Relationship between hip muscle strength and disability in patients with nonspecific low-back pain: A cross-sectional study

Low-back pain (LBP) is reported to be single largest cause of disability worldwide. The hip is related to LBP due to its close association with the lumbopelvic region as well as the biodynamic relationship between hip joint and lumbar spine. We set out to evaluate the relationship between gluteus maximus (GMax) and gluteus medius (GMed) muscle strength and disability in patients with nonspecific (NS) LBP. We recruited 52 subjects with NSLBP and assessed maximal isometric strength of GMax and GMed using a universal digital push–pull dynamometer and the Modified Oswestry LBP Disability Questionnaire (MODQ). After adjusting for potential covariates, we found that GMax strength was not associated with MODQ scores (p = 0.06) in individuals with NSLBP. However, GMed strength was significantly associated with MODQ scores (p = 0.02) in these patients. No difference was present in gluteal muscle strength between the two sides. We found that GMed strength is significantly associated with perceived disability in individuals who suffer from NSLBP. Rehabilitation practitioners involved in managing individuals with NSLBP must screen for GMed strength and address results using appropriate interventions should weakness be found.