Electromyographic Changes in Trunk Muscles During Graded Lumbar Stabilization Exercises

BACKGROUND: Lumbar stabilization exercises are effective for the treatment of patients with low back pain. However, personalized exercise programs are required to facilitate more efficient treatment, as each individual exhibits the different characteristics of the trunk muscles and pain. OBJECTIVE: To determine the effects of graded lumbar stabilization exercises on the trunk muscles in healthy individuals, using surface electromyography. DESIGN: A cross-sectional prospective study. SETTING: Outpatient pain clinic. PARTICIPANTS: Ten healthy male participants without low back pain were recruited on a volunteer basis. METHODS: Four common lumbar stabilization exercises were selected, including the curl up, dead bug, Superman, and bird dog exercises. Each exercise was divided into 5 intensity levels, with participants performing all exercises at each intensity level, to a total of 20 exercises. Electromyographic changes in the trunk muscles according to intensity level were analyzed. MAIN OUTCOME MEASUREMENTS: Using superficial electromyography, the peak amplitude and area under the curve for each of the rectus abdominis (RA), external oblique abdominis (EO), multifidus (MF), and erector spinae (ES) muscles were measured. RESULTS: In general, as the level of intensity increased, the activity of the related lumbar stabilizing muscles also increased significantly (P < .05). Specifically, the peak amplitudes of the RA (P = .008) and EO (P < .001) were increased during the curl up exercise, whereas the peak amplitudes of the MF (P < .001) and ES (P = .002) were increased during the bird dog exercise. The prolonged exercise duration of the Superman exercise increased the mean area under the curve of MF, ES, and RA (P < .001). CONCLUSIONS: Using a graded exercise program, an appropriate level of exercise intensity can be prescribed and modulated according to patient tolerance and physical ability. Therefore, a graded lumbar stabilization exercise program may represent an effective way to strengthen the lumbar stabilizing muscles in patients with low back pain.