Pain trajectories and exercise-induced pain during 16 weeks of high-load or low-load shoulder exercise in patients with hypermobile shoulders: A secondary analysis of a randomized controlled trial

OBJECTIVES: To compare pain trajectories and acute exercise-induced pain over a 16-week period in patients with hypermobility spectrum disorder (HSD) undergoing high-load (HEAVY) or low-load (LIGHT) shoulder exercise.

METHODS: In this secondary analysis using data from a randomized controlled trial, we included men and women aged 18-65 with HSD and shoulder complaints >3 months. Participants were randomly allocated (1:1 ratio) to 16 weeks of HEAVY or LIGHT shoulder exercise program, performed three times weekly. The HEAVY program consisted of progressive strengthening and full range of motion exercises, while the LIGHT program included low-load exercises performed in neutral to mid-range. Pain was assessed using the numeric rating scale (NRS) before and after each exercise session. Pain trajectories were assessed using pre-exercise pain scores at the final session each week. Exercise-induced pain was evaluated as the change in pain before and after exercise, using the mean of the three sessions each week. Both outcomes were analyzed using linear mixed models.

RESULTS: Data from 64 out of 100 patients (HEAVY 34, LIGHT 30) were analyzed (80% women, mean age 39.6, mean Beighton score of 5.8). Shoulder pain was reduced by 0.89 NRS in HEAVY (95% CI 0.4 to 1.4) and 0.33 NRS (95% CI -0.25 to 0.91) in LIGHT. The between-group difference in change in pain from baseline to week 16 was 0.56 (95% CI -0.20 to 1.33, p = 0.149). There was no between-group difference in pain trajectories (group × time interaction, p = 0.321). The mean exercise-induced pain over time was similar in both groups (group × time interaction, p = 0.614), with pain below 0.5 NRS throughout the 16 weeks.

CONCLUSIONS: Pain trajectories over 16 weeks were similar in patients with HSD and persistent shoulder complaints performing high-load or low-load shoulder exercises. There was minor to no exercise-induced pain during high-load strengthening exercise, challenging previous beliefs.