Hip Strength and Range of Movement Are Associated With Dynamic Postural Control Performance in Individuals Scheduled for Arthroscopic Hip Surgery.

Study Design Cross-sectional. Background Hip pain is associated with reduced muscle strength and range of movement (ROM). These impairments may contribute to decreased postural stability and balance. The Star Excursion Balance Test (SEBT) is a reliable and valid method to measure dynamic postural control. Objectives To evaluate the association between SEBT performance and hip strength, hip ROM, trunk endurance, and group characteristics in individuals with hip pain. Methods One hundred eleven individuals with hip pain, scheduled for arthroscopic hip surgery, were matched with 62 healthy controls. Hip ROM and muscle strength, trunk endurance, and SEBT reach were measured prior to surgery. Data were analyzed for between-group differences using t tests, and associations between SEBT reach and hip strength, hip ROM, and population characteristics were evaluated with Pearson correlation coefficients and stepwise backward regression analyses. Results Star Excursion Balance Test performance (P<.01), hip strength (P<.01), and hip ROM (P<.05) were lower in the presurgery group compared to controls. In the presurgery group, when adjusted for height and weight, hip flexion strength and internal rotation ROM accounted for 44% of the variance in anteromedial SEBT reach. In the posteromedial direction, hip adduction strength and sex accounted for 53% of the variance. For the posterolateral direction, hip adduction and internal rotation strength accounted for 46% of reach variance. Conclusion The individuals who were scheduled for arthroscopic hip surgery were significantly weaker, had less hip mobility, and had reduced dynamic balance compared to controls. In this population, dynamic balance performance was associated with various hip strength and ROM measurements in a direction-specific manner. J Orthop Sports Phys Ther 2018;48(4):280-288. doi:10.2519/jospt.2018.7946.