Psychological influences predict recovery following exercise induced shoulder pain.

Predicting recovery following muscle injury can be difficult because it involves consideration of multiple factors. Our objective was to determine if psychological factors, sex, and peak pain and disability ratings could be predictive of delayed recovery following induced muscle injury. Healthy untrained volunteers (n=126; M:F 51:75) underwent a concentric/eccentric isokinetic exercise protocol on their dominant shoulder to induce fatigue, with individuals who reported pain (>0/10) at 96 h being classified as "not recovered". Individuals experiencing pain at 48 h were more likely not to be recovered (O.R.=1.62, p<0.001). Additionally, individuals with higher scores in pain catastrophizing at 48 h were more likely to experience pain at 96 h (O.R.=1.06, p<0.001). Pain duration (in days) was associated with pain scores at 48 h (β=0.385, p<0.001) and baseline anxiety (β=0.220, p=0.007). Fear of movement/re-injury at 96 h was found to be associated with pain catastrophizing at 48 h (β=0.537, p<0.001) and baseline levels of fear of pain (β=0.217, p=0.004). This study provides preliminary evidence that higher pain levels and pain catastrophizing following acute muscle injury are associated with poor recovery, higher fear of movement/re-injury and longer pain duration.