Exercise Focused on Multiarticular Movement to Improve Muscle Activity During Gait and Single-leg Standing for Participants with Hip Osteoarthritis by Using Electromyogram and Three-dimensional Motion Analysis

[Purpose] We investigated how two types of exercise affect walking and single-leg standing in people with hip osteoarthritis (OA) using surface electromyogram (EMG) and three-dimensional (3D) motion analysis system. [Subjects and Methods] Participants were 18 female diagnosed as having hip OA. We defined hip abduction movement with a tube band wrapped around the thigh as monoarticular- (Mono-) group and the group using resisted joint extension with rotation movement as multiarticular- (Multi-) group. EMG measured the activity of the gluteus maximus (GMax) and gluteus medius (GMed) of affected side during 10 meters gait and single-leg standing on affected side. 3D motion analysis calculated the total locus length (TL) of anterior superior iliac spine (ASIS) of affected side during single-leg standing. These results were analyzed by t-test. [Results] After each exercise, %IEMG of GMax in Mono-group showed a significant decrease during the stance phase. In Multi group, GMax and GMed were significantly increased during the stance phase, whereas GMax was significantly decreased during the swing phase. TL during single-leg standing in Multi group decreased significantly. [Conclusion] These results indicate that exercise focusing on multiarticular movement improves muscle activity and stability in relation to daily activities.