Comparison of isokinetic trunk flexion and extension torques and powers between athletes and nonathletes

This study is aimed to perform and compare maximal concentric isokinetic trunk extension and flexion torques and powers between high-level athletes and a control population. In addition, the ratio of isokinetic trunk extension and flexion torques was measured, and compared between groups. Eighteen high-level male athletes and 15 male nonathletes without low back pain were recruited. Subjects performed isokinetic trunk extension and flexion at 60°/sec, 90°/sec, and 120°/sec through a maximal range of motion in a dynamometer. Trunk extension torque of athletes was significantly higher than in nonathletes at 60°/sec and 90°/sec but not at 120°/sec. Trunk extension power of athletes was significantly higher than the control group at 90°/sec and 120°/sec but not at 60°/sec. There was no difference between the athlete and nonathlete groups in respect of trunk flexion torque or power at any angular velocity. Consequently, the ratio of trunk flexion to extension strength was greater in nonathletes than in athletes. Trunk extension and flexion torques tended to decrease, and trunk extension and flexion powers tended to increase, with increasing angular velocity. High-level athletes seem to display preferentially greater trunk extension strength and power in comparison with trunk flexion strength, compared to nonathletes. This could be caused by the use of strength training exercises such as squats and deadlifts, or it may be associated with greater athletic performance.