Hip flexibility and strength measures: Reliability and association with athletic groin pain

Objective: Groin pain commonly affects football players and can be associated with prolonged recovery periods. Understanding the relationship between groin pain and reliable measures of hip flexibility and strength may facilitate the development of optimal rehabilitation and prevention strategies. In this study, the reliability and association with athletic groin pain of hip flexibility and strength measures were investigated. Methods: A cohort of 29 football players (15-21 years) participating in junior elite competitions (Australian Rules football and soccer) were recruited. The intra-rater reliability (n = 13) and inter-rater reliability (n = 12) of various hip flexibility (bent knee fall out test, hip internal rotation, hip external rotation) and strength (hip abduction, hip internal rotation, hip external rotation, hip adduction (squeeze test)) measures were investigated using intraclass correlation coefficients (ICC). Reliable hip flexibility and strength measures were compared between football players with (n = 10) and without (n = 19) groin pain. Results: The bent knee fall out test, hip internal rotation flexibility and the squeeze test demonstrated acceptable (ICC>0.75) intra-rater and inter-rater reliability, while hip external rotation flexibility and hip abduction strength demonstrated acceptable intra-rater but not inter-rater reliability. Hip internal and external rotation strength tests were not found to be reliable. Football players with groin pain had significantly reduced force production on the squeeze test (p>0.05). Conclusion: Several hip flexibility and strength measures were found to be reliable. Only the squeeze test discriminated between football players with and without groin pain.