Effects of external pelvic compression on isokinetic strength of the thigh muscles in sportsmen with and without hamstring injuries

Abstract

Objectives: To investigate whether application of a pelvic compression belt affects isokinetic strength of the thigh muscles in sportsmen with and without hamstring injuries.

Design: Randomized crossover, cross-sectional.

Methods: Twenty sportsmen (age 22.0±1.5 years) with hamstring injuries (hamstring-injured group) and 29 (age 23.5±1.5 years) without hamstring injuries (control group) underwent isokinetic testing of the thigh muscles. Testing included five reciprocal concentric quadriceps and hamstring contractions, and five eccentric hamstring contractions at an angular velocity of 60°/s, with and without a pelvic compression belt in randomized order. The outcome measures were average torque normalized to bodyweight for terminal range eccentric hamstring contractions and peak torque normalized to bodyweight for concentric quadriceps, concentric hamstring and eccentric hamstring contractions.

Results: There was a significant increase in normalized average torque of eccentric hamstring contractions in the terminal range for both groups (p≤0.044) and normalized peak torque of eccentric hamstring contractions for injured hamstrings (p=0.025) while wearing the pelvic compression belt. No significant changes were found for other torque variables. Injured hamstrings were weaker than the contralateral uninjured hamstrings during terminal range eccentric hamstring (p=0.040), and concentric hamstring (p=0.020) contractions recorded without the pelvic compression belt. However, no between-group differences were found for any of the investigated variables.

Conclusion: Wearing the pelvic compression belt appears to have a facilitatory effect on terminal range eccentric hamstring strength in sportsmen with and without hamstring injuries. Future investigations should ascertain whether there is a role for using a pelvic compression belt for rehabilitation of hamstring injuries.

Keywords: Athletic injury; Muscle strength dynamometer; Orthotic devices.