Department of Kinesiology, Recreation and Sport Studies, The University of Tennessee, Knoxville, TN 37996, USA.
Department of Kinesiology, Recreation and Sport Studies, The University of Tennessee, Knoxville, TN 37996, USA.
J Sport Health Sci. 2020 May;9(3):258-264. doi: 10.1016/j.jshs.2019.07.011. Epub 2019 Sep 5.
Q-Factor (QF), or the inter-pedal width, in cycling is similar to step-width in gait. Although increased step-width has been shown to reduce peak knee abduction moment (KAbM), no studies have examined the biomechanical effects of increased QF in cycling at different workrates in healthy participants.
A total of 16 healthy participants (8 males, 8 females, age: 22.4 ± 2.6 years, body mass index: 22.78 ± 1.43 kg/m, mean ± SD) participated. A motion capture system and customized instrumented pedals were used to collect 3-dimensional kinematic (240 Hz) and pedal reaction force (PRF) (1200 Hz) data in 12 testing conditions: 4 QF conditions-Q1 (15.0 cm), Q2 (19.2 cm), Q3 (23.4 cm), and Q4 (27.6 cm)-under 3 workrate conditions-80 watts (W), 120 W, and 160 W. A 3 × 4 (QF × workrate) repeated measures of analysis of variance were performed to analyze differences among conditions (p < 0.05).
Increased QF increased peak KAbM by 47%, 56%, and 56% from Q1 to Q4 at each respective workrate. Mediolateral PRF increased from Q1 to Q4 at each respective workrate. Frontal-plane knee angle and range of motion decreased with increased QF. No changes were observed for peak vertical PRF, knee extension moment, sagittal plane peak knee joint angles, or range of motion.
Increased QF increased peak KAbM, suggesting increased medial compartment loading of the knee. QF modulation may influence frontal-plane joint loading when using stationary cycling for exercise or rehabilitation purposes.
在自行车运动中，Q 因子（QF）或足间距类似于步态中的步宽。尽管已经表明增加步宽可以降低峰值膝关节外展力矩（KAbM），但尚无研究在健康受试者的不同工作率下检查自行车 QF 增加的生物力学影响。
共有 16 名健康参与者（8 名男性，8 名女性，年龄：22.4±2.6 岁，体重指数：22.78±1.43kg/m2，平均值±标准差）参加了研究。使用运动捕捉系统和定制的仪器化脚踏板来收集 3 维运动学（240Hz）和脚踏反应力（PRF）（1200Hz）数据，共 12 种测试条件：4 种 QF 条件-Q1（15.0cm）、Q2（19.2cm）、Q3（23.4cm）和 Q4（27.6cm）-在 3 种工作率条件下-80W、120W 和 160W。进行了 3×4（QF×工作率）重复测量方差分析，以分析条件之间的差异（p<0.05）。
在每个相应的工作率下，从 Q1 到 Q4，QF 的增加使峰值 KAbM 增加了 47%、56%和 56%。在每个相应的工作率下，从中侧 PRF 从 Q1 到 Q4 增加。与 QF 增加相关的是，髌股关节角度和运动范围减小。垂直 PRF、膝关节伸展力矩、矢状面峰值膝关节角度或运动范围没有观察到变化。
QF 的增加增加了峰值 KAbM，提示膝关节内侧间隙的负荷增加。在使用固定自行车进行运动或康复目的时，QF 调节可能会影响额状面关节的负荷。
