Aquatic physical therapy participants reported a mean reduction in pain on movement of 33% from baseline and thus demonstrated significantly less pain at 6 weeks than control participants(P?.01)(Tab.3).This finding represented a small effect size(.24)for this outcome.Seventy-two percent(26 of 36) of the intervention participants reported a global improvement in pain ; only 17% ( 6 of 35)of the control participants did so(P?.001)(Fig.2).Similarly,75%( 27 of 36) of the intervention participants reported a global improvement in physical function; only 17%( 6 of 31) of the control participants did so(P?.001)(Fig.2).Aquatic physical therapy participants were more than 12 times as likely as control participants to report global improvements in pain (OR?12.6,95%CI?4.0–39.4),corresponding to a number needed to treat of 2(95%CI?1–3),and physical function(OR?12.5,95%CI?3.9–40.2),corresponding to a number needed to treat of 2 (95%CI?1–3).