Strength and range of movement deficits are associated with symptom severity in people scheduled for hip arthroscopy

Background: Identifying the physical impairments associated with worse symptoms and greater functional limitations in people with hip pain could enable targeted rehabilitation programmes designed to improve quality of life. The objective of this study was to compare physical characteristics between subgroups of symptoms and functional limitation severity in individuals with hip pain scheduled for arthroscopic surgery. Methods: Hip range of motion (ROM) and muscle strength were measured in 114 individuals (48 women; aged 32 ± 8 years) with hip pain scheduled for hip arthroscopy. Pain and disability were measured with the International Hip Outcome Tool (iHOT33) subscale of Symptoms and Functional Limitation, and a cluster analysis was used to identify mild, moderate and severe subgroups. Between-group differences were then evaluated using multivariate analysis of covariance, including sex as a covariate, followed by post hoc testing. Significance was set at 0.05. Results: Lesser hip muscle strength in all directions was reported in the severe symptoms and functional limitation group compared to the mild group. Hip flexion ROM differed when comparing the moderate to both the mild and severe subgroups. Hip internal rotation did not differ between subgroups of severity. Conclusions: Individuals with hip pain and severe scores in the iHOT33 subscale of symptoms and functional limitations present with significantly lesser hip muscle strength and hip flexion ROM than individuals with moderate or mild scores. Targeted programmes to improve hip strength and flexion ROM in more severe patients may help reduce symptoms and improve function. Significance: Individuals with severe hip pain and functional limitation possess significantly lesser muscle strength and flexion ROM than individuals with moderate or mild scores.