James E. Graves, Michael L. Pollock, Scott H. Leggett, David M. Carpenter, Cecily K. Fix, and Michael N. Fulton
The purpose of this study was to evaluate the effect of limited rangeofmotion (ROM) resistance training on the development of lumbar extension strength through a 72° ROM. 33 men and 25 women (age = 30 ± 11 yr) were randomly assigned to one of three training groups or a control group (C; n = 10) that did not train. Training was conducted once per week for 12 wk and consisted of one set of 812 repetitions of variable resistance lumbar extensions until volitional fatigue. Group A (n = 18) trained from 72° to 36° of lumbar flexion; group B (n = 14) from 36° to 0° of lumbar flexion; and group AB (n = 16) from 72° to 0° of lumbar flexion. Prior to and after training, isometric lumbar extension torque was assessed at 72°, 60°, 48°, 36°, 24°, 12°, and 0° of lumbar flexion. Analysis of covariance showed that groups A, B, and AB increased lumbar extension torque (P 0.05) at all angles measured when compared with C. The greatest gains in torque were noted for groups A and B in their respective ranges of training but A and B did not differ from AB (P > 0.05) at any angle. These data indicate that limited ROM lumbar extension training through a 36° ROM is effective for developing strength through 72° of lumbar extension.