Abstract
Objective: Recent evidence suggests that education on the pain-relieving effects of exercise may enhance exercise-induced hypoalgesia (EIH) in healthy individuals. However, its impact in populations with osteoarthritis (OA), where EIH responses are more variable, remains unclear. This study examined whether positive pre-exercise education enhances EIH in individuals with knee OA.
Methods: A double-blind, randomized controlled trial was conducted with 42 participants allocated to either a positive pre-exercise education group (n = 21) or a control education group (n = 21). Each group received two individual education sessions 24-72 h apart. OA- and EIH-related knowledge and beliefs were assessed pre- and post-education. EIH was evaluated following a single submaximal isometric quadriceps contraction to failure by measuring changes in pressure pain thresholds (PPTs), resting pain, and pain during stepping. Group differences were analyzed using ANCOVA.
Results: The positive pre-exercise education group demonstrated greater improvements in EIH-related knowledge and beliefs compared to the control group (p = 0.001, d = 0.50, ANCOVA between-group analysis), while OA-related knowledge and beliefs remained unchanged (p = 0.34, d = 0.15). However, ANCOVA results showed no significant between-group differences in pre- to post-exercise changes in PPTs, resting pain, or pain during stepping (all p > 0.11, d = 0.04-0.25).
Conclusion: Despite enhancing beliefs about exercise-induced pain relief, positive pre-exercise education did not enhance EIH compared to control education. These findings highlight the need for alternative strategies to optimize exercise-induced pain relief in OA.