Bimanual Coordination After Incomplete Cervical Spinal Cord Injury.

This thesis examines unimanual and bimanual prehension in people with an incomplete cervical Spinal Cord Injury (icSCI) when compared to non-injured younger adults (YA) and older adults (OA). Quantifying control changes following icSCI will help to guide rehabilitation to improve arm and hand function, which is the main priority for rehabilitation following injury to the cervical spinal cord. Using 3D kinematic and surface EMG analysis, eighteen participants with an icSCI, sixteen YA and sixteen OA were examined, in three studies, when reaching and grasping objects, varying in distance and size, in unimanual and bimanual conditions. Kinematic data showed that participants with an icSCI produced unimanual and bimanual movements of a longer duration and lower peak velocity, with an increased reliance on the deceleration and final adjustment phase when compared to non-injured participants. With regards to the grasp phase, participants with an icSCI produced maximum grasp aperture earlier in the movement and with temporal dissociation between the transport and grasp phases. Participants with an icSCI also showed novel muscle activity patterns when compared to non-injured participants, suggesting that neuroplasticity of spared fibres had occurred in the acute stages of the injury. Object distance and object size influenced both the transport and grasp phases of unimanual and bimanual prehension, resulting in control differences between participants with an icSCI and non-injured participants e.g. longer movement time and increased reliance on the final adjustment phase when reaching to large objects. Despite bilateral deficits of the arms and hands, participants with an icSCI showed evidence for retaining a level of bimanual coordination, such as using the final adjustment phase to improve synchrony between the limbs. This supports the integration of bimanual movements into rehabilitation in order to improve arm and hand function, as well as the performance of activities of daily living, which are often bimanual in nature.