Pain-Free Versus Pain-Threshold Rehab in a Randomized Trial

Most guidelines allow rehab only in the complete absence of pain, a rule Järvinen and colleagues admitted lacked a firm scientific basis. Drawing on the pain monitoring models of Thomeé and Silbernagel, Jack's group tested a limit of 4 out of 10 in a double-blind trial of 43 males, mostly Australian Rules footballers. Both groups did the same strength protocol and a walk-jog-walk to run-sprint-run running progression, supervised twice weekly until return to play criteria were met. Median time to clearance was 15 days pain free and 17 days pain threshold, with no meaningful difference. The pain threshold group had fewer residual isometric strength deficits (25% against 50%), larger gains in eccentric knee flexor strength and a larger drop in Tampa Scale of Kinesiophobia scores. One exacerbation occurred during sprinting. Re-injuries were two per group, but three of the four came in athletes cleared within two weeks, suggesting minimum healing timeframes or more sensitive return to play criteria.