School of Physical Education, Applied Neuromechanics Group, Federal University of Pampa, Uruguaiana, Brazil.
Sports Biomech. 2009 Nov;8(4):275-83. doi: 10.1080/14763140903414409.
This study investigated the three-dimensional (3-D) pedaling kinematics using a noncircular chainring system and a conventional system. Five cyclists pedaled at their preferred cadence at a workload of 300 W using two crank systems. Flexion/extension of the hip, knee and ankle as well as shank rotation, foot adduction/abduction, and pedal angle were measured. Joint range of motion (ROM) and angular displacements were compared between the systems. Sagittal plane ROM was significantly greater (P < 0.05) at the hip (noncircular system = 39 +/- 3 degrees; conventional system = 34 +/- 4 degrees) the knee (noncircular system = 69 +/- 4 degrees; conventional system = 57 +/- 10 degrees), and ankle (noncircular system = 21 +/- 2 degrees; conventional system = 19 +/- 4 degrees) resulting in greater pedal ROM (noncircular system = 43 +/- 3 degrees; conventional system = 37 +/- 5 degrees) while using the noncircular system. Shank rotation ROM was significantly lower (P < 0.05) while using the noncircular chainring (noncircular system = 10 +/- 1 degree; conventional system = 14 +/- 1 degree). These results support a significant effect of the noncircular chainring system on pedaling kinematics during submaximal exercise.
本研究使用非圆链环系统和传统系统调查了三维（3-D）蹬踏运动学。五名自行车手在 300W 的工作负荷下以他们喜欢的踏频使用两种曲柄系统进行蹬踏。测量了髋关节、膝关节和踝关节的屈伸以及小腿旋转、足内收/外展和踏板角度。比较了两种系统的关节活动范围（ROM）和角位移。在矢状面，髋关节（非圆系统=39 +/- 3 度；传统系统=34 +/- 4 度）、膝关节（非圆系统=69 +/- 4 度；传统系统=57 +/- 10 度）和踝关节（非圆系统=21 +/- 2 度；传统系统=19 +/- 4 度）的 ROM 显著更大（P < 0.05），导致踏板的 ROM 更大（非圆系统=43 +/- 3 度；传统系统=37 +/- 5 度），而非圆系统。使用非圆链环时，小腿旋转 ROM 显著降低（P < 0.05）（非圆系统=10 +/- 1 度；传统系统=14 +/- 1 度）。这些结果支持在次最大运动期间非圆链环系统对蹬踏运动学的显著影响。
