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The left/right judgment task (LRJT) is the most commonly used method of assessing motor imagery performance. Abnormally long response times are thought to reflect delayed processing of body/spatial representations, and poor accuracy is thought to reflect disrupted cortical proprioceptive representations or body schema. Slower and less accurate responses on the LRJT have been reported in a variety of chronic musculoskeletal pain conditions. To date, no systematic review of the literature has been conducted to assess if altered motor imagery performance as measured by the LRJT is characteristic of all chronic musculoskeletal pain conditions. Therefore, the aim of this study was to conduct a comprehensive systematic review and meta-analysis of the literature to answer the following question: Do people with chronic musculoskeletal pain have impaired left/right body part judgment? Twenty-five studies (2,266 participants) including a range of chronic pain populations who undertook an LRJT were identified from searches of 8 electronic databases from inception to March 2017. Results indicate that chronic musculoskeletal pain conditions affecting the limbs and face (P ≤.01) are associated with altered motor imagery performance as measured by the LRJT. Perspectives: This review synthesizes evidence of altered motor imagery performance using the LRJT across chronic musculoskeletal pain conditions. Consistent evidence was found for altered motor imagery performance in peripheral pain conditions, but evidence was less consistent for axial conditions. Treatment to restore a normal body schema may be beneficial in chronic limb and facial pain. Refereed/Peer-reviewed

Refereed/Peer-reviewed

Background: Disruption of cortically-held working body schema has been associated with a variety of pain conditions. A motor imagery technique - the left right judgement task (LRJT) - has been used as an indirect assessment of the integrity of the working body schema. To date there is no LRJT specifically designed to investigate the body schema of persons with shoulder pain. Objectives: To develop a shoulder specific LRJT and assess its validity and reliability. Design: Cross-sectional repeated measures. Methods: Shoulder images were developed representing the shoulder in a variety of postures of graded complexity/awkwardness and degree of rotation. These images were digitally mirrored to represent both left and right shoulders. Participants viewed the images on a computer and determined whether images were of a left or right shoulder. Results: 1413 participants were recruited worldwide and performed the shoulder LRJT (laterality judgement). Mean response time (SD) for the task was 1738(741) ms. Mean accuracy (SD) was 93.5(9.2)%. Chronbach's Alpha for shoulder image response times was 0.95. Participants were fastest responding to images of simple postures and slowest to images corresponding to the more awkward postures (mean difference 520 ms, 95%CI 469–570 ms). Participants were fastest responding to the least rotated images and slowest responding to inverted images, (mean difference 981 ms, 95%CI 919–1043 ms). Conclusions: The shoulder specific LRJT proved to be highly reliable. Response times increased with complexity and rotation of images, implying a motor imagery strategy was used to complete the task, validating the task as a measure of shoulder joint implicit motor imagery. Abnormal performance cut-offs for age were reported. This result will enable further research examining the relationship between shoulder pain and body schema. Refereed/Peer-reviewed