Loss of range of motion of the hip joint: a hypothesis for etiology of sports hernia.

Background: sports hernia is a well-recognized cause of groin pain in athletes involved in sports, especially football and rugby. Loss of range of motion of the hip joint is a possible contributory factor to stress across the symphysis pubis leading to the instability.

Methods: twenty-five athletes presenting with sports hernia were matched to age, sex, physical/sports activity and co-morbidities with twenty-five athletes without sports hernia. The range of movement of both the hips was compared in athletes of both the groups.

Results: there was marked restriction of internal rotation with the hip flexed to 90 degrees (average 17 degrees) and external rotation (average 26 degrees) in sports hernia group compared to the control group. Other movements of the hip were comparable in both the groups.

Conclusion: the study highlights observation of limitation of hip rotation with the hip flexed to 90 degrees as a possible factor in the aetiology of sports hernia. There may be an association with other pathologies of the hip such as impingement that requires further investigation. Though this study has its limitation in being a small number and a case control study, it does helps in understanding the possible mechanism of development of this condition.