Functional cortical changes associated with shoulder instability – A systematic review
Background: Glenohumeral joint (GHJ) instability is associated with structural deficits and/or alterations in sensory and motor processing however, a proportion of patients with GHJ instability fail to respond to surgical and rehabilitative measures. This systematic review aimed to establish if functional cortical changes occur in patients with GHJ instability. Methods: AMED, CINAHL, Cochrane Central Register of Controlled Trials (CENRAL), Embase, Medline, PEDro, Pubmed, PsychINFO and Scopus were searched to 25th April 2019. Randomised controlled trials and non-randomised trials were included and quality was appraised using the Downs and Black tool. Results: 1279 records were identified of which five were included in the review. All studies showed altered cortical function when comparing instability patients with healthy controls and included areas associated with higher cortical functions. Discussion: The findings of this systematic review offer some insight as to why interventions addressing peripheral pathoanatomical factors in patients with GHJ instability may fail in some cases due to functional cortical changes. However, data is of moderate to high risk of bias. Further high-quality research is required to ascertain the degree of functional cortical changes associated with the type and duration of GHJ instability.