INTRODUCTION: Limited range of motion (ROM), muscular strength deficits and fatigue have been found to be epidemiological risk factors for muscular injuries to the hip. The purpose of this study was to observe the changes in hip isokinetic peak torque and ROM during a soccer-specific fatigue test.

METHODS: Fourteen male high school soccer players (mean age, 17.4 <±>y 1.2years; body mass, 77.8<±>y 8.8 kg; height, 181.9<±> y 8.0 cm) completed an intermittent treadmill protocol designed to replicate the fatigue experienced during a soccer match. At five intervals (before exercise and at 20 minute intervals throughout the treadmill test), hip ROM and hip flexor torque were measured. Isokinetic hip flexor strength was recorded at speeds of 60, 180, and 300 deg/s for three repetitions at each speed using a Biodex dynamometer. Hip flexor ROM was measured using a long armed goniometer during active and passive hip extension.

RESULTS: Peak concentric isokinetic hip flexor torque was maintained throughout the exercise duration, regardless of speed. Passive and Active ROM significantly decreased between pre and post tests (p=0.01) and (p=0.0001), respectively.

CONCLUSION: Active ROM decreased across the exercise protocol. This suggests increased susceptibility to injury, especially towards the later stages of a soccer match.