Immediate changes in spinal height and pain after aquatic vertical traction in patients with persistent low back symptoms: a crossover clinical trial.

Objective: To investigate the effect of aquatic vertical traction on spinal height, pain intensity, and centralization response compared with a land-based supine flexion position for patients with low back pain and signs of nerve root compression.

Design: Single-blind, repeated-measures crossover design.

Setting: Outpatient physical therapy clinic.