Association between abductor muscle strength and functional outcomes in hip-fractured patients: a cross-sectional study

OBJECTIVES: To explore associations between abductor strength and functionality in hip-fracture patients. METHODS: Ninety-six participants (70-84 years) followed a 12-week physiotherapy programme emphasizing hip abductor strengthening. The abductor’s isometric strength, the hip strength asymmetry (HSA), expressing the ratio of abductor strength in the fractured versus the contralateral hip, and the patients’ functional level were recorded 3 months post-intervention. Functionality was assessed using the Timed Up & Go (TUG) test and the Lower Extremity Functional Scale (LEFS-Greek). RESULTS: Abductor isometric strength and HSA were correlated negatively with TUG test (Pearson’s r: -0.881 and -0.810, respectively; p<0.001) and positively with LEFS-Greek (Spearman’s ρ: 0.668 and 0.404, respectively; p<0.001). Of all independent variables examined, abductor isometric strength was the main predictor of functional capacity, being strongly and directly associated with a faster TUG test time (p<0.001) and a better LEFS-Greek score (p<0.001). Abductor’s isometric strength and age explained 79.0% and 49.5%, whereas HSA and age explained 69.7% and 41.9% of TUG and LEFS-Greek variance, respectively. CONCLUSIONS: Abductor isometric strength was the main predictor of hip-fracture patients’ functionality, strongly enhancing the measured functional outcomes. Hip abductor strengthening appears to be of major clinical importance and may contribute significantly to the functional rehabilitation of hip-fractured patients.