The Effect of Pedal Crank Arm Length and Seat Height on Joint Angles in an Upright Cycling Position

Abstract

Manipulations in crank arm length and seat height have resulted in significant changes in cycling performance. To better understand how these manipulations affect cycling performance, the purpose of this investigation was to determine the effect of 5 pedal crank arm lengths (110, 145, 180, 215 and 250 mm) and 3 seat height (short, medium, and long) on joint angles (minimum, maximum, and range of motion) of the hip, knee, and ankle, as determined by 3 electrogoniomters in an upright cycling position for17 male participants. Nine 5 x 3 Repeated Measures Factor ANOVAs revealed that 35 mm increments in crank arm length from 110-250 mm resulted in a significant (p < 0.01): (1) decrement in the minimum hip and knee angle; (2) increment in the minimum ankle angle; (3) increment in the hip and knee range of motion; and (4) decrement in the ankle range of motion. It was determined that 6 cm changes in seat height from the shortest to the longest seat height resulted in a significant (p < 0.01): (1) increment in the minimum and maximum joint angle of the hip, knee, and ankle; and (2) increment in the range of motion of the knee. No significant interactions were found between crank arm length and seat height for different angle measurements (minimum, maximum, and range of motion) of the hip, knee, and ankle. In conjunction with the results of previous investigations, certain joint angle ranges result in more effective cycling performance.