Increased shoulder pain across an exercise session and subsequent shoulder exercise: a prospective cohort study

Background Shoulder complaints are common and the recommended first-line treatment is exercise therapy. However, it remains unknown if increased shoulder pain after an exercise session is a barrier for subsequent exercise dose, particularly in people with high fear-avoidance beliefs. Such knowledge could indicate ways to optimise shoulder rehabilitation. The aim was to examine whether increased shoulder pain across an exercise session was associated with a lower subsequent exercise dose, and if high fear-avoidance beliefs exaggerated this association. Methods We conducted a prospective cohort study using data from a randomised controlled trial in Central Denmark Region 2017–2019. Participants were employees ( n = 79) with shoulder complaints and high occupational shoulder exposures. The intervention was a home-based or partly supervised exercise programme lasting 2–3 months. Linear mixed models were used to examine the associations between change in shoulder pain and exercise dose (number of repetitions, progression level (1–3), resistance level (1–3), and time until next exercise session [days]). Results At baseline, the participants had a median pain intensity at rest of 2 on a numerical rating scale (0–10). For a 1-cm increase in pain on a visual analogue scale (0–10 cm) during an exercise session, the subsequent number of repetitions, progression level and resistance level were − 1.3 (95% confidence interval [CI] − 3.4 to 0.9), 0.0 (95% CI − 0.1 to 0.0) and − 0.0 (95% CI − 0.1 to 0.0), respectively. Likewise, the time until next exercise session was − 0.6 (95% CI − 2.4 to 1.3) days for a 1-cm increase. There were no interactions with fear-avoidance beliefs. Conclusion Increased pain across an exercise session was not associated with subsequent exercise dose, regardless of fear-avoidance beliefs, among employees with shoulder complaints and high occupational shoulder exposures. Trial registration The trial was registered at Clinicaltrials.gov 19/05/2017 (ID: NCT03159910).