Objective: To evaluate the influence of pelvic restraint on electromyographic activation (neural drive) of the lumbar extensor, gluteal, and hamstring muscles during submaximal dynamic lumbar extension in an upright seated position. Design: Randomized, balanced, crossover trial comparing the electromyographic activation of the lumbar, gluteal, and hamstring muscles during dynamic lumbar extension exercise with and without pelvic restraint. Setting: Research laboratory at a private research university. Subjects: Twelve apparently healthy men (ages 18 to 50yrs). Intervention: Dynamic lumbar extension exercises. Main Outcome Measure: Electromyographic recordings. Results: Pelvic restraint did not influence the relative activation of the lumbar, gluteal, or hamstring muscle groups (p 5 .05) during submaximal dynamic lumbar extension exercise. The relative activation of the gluteal muscles was significantly lower than that of the lumbar extensor and hamstring muscle groups. Conclusions: Pelvic restraint is not a requirement to promote neural drive to the lumbar musculature during submaximal dynamic lumbar extension exercise performed in an upright seated position. Submaximal lumbar extension exercise reduces the relative contribution of the gluteal muscles compared with a maximal voluntary isometric contraction
