The Application of Thera-band on Non-weight Bearing Leg Influence Hip Abductor Activities During Pelvic Drop Exercise in Patients With Gluteus Medius Weakness

The Application of Thera-band on Non-weight Bearing Leg Influence Hip Abductor Activities During Pelvic Drop Exercise in Patients With Gluteus Medius Weakness

Background: The weakness of the gluteus medius (GM) is associated with various mus-culoskeletal disorders. The increasing GM activity without synergistic dominance should be considered when prescribing pelvic drop exercise (PD). Isometric hip extension or flexion of the non-weight bearing leg using thera-band at the ankle during PD may influence hip abductor activities. Objects: To determine how isometric hip extension or flexion of the non-weight bearing leg using thera-band at the ankle during PD influences the activities of three subdivisions of GM (anterior, GMa; middle, GMm; posterior, GMp), tensor fasciae latae (TFL), contralateral qua-dratus lumborum (QL), and GMp/TFL, GMm/QL activity ratios in patients with GM weakness. Methods: Twenty-three patients with GM weakness were recruited. Three types of PD were performed: PD, PD with an isometric hip extension of the non-weight bearing leg (PDE), and PD with an isometric hip flexion of the non-weight bearing leg (PDF). Surface electromyogra-phy (SEMG) was used to measure hip abductor activities. One-way repeated-measures analysis of variance was used to assess the statistical significance of muscle activities and muscle activ-ity ratios. Results: GMa, GMm, and GMp activities were significantly greater during PDF than during PD and PDE (p < 0.001, p = 0.001; p = 0.001, p = 0.005; p = 0.004, p = 0.004; respec-tively). TFL activity was significantly greater during PDE than during PD and PDF (p < 0.001, p < 0.001, respectively). QL activity was significantly greater during PDF than during PD (p = 0.003). GMp/TFL activity ratio was significantly lower during PDE than during PD and PDF (p = 0.001, p = 0.001, respectively). There were no significant differences in the GMm/QL activity ratio. Conclusion: PDF may be an effective exercise to increase the activities of all three GM subdi-visions while minimizing the TFL activity in patients with GM weakness.