Inter-limb coordination in bimanual reach-to-grasp following stroke

Purpose. To determine the extent to which inter-limb coordination in the execution of unimanual and bimanual tasks was impaired following stroke. Methods. Thirteen stroke survivors aged 55-77 years and 13 healthy, neurologically intact participants aged 57-86 years performed a unimanual and two bimanual tasks involving the relocation of single and paired objects. Movements were recorded using electromagnetic sensors attached to the wrists and a series of micro switches placed under the objects. Main outcome measures included time to complete components of the tasks; comparison between sides; deviation of the hands from a linear trajectory; coordination of the two sides as indicated by relative phase angle. Results. Stroke survivors took longer to complete the bimanual tasks, but did not deviate from the optimal trajectories more than the healthy participants. Both groups performed unimanual tasks faster than bimanual and stroke participants were only slightly less synchronised when performing bimanual tasks. Conclusions. In conclusion, in a group of stroke patients with reasonable strength, inter-limb coordination was mildly impaired. This impairment in coordination was not due to lateral deviation of the impaired limb.