EFFECT OF PRELOAD AND RANGE OF MOTION ON ISOKINETIC TORQUE IN WOMEN

The purposes of this study were to compare the effects of two preload settings (0 N, 75 N) and two ranges of motion (5-90-degrees-ROM, 25-70 -degrees-ROM) on torque output of the knee musculature. Twenty females were randomly assessed for isokinetic concentric (CON) and eccentric (ECC) torque of the knee extensor (EXT) and flexor (FLEX) musculature at a velocity of 1.62 rads.s-1. Two four-way ANOVAs (muscle x mode x r ange of motion x preload) revealed significant differences in average torque between the preload and range of motion conditions (CONEXT: 5-9 0-degrees-ROM, 75 N = 74.3 +/- 17.2 Nm; 5-90-degrees-ROM, 0 N = 68.3 /- 17.2 Nm; 25-70-degrees-ROM, 75 N = 79.0 +/- 13.0 Nm; 25-70-degrees- ROM, 0 N = 71.5 +/- 20.8 Nm) (ECCEXT: 5-90-degrees-ROM, 75 N = 85.6 +/ - 28.6 Nm; 5-90-degrees-ROM, 0 N = 82.8 +/- 27.8 Nm; 25-70-degrees-ROM , 75 N = 97.7 +/- 23.4 Nm; 25-70-degrees-ROM, 0 N = 93.6 +/- 26.5 Nm) (CONFLEX: 5-90-degrees-ROM, 75 N = 43.5 +/- 9.2 Nm; 5-90-degrees-ROM, 0 N = 43.1 +/- 5.6 Nm; 25-70-degrees-ROM, 75 N = 44.2 +/- 8.9 Nm; 25-7 0-degrees-ROM, 0 N = 41.2 +/- 8.9 Nm) (ECCFLEX: 5-90-degrees-ROM, 75 N = 56.7 +/- 16.3 Nm; 5-90-degrees-ROM, 0 N = 55.6 +/- 17.8 Nm; 25-70-d egrees-ROM, 75 N = 57.3 +/- 14.0 Nm; 25-70-degrees-ROM, 0 N = 51.8 +/- 14.0 Nm) (P < 0.05). No differences in peak torque values were observ ed. Based on the findings of this study, preload and range of motion s hould remain constant between and among subjects if average torque is used as a criterion measure.