The purpose of this study was to investigate the influence of gender, power, hand position, and ischial tuberosity (IT) width on saddle pressure during seated stationary cycling. Twenty-two experienced cyclists (11 males and 11 females) were fitted to an adjustable stationary bicycle and pedaled at 100 and 200 W in both the tops and drops hand positions. An instrumented pressure mat was used to record saddle pressure distribution. Normalized force, maximum sensor pressure, and center of pressure were computed for anterior and posterior regions of the saddle. When increasing power from 100 to 200 W, there were significant reductions in normalized force in all saddle regions and maximum pressure in the posterior region. When moving from the tops to drops hand position, centers of pressure in all regions moved forward, normalized force and maximum pressure on the posterior region decreased, and females (but not males) exhibited an increase in normalized force and maximum pressure in the anterior region. Male centers of pressure were farther forward in the anterior and total saddle regions than they were for females. Females exhibited a larger IT width than males. Interindividual differences in IT width were significantly correlated with the posterior center of pressure fore-aft location on the saddle in the tops and drops hand positions and with the width between the posterior left and right centers of pressure in the tops hand position. There are significant gender-related differences in saddle loading which are important to consider when designing saddles. These differences are especially important when riders are in the handlebar drops and more weight is supported on the anterior pelvic structures.

An understanding of normal pelvic motion during seated cycling is relevant to saddle design and bicycle fitting. In this study, we investigated the effects of gender, power, and hand position on pelvic motion throughout a pedal stroke. We also investigated whether anthropometric factors could explain any interindividual differences observed. Twelve experienced male and 14 experienced female cyclists participated. Each subject was custom fitted to a stationary bicycle and then rode the bicycle at three power outputs (100, 150, and 200 W), with their hands in the tops and drops position. The kinematics of a triad of motion-capture markers, located on posterior pelvic landmarks, were used to characterize pelvic motion. The largest angular excursions were observed in the nonsagittal planes, with the pelvis rotating internally (approximately 3 degrees ) and rolling laterally ( approximately 2 degrees ) toward the downstroke. These pelvic rotations caused the hip on the downstroke side to translate anteriorly and inferiorly. Compared with males, females exhibited greater average anterior pelvic tilt in the drops hand position (males: 21 +/- 3 degrees ; females: 24 +/- 4 degrees ; P = 0.036). Interindividual differences in pelvic motion could not be independently explained by measures of ischial tuberosity width or hamstring flexibility. However, average anterior pelvic tilt was negatively correlated with lumbar flexibility among the males (r = 0.75; P = 0.024), suggesting that this may be an important factor to consider in bicycle fitting. We observed substantial pelvic motion during seated cycling, with experienced female road cyclists exhibiting greater average anterior tilt than their male counterparts. Pelvic motion seems to arise naturally during seated cycling and should be considered when designing saddles and establishing bicycle-fitting procedures.