Isokinetic torque levels for knee extensors and knee flexors in soccer players.

The knee extensor and knee flexor strengths were measured isokinetically (30 degrees, 180 degrees/s) and isometrically with a Cybex II device in three groups of male soccer players (national team players, n = 13; division I, n = 15; division IV, n = 180) and a group of nonsoccer players (n = 32). There were difference in strength between soccer players and nonsoccer players and between players from different divisions. Correction for body surface area did not affect the results. The knee flexor/knee extensor ratio (H/Q ratio) was significantly higher for soccer players than for nonsoccer players. The fast-speed/slow-speed ratio for knee extensors was higher for nonsoccer players and for national team players than for players from divisions I and IV.