Effects of treadmill exercise with and without vertical traction on gait, pain, disability, trunk proprioception, and depression in patients with chronic mechanical low back pain: A randomized controlled trial

Introduction: Treadmill exercise may improve gait and clinical outcomes in patients with chronic mechanical low back pain (CMLBP), but the additional effects of vertical traction and partial body weight support remain unclear. This study compared treadmill exercise combined with vertical traction and partial body weight support (VT+TE), treadmill exercise alone (TE), and core stabilization exercise. Methods: Forty-five patients with CMLBP were randomly assigned to VT + TE, TE, or control groups (n = 15 each). All groups received conventional physical therapy and completed 24 sessions over 8 weeks. Body weight support in the VT + TE group was reduced from 50% to 30%. The TE group performed pain-tolerable treadmill walking, whereas controls performed self-directed core stabilization exercises. Outcomes included Timed Up and Go (TUG) performance, self-selected and fast gait speeds, pain intensity, pressure pain threshold, disability, trunk repositioning error, and depressive symptoms. Assessments were conducted at baseline, post-intervention, and 4-week follow-up. Results: Significant time-by-group interactions occurred for all outcomes. Both treadmill groups showed greater improvements than controls in TUG performance, self-selected gait speed, pain intensity, and depressive symptoms. Compared with TE, VT + TE produced greater improvements in TUG performance, self-selected gait speed, disability, and flexion and extension repositioning errors. VT + TE also improved fast gait speed more than both comparison groups at post-intervention. Improvements in pain intensity and depressive symptoms were maintained at follow-up in both treadmill groups. Conclusions: Adding vertical traction and partial body weight support to treadmill exercise may provide additional benefits for gait performance, disability, and trunk repositioning accuracy in patients with CMLBP. Interpretation is limited by the small sample size and the inability to distinguish the effects of vertical unloading from those of harness support.