Muscle torque changes caused by inertial exercise training.

Inertial exercise is a unique form of muscle loading with minimal data available regarding its use or efficacy. The purpose of this study was to describe a standardized clinical training program for inertial exercise using the Impulse system and to experimentally examine the influence of an inertial training program on muscle torque performance. The biceps brachii of 40 healthy subjects were pretested and posttested on the Lido Active dynamometer at 60 and 120 degrees/sec using the continuous passive motion mode. Subjects were randomly assigned to a control or training group. The training group exercised only the nondominant arm three times per week for 5 weeks on the Impulse system. Statistical analysis of peak torque measures between pretests and posttests of muscle torque was performed using a repeated measures analysis of variance design of one between-group (control vs. trained group) and three-within group (speed, arm, and movement; eccentric vs. concentric) factors. Posttraining peak torque measures for both the concentric and eccentric modes of exercise at 60 degrees/sec and for the eccentric mode at 120 degrees/sec were statistically significant at the p < .05 level. Complaints of muscle fatigue occurred during early training sessions, with no injuries and only minimal soreness reported. Inertial training appears to be an effective form of clinical muscular training that is measurable by muscle torque assessment.