Effect of Manual Force on Lumbar Side Bending Range of Motion

Objective: We evaluated the immediate changes in intervertebral motion after application of lumbar manual force. Methods: Fifteen male volunteers (aged 26–43 years) with no history of significant low back pain were recruited to participate as a study group (manual traction). Control group (without manual traction) consisted of fifteen male volunteers who are matched with age (age 21-45 years). Consenting volunteers were referred for three radiographs (neutral position, right side bending position prior to manual force and right side bending position after manual force). The L3/4 segment was chosen for manual force, which was performed by a single examiner. Frontal angular rotation of each lumbar spine segment and total lumbar spinal motion were measured radio graphically before and after manual force by a single investigator (radiologist). Within-group differences were assessed with the paired t test. Results: Analysis of the pre-and post-manual force radiographs showed a significant average increase at the L3/4 segment from 4.9° to 6.4° and an improvement in the total range of motion from 17.8° to 19.5° in the study group. No significant increase was found at the L1/2, L2/3, or L4/5 segments in the study group. In the control group, there were no significant changes in all measurements. Conclusion: These results suggest that manual force targeting the L3/4 segment results in an immediate increase in the angular motion of the L3/4 segment and improvement in total motion of the lumbar spine.