Motor-Equivalent Intersegmental Coordination Is Impaired in Chronic Stroke.

Background. Kinematic abundance permits using different movement patterns for task completion. Individuals poststroke may take advantage of abundance by using compensatory trunk displacement to overcome upper limb (UL) movement deficits. However, movement adaptation in tasks requiring specific intersegment coordination may remain limited. Objective. We tested movement adaptation in both arms of individuals with chronic stroke (n = 16) and nondominant arms of controls (n = 12) using 2 no-vision reaching tasks involving trunk movement (40 trials/arm). Methods. In the "stationary hand task" (SHT), subjects maintained the hand motionless over a target while leaning the trunk forward. In the "reaching hand task" (RHT), subjects reached to the target while leaning forward. For both tasks, trunk movement was unexpectedly blocked in 40% of trials to assess the influence of trunk movement on adaptive arm positioning or reaching. UL sensorimotor impairment, activity, and sitting balance were assessed in the stroke group. The primary outcome measure for SHT was gain (g), defined as the extent to which trunk displacement contributing to hand motion was offset by appropriate changes in UL movements (g = 1: complete compensation) and endpoint deviation for RHT. Results. Individuals poststroke had lower gains and greater endpoint deviation using the more-affected compared with less-affected UL and controls. Those with less sensorimotor impairment, greater activity levels, and better sitting balance had higher gains and smaller endpoint deviations. Lower gains were associated with diminished UL adaptability. Conclusions. Tests of condition-specific adaptability of interjoint coordination may be used to measure UL adaptability and changes in adaptability with treatment.

Extrinsic feedback and upper limb motor skill learning in typically-developing children and children with cerebral palsy: Review.

BACKGROUND: Improvment of upper limb motor skills occurs through motor learning that can be enhanced by providing extrinsic feedback. Different types and frequencies of feedback are discussed but specific guidelines for use of feedback for motor learning in typically-developing (TD) children and children with Cerebral Palsy (CP) are not available. OBJECTIVE: Identify the most effective modalities and frequencies of feedback for improving upper limb motor skills in TD children and children with CP. METHODS: Ovid MEDLINE, Cochrane, PEDro and PubMed-NCBI were searched from 1950 to December 2015 to identify English-language articles addressing the role of extrinsic feedback on upper limb motor learning in TD children and children with CP. Nine studies were selected with a total of 243 TD children and 102 children with CP. Study quality was evaluated using the Downs and Black scale and levels of evidence were determined with Sackett's quality ratings. RESULTS: There was a lack of consistency in the modalities and frequencies of feedback delivery used to improve motor learning in TD children and in children with CP. Moreover, the complexity of the task to be learned influenced the degree of motor learning achieved. CONCLUSION: A better understanding of the influence of feedback on motor learning is needed to optimize motor skill acquisition in children with CP.

Balance and mobility in clinically recovered children and adolescents after a mild traumatic brain injury.

PURPOSE: To compare the ability of clinical balance measures to detect differences between children recovered from a mild Traumatic Brain Injury (mTBI) and healthy controls. METHODS: A cross-sectional study, with twenty-six children with mTBI and twenty-two age-matched controls was conducted. Balance was evaluated on three scales: Bruininks- Osteresky Test-second edition; Balance Error Scoring System and Community Balance and Mobility Scale, along with gait analysis of three paradigms (self-selected paced walking, obstacle crossing and tandem walking), under single and dual-task conditions, using GAITRite\scriptsize® walkway. Independent sample t-tests (α = 0.05) were used to identify group differences. Dual-Task Cost (DTC) was analyzed using repeated measures ANOVA and t-tests. Discriminant analysis predicted which balance measure best identified the groups. RESULTS: Children with mTBI performed worse on all balance scales (p< 0.05). Gait parameters were significantly better for the controls. There were no group differences on the motor and cognitive DTC. The Community Balance and Mobility Scale and gait parameters including velocity at obstacle crossing and parameters for tandem walking, best discriminated the groups. CONCLUSION: Clinical balance assessments may need to include static and dynamic measures, to capture possible performance difficulties. The inclusion of these measures will enhance clinical decision making and prevent premature return to physical activities in children with mTBI.