LAUSR

CONTEXT Weakness of the gluteus medius and the gluteus maximus is associated with a variety of musculoskeletal disorders. However, activation of synergist muscles that are not targeted should be considered when prescribing side-lying hip abduction (SHA) exercises. Log-rolling positions may affect hip abductors activity during SHA. OBJECTIVES To determine the effects of log-rolling positions on the gluteus medius, the gluteus maximus, and the tensor fasciae latae activity during SHA in participants with gluteus medius weakness. DESIGN The effects of different log-rolling positions on hip abductor activity during SHA were analyzed by one-way repeated-measures analysis of variance. SETTING University research laboratory. PARTICIPANTS Twenty-one participants with gluteus medius weakness were recruited. INTERVENTIONS Three types of SHA were performed: SHA in the frontal plane with a neutral position (SHA-neutral), SHA in the frontal plane with an anterior log-rolling position (SHA-anterior rolling), and SHA in the frontal plane with a posterior log-rolling position (SHA-posterior rolling). MAIN OUTCOME MEASURES Surface electromyography was used to measure the hip abductor activity. One-way repeated-measure analysis of variance was used to assess the statistical significance of the muscle activity. RESULTS SHA-anterior rolling showed significantly greater gluteus medius and gluteus maximus activation than SHA-neutral (P = .003 and P < .001, respectively) and SHA-posterior rolling (P < .001 and P < .001, respectively). SHA-neutral showed significantly greater gluteus medius and gluteus maximus activation than SHA-posterior rolling (P < .001 and P = .001, respectively). SHA-anterior rolling showed significantly less tensor fasciae latae activation than SHA-neutral (P < .001) and SHA-posterior rolling (P < .001). SHA-neutral showed significantly less tensor fasciae latae activation than SHA-posterior rolling (P < .001). CONCLUSION SHA-anterior rolling may be an effective exercise to increase activation of the gluteus medius and the gluteus maximus while decreasing the tensor fasciae latae in participants with gluteus medius weakness.