Proprioception : how is it affected by shoulder pain? A systematic review

Introduction: Proprioception encompasses the submodalities of joint position sense (JPS), kinesthesia, sense of force, and velocity. Owing to the vast mobility of the shoulder, it heavily relies on an intact sense of proprioception. Moreover, shoulder injuries are associated with a decreased sense of proprioception. What remains unclear is how shoulder proprioception is affected by pain and competing nociceptive senses. Purpose of the Study: To summarize the literature evaluating the relationship between pain and shoulder proprioception. Methods: A literature review was conducted from inception until 22 October 2018, using electronic databases (PubMed, Web of Science, Scopus, EBSCO, CINAHL, and Embase). Retrieved citations were screened for eligibility, and methodological quality was assessed using the Newcastle-Ottawa Scale (NOS). Results: Eleven studies were included (n = 447 participants with shoulder pain, n = 20 with experimentally induced pain [EIP]/n = 600 painful shoulders and n = 20 [EIP]). The mean methodological quality of the studies was good (76%). Five studies investigated active JPS, four investigated passive JPS, six investigated kinesthesia, sense of force was measured in one study, and no study investigated sense of velocity. There is moderate evidence for impaired kinesthesia and low evidence for reduced sense of force among painful shoulders. Conflicting evidence is seen for the other proprioceptive submodalities. Conclusion: The overall impact of pain on shoulder JPS remains unclear, while moderate evidence for an affected sense of kinesthesia is possible. There is low evidence for an impaired sense of force among painful shoulders. Standardization between studies is lacking, limiting the range of our conclusions. Further investigation is required into well-controlled and pain-induced studies to better understand the influence of pain on shoulder proprioception