Rehabilitation for Chronic Stroke: Better Balance Through Yoga?
Abstract & Commentary
By Nancy J. Selfridge, MD
Associate Professor, Integrated Medical Education, Ross University School of Medicine, Commonwealth of Dominica, West Indies
Dr. Selfridge reports no financial relationships relevant to this field of study.
Synopsis: An 8-week yoga training program improved balance performance measures and reduced fear of falling in adult patients with a history of stroke.
Source: Schmid AA, et al. Poststroke balance improves with yoga: A pilot study. Stroke 2012;43:2402-2407.
Falls are one of the most common complications after stroke. In a multicenter study, Langhorne et al reported a post-stroke incidence of such falls in 25% of 311 patients. Of the falls, 5% were associated with significant injury to the patient.1 Persistent balance, strength, and sensory deficits are the underlying factors associated with increased risk of falling after a stroke. Thus, current clinical practice guidelines recommend balance training for stroke victims who demonstrate balance impairment.2 With specific balance training recommendations and protocols not being currently available, the authors of this pilot study set out to determine whether yoga training would improve balance and stroke recovery based on case studies and qualitative research, which suggest a benefit for stroke patients and for elderly in general.
A total of 47 patients with chronic stroke of greater than 6 months’ duration were selected from 222 potentially eligible patients who were identified by chart review, recruited from stroke support groups, or recruited from previously completed stroke research studies in the Indianapolis area. Selectees were randomly assigned to an intervention group (n = 37) or a wait-list control group (n = 10). The intervention consisted of an hour-long, adapted, yoga-based protocol in a group setting twice weekly for 8 weeks. Postures were chosen and taught by a registered yoga therapist with input from the research team based on previous evidence supporting improved balance through a focus on increased hip and ankle flexibility as well as strength. Class members used bands, bolsters, and other assistive devices to help them attain and maintain the yoga postures. Measures were performed at baseline and 8 weeks after completion of the yoga program. Stroke-related disability was rated using a modified Rankin Scale, which is a validated instrument for determining the degree of disability and dependence after stroke. According to this scale, functional independence is defined as a score of 0-2 and dependence as a score of 3-5. The Berg Balance Scale, a validated physical performance assessment, was used to assess static and dynamic balance. Scores ≤ 46 identify patients who are at risk for falls after stroke. Patients reported balance self-efficacy using the Activities-specific Balance Confidence Scale, another validated and reliable assessment tool for stroke victims, ranging from “no confidence” (0%) to “completely confident” (100%). Fear of falling was measured with a simple yes/no question. Quality-of-life data were collected using the Stroke-Specific Quality of Life scale, previously demonstrating validity in stroke research. In the intervention group, 29 patients completed all 16 yoga sessions and post-assessments. Three patients were lost to follow up, four completed fewer than five sessions due to scheduling or transportation problems, and one patient was hospitalized for reasons unrelated to the intervention. The authors noted no statistically significant differences between the control and intervention groups in baseline or 8-week measures. However, they did note improvement in all measures in the intervention group from baseline to 8-week follow-up and these changes were significant. In contrast, the control group demonstrated no significant improvement in measures from baseline and follow-up. Balance improved significantly in the yoga group (P < 0.001) coupled with fewer yoga participants answering “yes” to the fear of falling question (P < 0.001) and a greater number were identified as “independent” on the modified Rankin Scale (P < 0.001). Though less impressive, there also was significant improvement in quality of life (P < 0.037) and balance self-efficacy (P < 0.035). Interestingly, the patients whose baseline balance scores were ≤ 46 improved to an even greater degree, with a mean increase of 8 points.
Yoga again emerges as a potential therapeutic intervention, this time for patients with a history of stroke and sequelae. Improvements in the intervention group were not only statistically significant but also clinically meaningful. Berg Balance Scale scores of ≤ 45 indicate a higher risk of falling, and elderly, community-dwelling adults without stroke generally have scores > 50. So, for many of the yoga participants in this study, balance improved enough to mitigate their increased risk of falling. High adherence rates and no adverse effects suggest feasibility and patient acceptance. However, the size of this pilot study limited its power to detect differences between the control and intervention groups, and without an adequate control group, it could be argued that improvements represented regression to the mean. The authors initially divided the intervention group into two cohorts: both received the 8-week yoga intervention, but one group also received a home audio device and preloaded 20-minute recording and were instructed to listen to and track their use at least three times weekly. Since there were no differences in the outcome measures at 8 weeks between these two intervention groups, the authors decided to collapse the data into one intervention group for analysis. It would be interesting to see if differences between these intervention groups and the control group emerged with a larger sample size or a longer intervention. Assessments were completed by a research assistant who also assisted with the yoga sessions; therefore, the study was not blinded to the primary outcome assessment, a significant methodological flaw. The study sample included a low enrollment of women, and thus was not representative of the stroke population in general. An active control arm to monitor for group effect would help discern what elements of this yoga intervention are most effective. Long-term maintenance of improvement would be important to document in future studies. Despite the great promise in this pilot study, future research correcting for these shortcomings is necessary before group yoga can be added to clinical practice guidelines for stroke rehabilitation.
1. Langhorne P, et al. Medical complications after stroke: A multicenter study. Stroke 2000;31:1223-1229.
2. Duncan PW, et al. Management of adult stroke rehabilitation care: A clinical practice guideline. Stroke 2005;36:100-143.