Effect of Robot Rehabilitation Exercise Training on Motor Control After Stroke

Stroke is a leading cause of neurological disability worldwide, often causing significant weakening and paresis of the affected arm. National spending on post-stroke rehabilitation is project to expand 20% to 35% through 2010. As a new tool for therapists, robotic stroke therapy devices have the potential to be a cost-effective device aid to physical therapy and enable novel modes of exercise not currently available. While recent studies have shown chronic patients benefit from repetitive practice, it is not clear whether they improved via a reduction in impairment or increased functional compensation because there is a lack of standard treatment and scales to assess rehabilitation efficacy in chronic stroke patients. This study aims to reconcile difference performance measurements in robotic rehabilitation to assess the outcome of robotic rehabilitation training.

Arm motor control was assessed through analysis of reaching movements to targets. We derive a measure of arm motor control using functional principal components analysis of reaching trajectories (average squared Mahalanobis distance). This is a unitless measure and lower change values reflect improvement in motor control, while a higher change value reflect a worsening in motor control.

The FM is a measure of impairment that considers movement arm, wrist, hand, and coordination. Each of the 22 items is scored on a three-point ordinal scale for total score between a minimum score of 0 and a maximum score of 66. A higher score indicates a better outcome.

The ARAT tests hand and arm function and consists of 19 items in 4 domains: grasp, grip, pinch, and gross movement. Each domain contains items arranged into hierarchical order of difficulty such that success at the most difficult item of a specific subclass assumes success for all items lower in the hierarchy of the same class. Each item is scored on a four-point ordinal scale for total score between a minimum score of 0 and a maximum score of 57. A higher score indicates a better outcome.

Inclusion Criteria: Hemiparesis of the upper extremity Diagnosis of a first clinically apparent ischemic stroke at least 6 months prior to study entry Age 18 years or older Ability to sit and be active for an hour on a chair (or wheelchair) without cardiac, respiratory disturbances and/or pain. Exclusion Criteria: Inability to understand and/or follow instructions Pain in shoulder or arm Other neurological or musculoskeletal target organ disorder Inability to give informed consent personally Previous or current contracture of the upper extremity