Enhanced muscle activity during lumbar extension exercise with pelvic stabilization

The purpose of this study was to investigate whether pelvic stabilization affects multifidus (MF) and iliocostalis lumborum (IL) muscle activities during dynamic extension exercise. Nine males (age, 25.1±6.3 yr; height, 176.6±2.4 cm; body mass, 74.9±6.7 kg) performed an isometric lumbar extension strength test and dynamic exercise in an upright seated position with or without pelvic stabilization. The electromyography and muscle strength of the MF and IL muscles were measured when the subjects performed the isometric lumbar extension strength test at the trunk angle 110°, 146°, and 182°. In addition, the trunk extensor muscle activities were measured using 50% muscle strength of maximum isometric strength during a dynamic trunk extension exercise. The MF and IL muscle activities were significantly higher at 110°, 146°, and 182° with pelvic stabilization than that without pelvic stabilization during the isometric lumbar extension strength test (P<0.05) and the dynamic exercise (P<0.05). These results suggest that the lumbar extension exercise with pelvic stabilization may be more effective for MF and IL muscle activity compared to that without pelvic stabilization.