wore orthoses to simulate prosthetic conditions. The experimental task was performed on an ergometer at 40 W resistance, 60 rpm to simulate leisure cycling. Standard saddle height was defined as maximum knee extension of 45°. This height was used as the control condition and its trials were performed without orthoses. The variable heights were set as height percentage variations (-7%, -3.5%, 0, +3.5%, and +7%). Muscle activity, joint movement, force application to the pedals, perceived exertion, and comfort were evaluated. The -3.5% and -7% saddle heights resulted in joint movement and muscle activity levels closer to those in the control conditions, which also showed improved power symmetry between the affected and non-affected legs. In addition, the -3.5% height increased comfort level in participants. In conclusion, selecting lower saddle heights may be beneficial for unilateral transtibial amputees during leisure cycling. The optimal saddle height for this population may maintain maximum knee extension within the 37-45° range, dynamically measured on the affected side.
骑自行车对于下肢截肢者的康复是一项有益的体育活动，也是一项可行的休闲运动。然而，针对单侧经胫骨截肢者在休闲骑行时的最佳自行车配置尚未进行研究。对于职业骑行水平的鞍座高度，现有文献建议采用与健全骑行者相同的配置，即膝关节在最大伸展时达到25-35°。然而，休闲骑行者往往会选择较低的鞍座高度，并且使用单侧经胫骨假肢骑行会在骑行过程中导致生物力学改变。本研究旨在调查使用模拟单侧假肢在不同鞍座高度骑行的影响。十名身体健全的参与者佩戴矫形器以模拟假肢情况。实验任务在测力计上以40W阻力、60转/分钟进行，以模拟休闲骑行。标准鞍座高度定义为膝关节最大伸展45°。该高度用作对照条件，其试验在不佩戴矫形器的情况下进行。可变高度设置为高度百分比变化（-7%、-3.5%、0、+3.5%和+7%）。评估肌肉活动、关节运动、踏板受力、主观用力感觉和舒适度。鞍座高度为-3.5%和-7%时，关节运动和肌肉活动水平更接近对照条件，同时患侧和非患侧腿之间的功率对称性也有所改善。此外，-3.5%的高度提高了参与者的舒适度。总之，选择较低的鞍座高度可能对单侧经胫骨截肢者休闲骑行有益。该人群的最佳鞍座高度可能是在患侧动态测量时将膝关节最大伸展保持在37-45°范围内。
