Background
Approximately 10% of patients seen in sports medicine clinics present with hip and/or groin pain, many chronic in nature.43 Extremes of hip motion—excessive stiffness or flexibility—may predispose patients to muscle and tendon injuries.
Hypothesis/Purpose: The purpose of this meta-analysis was to characterize sex-related differences in hip range of motion (ROM), including flexion, extension, abduction, adduction, internal and external rotation.
Study Design: Meta-Analysis
Methods
A systematic search of three medical literature databases was performed (PubMed, CINAHL, Embase). Search terms related to hip, pelvis, ROM, kinematic, men, and women. Studies reporting sex-specific data on hip ROM in healthy, uninjured adults were included. Data were extracted and reviewed independently by two authors. To generate mean differences in hip ROM, a DerSimonian and Laird random-effects model was used. Effect sizes were pooled for each hip ROM exercise: flexion, extension, abduction, adduction, internal rotation, and external rotation. Subgroup analyses compared hip ROM by physical activity group: passive static ROM, 1-leg hop or jump, 2-leg hop or jump, 2-leg drop landing, 1-leg squat, 2-leg squat, walking, and jogging/running.
Results
Thirty-eight studies with 3,234 total subjects were included: 1,639 (50.1% females) with a mean age of 25.3 years. An effect difference was considered statistically significant if p<0.05, and positive effect sizes represent greater ROM in females. Females were found to have significantly greater hip flexion (mean difference=2.90), adduction (mean difference=3.22), and internal rotation (mean difference=2.90) compared to their male counterparts. Females were also found to have significantly greater passive static abduction (mean difference=2.85) and passive static external rotation (mean difference=3.50). In contrast, males were found to have significantly greater flexion in 2-leg hop or jump (mean difference=-9.08) and extension in walking (mean difference=-3.97). No differences were found between sexes in 2-leg squat for any ROM values.
Conclusion
Females are significantly more flexible at the hip joint, while performing a variety of exercises in comparison to their male counterparts. These differences in hip ROM may influence the incidence and mechanism of injuries that males versus females endure, which may guide prospective studies aimed at establishing the optimal muscle-tendon contraction length for male and female athletes for injury prevention programs