Bimanual Coordination in Individuals Post-stroke: Constraints, Rehabilitation Approaches and Measures: Systematic Review.

To couple or not to couple is a dilemma for the CNS when performing bimanual goal-directed actions. Numerous interacting individual and task-related constraints contribute to the issue of effective movement coordination, and their impact on the emerging actions must be inferred from valid methodologies. This is particularly important when examining coordination in individuals with stroke undergoing rehabilitation. The purpose of this review was to identify the different constraints that may impact inter-limb coupling, and the rehabilitation approaches implemented to enhance those actions. Also, the measures incorporated to examine the effects of rehabilitation methods were reviewed. A literature search was conducted using CINAHL, PubMed and PsycINFO. Following the PRISMA 2020 guidelines, 789 relevant studies were identified, with 20 articles fulfilling the established criteria. Results showed that the impact of sex, time after stroke, type of stroke, and age were not examined in any studies reviewed. In terms of task constraints, most did not examine bimanual coordination explicitly. Bimanual movement training was the most prevalent. Regarding the dependent variables, clinician-reported and performance based scales were frequently used, while only eight studies implemented kinematic analysis, and only three examined inter-limb organization. None made explicit inferences to the existing theories of inter-limb coordination. In conclusion, important individual and task constraints on inter-limb coordination were scarcely examined. Also, majority of the studies did not involve bimanual tasks, or any measures of inter-limb coupling, thus the inferences should be treated with caution. Conceptually, all studies were data driven.