Pain is a major determinant of impaired performance in standardized active motor tests. A study in patients with fracture of the proximal humerus

Abstract

We have followed the recovery of motor performance and the subsidence of pain for one year in 12 patients after fracture of the proximal humerus. Performance scores during standardized active motor tests were recorded 3, 8, 16, 24, and 52 weeks after injury, and the pain ratings during each of three manoeuvres were assessed on a modified Borg verbal scale. The manoeuvres were: Hand in Neck, Hand in Back, and Pour out of a Pot. In a cross-sectional analysis of data obtained 3 weeks after injury, significant correlations were found between movement-induced pain and impairment of performance in all three tests. A multivariate analysis indicated a strong association between decreasing pain and increasing performance and this was significant after elimination of the influence of healing as measured by time. In contrast, the association between time and increasing performance, after eliminating of the influence of decreasing pain, was weak and non-significant. It is concluded that pain is a major determinant of impaired performance after fracture of the proximal humerus, and that performance scores in standardized active motor tests are inversely correlated with the amount of movement-induced pain.