Effects of attentional focus on motor training of the upper extremity using robotics with individuals after chronic stroke

For healthy individuals, research supports that adopting an external focus (thinking about the task goal) facilitates learning of motor tasks better than an internal focus (thinking about the body movements required to complete the task) for temporary performance and retention of motor skills. In contrast, little is known about the effects of attention on motor skill training for individuals after stroke. To address this gap in the literature, a randomized, repeated measures, mixed ANOVA design was used to compare the long term effects of an external focus versus internal focus of attention after a 4-week arm training protocol on the InMotion2 shoulder /elbow robot. Methods: Thirty participants with moderate-to-severe arm impairment were randomly assigned to either an external focus or internal focus group, and matched for sample size, level of arm impairment, and training dosage. Attentional focus and level of arm impairment were the between group factors, and time was the within group factor. Smoothness and joint independence (kinematic outcomes), Fugl-Meyer Assessment, and Wolf Motor Function Test measured change in arm status at baseline, discharge, and at 4-week follow up. Participants in both groups improved significantly on all outcome measures from baseline to discharge and maintained those changes at 4-week follow up regardless of group assignment [smoothness, F(1.49, 38.61) = 26.28, p<.001; joint independence, F(1.6,42.6) = 17.20, p<.001; FMA, F(2, 52) = 27.55, p<.001; WMFT, F(2, 52) =14.05, p<.001]. There were no differential effects of external focus or internal focus on the retention of motor skills after four weeks of arm training, suggesting that individuals with moderate-to-severe arm impairment may not experience the advantages of an external focus found in healthy individuals. The current theoretical model (Constrained Action Hypothesis) may need to be expanded and modified to account for individuals with moderate-to-severe motor impairments after stroke. Attentional focus is most likely not an active ingredient for retention of trained motor skills in individuals with moderate-to-severe arm impairment after stroke, whereas, dosage and intensity of practice appear to be pivotal.