To compare the treatment effects of back exercise on functional status, spinal mobility, SLR, pain severity, and treatment results satisfaction, and to determine whether spinal exercises during the low back pain reduces recurrent episodes of back pain. 1. Flexion and extension exercise groups did not differ in any outcome over 4weeks. After 1week, both exercise groups had reduced disability score, a higher proportion returning to work, and fewer subjects with a positive SLR compared with the control group. 2. There was no difference among groups regarding recurrence of low back pain after 6~12 months. 3. There was no difference for any outcomes between the flexion or extension groups. However, either exercise was slightly more effective than no exercise when patients with low back pain were treated.