Effect of seat tube angle and crank arm length on metabolic and neuromuscular responses and lower extremity joint kinematics during pedaling with a relatively lower seat height.

Abstract

The effects of the seat tube angle and crank arm length on metabolic responses, neuromuscular activation, and lower extremity joint kinematics were investigated during bicycling with a relatively lower seat height usually used for daily life. Eleven young males performed bicycling on ergometer with various seat tube angles (60°, 65°, and 70°) and crank arm lengths (127, 140, 152, and 165mm). Oxygen consumption was measured with electromyography of the knee extensor muscle, and hip, knee, and ankle joint angles. The seat height was set as the shorter than subject's trochanter height, because this study simulates pedaling a bicycle in daily life on public roads. Significantly higher oxygen consumption was noted with a 70° of seat tube angle on comparison with a 65° of seat tube angle (p < 0.05). There were no significant effects of the crank arm length on oxygen consumption (p > 0.05). From these results, the present study suggests that a shallower seat angle could help to decrease the physiological burden during bicycling with a relatively lower seat height.