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

BACKGROUND: 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. OBJECTIVE: 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. METHOD: 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. RESULTS: 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. CONCLUSIONS: 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.

Kinematics of turning 180 degrees during the timed up and go in stroke survivors with and without falls history.

BACKGROUND: Community-dwelling, chronic stroke survivors are at risk of falling during turning and are more likely to sustain a hip fracture when they fall. OBJECTIVE: This study quantifies kinematic differences between stroke survivors (mean +/- SD: 38.3 +/- 31.3 months post-stroke, 59.9 +/- 10.1 years of age), with (n = 9) and without a falls history (n = 9), and age-matched healthy counterparts (n = 18) in turning coordination during the 180 degrees turn around in the Timed "Up & Go" (TUG) test. METHODS: Full-body kinematics were recorded while participants performed the 180 degrees turn around in the TUG. Dependent measures were time to turn, number of steps to turn, and measures of axial segment coordination. Result. Although participants who had a stroke and falls history took significantly longer to turn (mean +/- SD: 4.4 +/- 1.7 seconds) than age-matched controls (2.5 +/- 0.6 seconds), no kinematic differences were found in performance or in the axial segment coordination during turning that could contribute to falls history or falls risk. CONCLUSIONS: These results indicate incidences of falls during turning following stroke may not be due to impaired movement patterns but due to the many other factors that are associated with falls, such as deficits in cognitive processes--attention or central integration--and/or sensory deficits.

Seated bilateral leg exercise effects on hemiparetic lower extremity function in chronic stroke.

BACKGROUND: Bilateral arm training with rhythmic auditory cueing (BATRAC) improves hemiparetic upper extremity (UE) function in stroke. It is unknown whether a similar exercise for the hemiparetic lower extremity (LE) is effective. OBJECTIVE: The authors sought to test whether the BATRAC strategy would transfer to the legs by improving LE motor function following ten 30-minute sessions of bilateral leg training with rhythmic auditory cueing (BLETRAC). METHODS: Twenty-four chronic stroke participants, recruited from the community, were randomized to either the BLETRAC or the BATRAC intervention. Assessments were performed before (week 0) and after (week 6) training as well as 3 months later (week 18). Change in the Fugl-Meyer LE and UE subscales served as primary outcomes. Timed 10-m walk, movement parameters during treadmill walking, and a repetitive aiming task for both feet and hands were the secondary outcomes. RESULTS: Following an intention-to-treat approach, data from 21 subjects were analyzed. After training, improvements in the Fugl-Meyer LE and UE subscales tended to be better for the corresponding intervention group. The BLETRAC group also showed increases in step length during treadmill walking and performance in the repetitive foot and hand aiming tasks. No differences between the intervention groups were found at follow-up. CONCLUSIONS: This exploratory trial demonstrates that transfer of the BATRAC approach to the legs is feasible. Transient improvements of limb motor function in chronic stroke participants were induced by targeted exercise (BATRAC for the UE and BLETRAC for the LE). It may be that further periods of training would increase and maintain effects.