Is It Time to Step outside the Laboratory? The Feasibility of Field-Based Examination of Exercise-Induced Hypoalgesia in Elite Badminton Athletes with and without Knee Pain.

Aim: To investigate the feasibility of testing exercise-induced hypoalgesia (EIH) in a field setting. The effect of knee pain on EIH was also explored.

Design: Within-group pre-post design.

Materials and methods: Fourteen athletes (8 male, 6 female) competing at an international level in badminton were tested on the sideline during an in-season training session. Participants completed questionnaires and a single leg decline squat to evaluate the presence of knee pain. A blinded examiner measured PPT over the quadriceps muscle before and after two conditions (3-minute quiet rest and 3-minute isometric wall squat).

Results: The exercise protocol was completed by 13 (93%) participants. Mean (SD) exertion was 8.4 (1.7), and mean thigh pain was 7.9 (2.0) at 3 minutes. Very high reliability was observed for PPT collected before and after rest (ICC 0.94, 95% CI 0.85, 0.98). PPT significantly increased by 22.4% (95% CI 15.1, 29.7) after wall squat but not after rest. Relative increases in PPT were similar in participants with and without knee pain on single leg decline squat (22.2% versus 22.6%, 7 participants each).

Conclusion: Simple, field-based tests of endogenous analgesia are feasible and could provide new opportunities to evaluate an athlete's risk of persistent pain.