Pang M1, Yang L1,2,3, Ouyang H1,4, Lam F1,5, Huang M1, Jehu D6
1Hong Kong Polytechnic University (PolyU)., Department of Rehabilitation Sciences, Kowloon, Hong Kong, 2The 2nd Affiliated Hospital of Kunming Medical University, Department of Rehabilitation Medicine, Kunming, China, 3Sichuan University-Hong Kong Polytechnic University, Institute of Disaster Management and Reconstruction, Chengdu, China, 4Guangdong Provincial Work Injury Rehabilitation Hospital, Department of Physical Therapy, Guangzhou, China, 5The Chinese University of Hong Kong, Department of Medicine and Therapeutics, Shatin, Hong Kong, 6University of British Columbia, Faculty of Medicine, Physical Therapy Department, Vancouver, Canada
Background: The ability to perform a mobility and cognitive task simultaneously (dual-tasking) is essential in functional ambulation and is often impaired after stroke. Poor dual-task mobility has also been associated with falls following stroke. It is thought that dual-task exercise interventions may improve the capacity to process information, thereby enhancing dual-task performance. The preliminary findings from previous research with small sample sizes have demonstrated that dual-task exercise training may induce gain in dual-task mobility function in individuals with stroke. However, no study has examined the effect of dual-task exercise training on falls post-stroke.
Purpose: This randomized controlled study aimed to examine the effects of dual-task exercise on cognitive-motor interference during ambulation, balance self-efficacy, participation in daily activities, quality of life and falls in people with chronic stroke.
Methods: Eighty-four people with chronic stroke (24 women; age: 61.2±6.4 years; time since stroke onset: 75.3±64.9 months) with independent mobility function and intact cognition were randomly allocated to the dual-task balance/mobility training group, single-task balance/mobility group, or upper-limb exercise (control) group. Each group underwent their respective exercise training for three 1-hour sessions per week for 8 weeks. Outcome measurements were conducted at baseline, within one week after, and 8 weeks after training by a blinded researcher. The dual-task interference effect (primary outcome) was measured for the time taken to complete the three mobility tasks (forward walking, Timed-up-and-go, and obstacle-crossing), and the correct response rate during serial-3-subtractions and verbal fluency task. The Activities-specific Balance Confidence Scale, Frenchay Activities Index, and Stroke-specific Quality of Life Scale were also measured (secondary outcomes). In addition, fall incidence was recorded for a 6-month period post-training.
Results: The results revealed an overall group × time interaction effect in walking time of three dual-task conditions (forward walking with verbal fluency, forward walking with serial-3-subtractions, and Timed-up-and-go with verbal fluency)(p 0.05). Post-hoc analysis showed that only the dual-task group demonstrated reduced dual-task walking time post-training [forward walking with verbal fluency (9.5%, p=0.014), forward walking with serial-3-subtractions (9.6%, p=0.035), and the timed-up-and-go with verbal fluency (16.8%, p=0.001)]. These improvements were largely preserved at the 8-week follow-up. On the other hand, the dual-task cognitive performance showed no significant changes across groups (p>0.05). The dual-task program reduced the risk of falls and injurious falls by 25.0% (95%CI: 3.1-46.9%, p=0.037) and 22.2% (95%CI: 4.0-38.4%, p=0.023), respectively during the 6-month follow-up period compared with controls. No significant effect on other secondary outcomes was found (p>0.05).
Conclusion(s): The dual-task program improves dual-task mobility and reduces falls and related injuries in ambulatory individuals with chronic stroke who have intact cognitive function.
Implications: It is necessary to train dual-tasking to improve dual-tasking. This study can be used to inform the design of fall-prevention interventions in community-dwelling individuals with chronic stroke. The dual-task program did not involve expensive equipment. The exercises involved were also simple enough so that family members/caregivers could carry out the exercise sessions as a home program after proper training by physical therapists. This program has the potential for widespread, economical, and sustainable applications in community- and home-based settings.
Keywords: Stroke, mobility, balance
Funding acknowledgements: General Research Fund; 151594/16M)
The Institute for Disaster Management and Reconstruction, Sichuan University - Hong Kong Polytechnic University.
Purpose: This randomized controlled study aimed to examine the effects of dual-task exercise on cognitive-motor interference during ambulation, balance self-efficacy, participation in daily activities, quality of life and falls in people with chronic stroke.
Methods: Eighty-four people with chronic stroke (24 women; age: 61.2±6.4 years; time since stroke onset: 75.3±64.9 months) with independent mobility function and intact cognition were randomly allocated to the dual-task balance/mobility training group, single-task balance/mobility group, or upper-limb exercise (control) group. Each group underwent their respective exercise training for three 1-hour sessions per week for 8 weeks. Outcome measurements were conducted at baseline, within one week after, and 8 weeks after training by a blinded researcher. The dual-task interference effect (primary outcome) was measured for the time taken to complete the three mobility tasks (forward walking, Timed-up-and-go, and obstacle-crossing), and the correct response rate during serial-3-subtractions and verbal fluency task. The Activities-specific Balance Confidence Scale, Frenchay Activities Index, and Stroke-specific Quality of Life Scale were also measured (secondary outcomes). In addition, fall incidence was recorded for a 6-month period post-training.
Results: The results revealed an overall group × time interaction effect in walking time of three dual-task conditions (forward walking with verbal fluency, forward walking with serial-3-subtractions, and Timed-up-and-go with verbal fluency)(p 0.05). Post-hoc analysis showed that only the dual-task group demonstrated reduced dual-task walking time post-training [forward walking with verbal fluency (9.5%, p=0.014), forward walking with serial-3-subtractions (9.6%, p=0.035), and the timed-up-and-go with verbal fluency (16.8%, p=0.001)]. These improvements were largely preserved at the 8-week follow-up. On the other hand, the dual-task cognitive performance showed no significant changes across groups (p>0.05). The dual-task program reduced the risk of falls and injurious falls by 25.0% (95%CI: 3.1-46.9%, p=0.037) and 22.2% (95%CI: 4.0-38.4%, p=0.023), respectively during the 6-month follow-up period compared with controls. No significant effect on other secondary outcomes was found (p>0.05).
Conclusion(s): The dual-task program improves dual-task mobility and reduces falls and related injuries in ambulatory individuals with chronic stroke who have intact cognitive function.
Implications: It is necessary to train dual-tasking to improve dual-tasking. This study can be used to inform the design of fall-prevention interventions in community-dwelling individuals with chronic stroke. The dual-task program did not involve expensive equipment. The exercises involved were also simple enough so that family members/caregivers could carry out the exercise sessions as a home program after proper training by physical therapists. This program has the potential for widespread, economical, and sustainable applications in community- and home-based settings.
Keywords: Stroke, mobility, balance
Funding acknowledgements: General Research Fund; 151594/16M)
The Institute for Disaster Management and Reconstruction, Sichuan University - Hong Kong Polytechnic University.
Topic: Neurology; Neurology
Ethics approval required: Yes
Institution: Hong Kong Polytechnic University
Ethics committee: The Human Ethics Research Subcommittee
Ethics number: HSEARS20140714003
All authors, affiliations and abstracts have been published as submitted.
