Effect of trunk stabilization on quadriceps femoris muscle torque.

The purpose of this study was to determine if differences exist in angle-specific torque, torque-velocity relationships, and power-velocity relationships of the quadriceps femoris muscle group when the trunk was and was not stabilized and the starting position was varied. We calculated isokinetic torques from seven adult men while the trunk was and was not stabilized for nine combinations of velocity of movement 0, 30, and 105 degrees/sec) and starting position (40, 60, and 100 degrees of knee flexion). The results suggest that peak angle-specific torques and instantaneous power are greater when the trunk is stabilized, the increase in the trunk-stabilized torque and power was greater at the higher velocity and for the larger ranges of motion, and the testing movement should not begin beyond 30 degrees of the angle of interest.