Gravity effect on the isokinetic peak torque and hamstring to quadriceps ratios in elite basketball, volleyball and soccer players

The aim of this study was to investigate the influence of corrected and uncorrected gravity of quadriceps and hamstring peak torques and hamstring to quadriceps ratio (H/Q) in low and high angular velocities. Forty-five sport players of first division teams (basketball, n=16; volleyball, n-14; and soccer, n=15) participated in this study. Peak torque values were measured using a Cybex II dynamometer in both quadriceps and hamstring muscle groups at angular velocities of 12, 60, 180 and 300degrees-s(-1). Gravity corrected and uncorrected peak torques were recorded with a special computer program. The results indicate that the peak torque of quadriceps was higher with corrected gravity and lower with uncorrected gravity (180, 300degrees-s(-1) p<0.001). The peak torques of hamstrings, however, were lower with corrected gravity and higher with uncorrected gravity (12, 60, 180 and 300&DEG;.s(-1) p<0.001). The H/Q ratio with corrected gravity was maintained as the angular velocities increased (12degrees.s(-1)-52.3%,300degrees.s(-1)-51.4%). On the contrary, the H/Q ratio with uncorrected gravity increased as the angular velocities increased (12degrees.s(-1)-66.9%, 300degrees.s(-1)=83.3%). The results indicate that there is a need to measure the peak torque and the H/Q ratio with corrected gravity. The results measured with uncorrected gravity can underestimate the quadriceps peak torque values and can overestimate the hamstring peak torque values.