Do Hip Joint Positioning Affects t he Maximal Voluntary Contraction o f Gl uteus Maximus, Gluteus Medius, TFL a nd Sartorius M uscles ?

Background: Functional and clinical benefits from mini invasive total hip arthroplasty (THA) are widely known. Although it relieves pain and improves quality of life, literature reveals that gait and posturographic parameters of patients undergoing THA do not reach those of the general population. An electromyography study of the hip muscles involved in the surgery (Gluteus Maximus, Gluteus Medius, TFL, Sartorius) could provide some information. But the literature in the field of electromyography assessment of muscles shows discordant methodologies. Purpose:The aim of this study was to develop a methodology to assess the maximal voluntary contraction (MVC) of Gluteus Maximus, Gluteus Medius, TFL, Sartorius muscle as a reference for normalization. Methods:30 young asymptomatic subjects participated in the study. Each realizedn8 maximal voluntary contractions of the hip muscles in variousjoint positions on 3 sessions. Results: Statistical analysis showed no difference between the 3 sessions, and between the hip positions for hip abductors as well as for hip flexors to assess the MVC. Conclusion:A single session and 1 test is enough to assess the MVC of hip abductors as well as for hip flexors.