Neuroscience findings on coordination of reaching to grasp an object: implications for research

Knowledge of how damage to brain regions and pathways affects central nervous system control of coordination of reach-to-grasp (RTG) following stroke may not be sufficiently used in existing treatment interventions or in research that assesses their effectiveness.

To review current knowledge of motor control of coordination of RTG and discuss the extent to which this information is being used in research evaluating treatment interventions.

This review (1) summarizes the current knowledge of motor control of RTG coordination in healthy individuals, including speculative models and structures of the brain identified as being involved; (2) summarizes evidence of RTG coordination deficits in people with stroke; (3) evaluates current interventions directed at retraining coordination of RTG, including a review of the extent to which these interventions are based on putative neurobiological mechanisms and reports on their effectiveness; and (4) recommends directions for research on treatment interventions for coordination of RTG.

Functional task-specific therapy, electrical stimulation, and robot or computerized training were identified as treatments targeted at improving coordination of RTG. However, none of the studies reporting the effect of these interventions related results to individual brain regions affected, and neurobiological mechanisms underlying improved performance were only minimally discussed.

Research on treatment interventions for coordination of RTG needs to combine measures of interruption to brain networks and how remaining intact neural tissue and networks respond to therapy with measures of spatiotemporal motor control and upper-limb function to gain a fuller understanding of treatment effects and their mechanisms.