Investigating the relationship between biomechanical parameters measured during isokinetic tests and sprint runnings

Lower limb joint moments are crucial in sprint performance. However, it remains unclear how much joint torque is needed for each sprint phase. The aim of this study is to examine the relationship between isokinetic test results of the hip and knee joint and sprint times in all acceleration phases, angular velocities of the knee and hip joint and temporospatial parameters. 15 sprinter athletes participated in our research. Athletes' sprint times were recorded by placing sensors at 5m, 10m, 20m, 30m, 45m and 60m acceleration intervals during the 60m sprint. Simultaneously, a total of 8 cameras measuring at 240 fps frame rate and high resolution were placed on both sides of the sprint lane. Two-dimensional images were processed with the Kinovea 0.9.5 program and the angular velocities of the knee and hip joint in flexion and extension of both limbs were obtained at each step. Likewise, the times spent in each contact and flight phase were obtained. Isokinetic tests were performed in concentric flexion and extension movements at speeds of 60 and 240 deg/s in both knee and hip joints. Flexion relative torque of the knee joint showed a high correlation with 30-60m sprint time at r=-0.718 (p<0.01). Flexion torque of the hip joint showed a high correlation with 30-60m sprint time at r=-0.621 (p<0.01). Non-dominant limb contact phase times showed a very high correlation with 5-20m sprint times at r=0.839 level and 45-60m sprint times at r=0.808 level (p<0.01). Non-dominant limb contact phase time in the 5-20m and relative flexion torque at 240 deg/s showed a high correlation at r=-0.649 (p<0.01). During the flight phase between 0-5m, the hip extension speed on the starting leg side showed a high correlation with the extension torque produced at 60 deg/s at r=0.721 and with the speed at 240 deg/s at r=0.713 (p<0.01). Comparing sprint times between 5-20m and 10-30m with the eccentric flexion speed of the hip during the contact phase on the opposite side of the starting leg, high correlations were found at the levels of r=0.690 and r=-0.730, respectively (p<0.01). As a result, it was determined that isokinetic torque values in the knee and hip joints were related to sprint performance. It has been determined that angular velocities and contact phase times are the determining factors in sprint performance. However, when evaluating sprint performance, test results such as the time to peak torque, the power produced and its duration should also be taken into account.