The role of spinal manipulation has been discussed in previous study which compared the clinical efficacy of spinal manipulation against microdiskectomy in patients with sciatica secondary to lumbar disc herniation. According to this study, the pain, disability and life quality of both groups in 12-week period had no significant difference that chiropractic spinal manipulative treatment could be considered as a primary treatment. However, comparison among the effect of spinal manipulation, physical therapy, and surgery has not been conducted before. Therefore, the purpose of this study is to compare the effect of spinal manipulation, physical therapy, and surgery in the treatment of lumbar spinal stenosis.