Gluteus Medius Activity during 3 Variations of Isometric Single-Leg Stance

Abstract

Context:Gluteus medius (GM) contraction during single-leg stance prevents the contralateral pelvis from “dropping,” providing stability for lower extremity motion.Objective:To determine which combination of hip rotation and abduction exercise results in the greatest activity of the GM and whether the GM responds to increased loads in these exercises.Design and Setting:Repeated measures, laboratory.Subjects:20 healthy volunteers.Interventions:Resistance (2.26 and 4.53 kg) was provided to 3 variations of a single-leg-stance exercise: hip abduction only, abduction-internal rotation (ABD-IR), and abduction-external rotation.Measurements:Muscle activity was recorded from the anterior and middle portions of the GM using surface electromyography.Results:ABD-IR produced the most activity in the anterior and middle sections of the GM muscle. The 4.53-kg load produced significantly more activity than the 2.26-kg load (P< .05).Conclusions:The GM is most active when performing abduction and internal rotation of the hip. This information could be used to develop GM-strengthening exercises.