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).