Master of Science (MSc)
Faculty of Science
Dr. Quincy J. Almeida
Parkinson’s disease impairs control of well-learned movements, and therefore, individuals with Parkinson’s disease are forced to walk with greater conscious control. This causes difficulties while walking and completing a secondary task simultaneously (dual tasking), in that distractions from conscious control of walking increase the risk of falls and injury. Although, attention-based exercise may be a potential avenue to decrease the demands associated with walking in Parkinson’s disease. For example, an external focus of attention (on manipulated objects) has been found to recruit the networks that are important for walking with little conscious control (automatic control networks). In contrast, an internal focus (on limb movements) has been found to recruit conscious control networks. Unexpectedly, an external focus of attention (compared to an internal) has been found to improve postural stability in Parkinson’s disease (compared to internal) despite that this attentional focus recruits damaged automatic control circuits. Therefore, promoting an external focus during goal-based exercise may improve upon automatic control functioning, and therefore, improve the ability to dual task and reduce the severity of symptoms.
A parallel group, single blind, randomized controlled trial was conducted. Thirty-nine participants with Parkinson’s disease were randomized to one of two exercise groups: 1) External focus of attention (focus on movement of coloured labels attached to limbs, n=19) or 2) Internal focus of attention (focus on movement of limbs, n=20). Both exercise groups completed 33 one-hour goal-based exercise sessions over 11 weeks. Eleven participants were assigned to a non-exercise control group. Walking ability (single and dual tasking) and symptom severity (Unified Parkinson’s disease Rating Scale motor subsection [UPDRS-III] ON and OFF dopamine medications) were assessed before and after (pre/post) the completion of the program, and 8 weeks after exercise cessation (washout). As a result of the intervention, walking ability while completing a secondary task became significantly worse in the Internal focus of attention exercise group, while dual tasking ability did not change in the external group. Symptom severity significantly improved in only the External group from pre to post. From pre to washout, dual task walking ability and motor symptom severity improved in both exercise groups. However, the Internal group had increased errors on the dual task, whereas the External group did not, indicating that improvements were only demonstrated in the External group.
Thus, External focus of attention exercise may provide benefits that establish a foundation for improvements to dual task walking ability in Parkinson’s disease, whereas adopting an Internal focus of attention during goal-based exercise appeared to increase reliance on conscious control of movement, hindering dual tasking ability. Additionally, after the exercise program, greater improvements to symptom severity were found after externally focused exercise compared to internally focused. Together, these findings indicate that focusing externally on the manipulation of coloured labels while exercising provides greater rehabilitation effectiveness in Parkinson’s disease compared to focusing internally on limb movements.
Beck, Eric N., "The effects of external focus of attention exercise rehabilitation on dual task walking in Parkinson's disease" (2016). Theses and Dissertations (Comprehensive). 1858.
Available for download on Saturday, September 01, 2018
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