Mechanical analysis of the Nautilus leg curl machine

The present study assessed the capability of the Nautilus leg curl machine to reflect changes in the isokinetic resistance torque offered to the user commensurate with the human torque pattern generated by the knee flexor muscle group. An averaged isokinetic torque pattern was determined from the exercise machine and from a subject pool (N = 20) of physically active men performing prone knee flexion at two angular velocities (30 degrees/s and 60 degrees/s). The torque patterns of the exercise machine and the subject pool were expressed mathematically. Analysis of the linear regression coefficients established that the resistance torque pattern of the exercise machine was not similar to that of the subject pool (p less than .001). It was concluded that the present exercise machine system did not adequately alter the weight-stack load to provide a resistive torque suited to the biomechanical capabilities of the knee flexors under the two isokinetic conditions studied.