Stacey E. Aaron

The Effects of POWER Training in Young and Older Adults after Stroke.

Background. Approximately 35,000 strokes occur annually in adults below the age of 40, and there is disappointingly little data describing their responses to rehabilitation. The purpose of this analysis was to determine the effects of Poststroke Optimization of Walking using Explosive Resistance (POWER) training in young (<40 years) and older (>60 years) adults and to describe relationships between training-induced improvements in muscular and locomotor function. Methods. Data was analyzed from 16 individuals with chronic stroke who participated in 24 sessions of POWER training. Outcomes included muscle power generation, self-selected walking speed (SSWS), 6-minute walk test, Fugl-Meyer motor assessment, Berg Balance Scale, and Dynamic Gait Index. Results. There were no significant differences between groups at baseline. Within-group comparisons revealed significant improvements in paretic and nonparetic knee extensor muscle power generation in both groups. Additionally, young participants significantly improved SSWS. Improvements in SSWS were more strongly associated with improvements in power generation on both sides in young versus older participants. Conclusions. Younger adults after stroke seem to preferentially benefit from POWER training, particularly when increasing gait speed is a rehabilitation goal. Future research should aim to further understand age-related differences in response to training to provide optimal treatments for all individuals following stroke.

Lower Odds of Poststroke Symptoms of Depression When Physical Activity Guidelines Met: National Health and Nutrition Examination Survey 2011–2012

BACKGROUND One-third of individuals with stroke report symptoms of depression, which has a negative impact on recovery. Physical activity (PA) is a potentially effective therapy. Our objective was to examine the associations of subjectively assessed PA levels and symptoms of depression in a nationally representative stroke sample. METHODS We conducted a cross-sectional study of 175 adults in the National Health and Nutrition Examination Survey 2011-2012 cycle. Moderate, vigorous, and combination equivalent PA metabolic equivalent (MET)-minutes per week averages were derived from the Global Physical Activity Questionnaire, and .the 2008 Physical Activity Guidelines/American College of Sports Medicine recommendations of ≥500 MET-minutes per week of moderate, vigorous, or combination equivalent PA were used as cut points. Depression symptoms were measured using the Patient Health Questionnaire-9. RESULTS Meeting moderate PA guidelines resulted in 74% lower odds of having depression symptoms (P < .0001) and 89% lower odds of major symptoms of depression (P = .0003). Meeting vigorous guidelines showed a 91% lower odds of having mild symptoms of depression (P = .04). Participating in some moderate, vigorous, or combination equivalent PA revealed the odds of depression symptoms 13 times greater compared with meeting guidelines (P = .005); odds of mild symptoms of depression were 9 times greater (P = .01); and odds of major symptoms of depression were 15 times greater (P = .006). CONCLUSIONS There is a lower risk of developing mild symptoms of depression when vigorous guidelines for PA are met and developing major symptoms of depression when moderate guidelines met. Participating in some PA is not enough to reduce the risk of depression symptoms.

Combining therapeutic approaches: rTMS and aerobic exercise in post-stroke depression: a case series

Abstract Objective and importance Residual effects of stroke include well-documented functional limitations and high prevalence of depression. Repetitive transcranial magnetic stimulation (rTMS) and aerobic exercise (AEx) are established techniques that improve depressive symptoms, but a combination of the two has yet to be reported. The purpose of this case series is to examine the safety, feasibility, and impact of combined rTMS and AEx on post-stroke depression and functional mobility. Clinical presentation Three participants with a history of stroke and at least mild depressive symptoms (Patient Health Questionare-9 ≥5). Intervention Both rTMS and AEx were completed 3 times/week for 8-weeks. rTMS was applied to the left dorsolateral prefrontal cortex, 5000 pulses/session at 10 Hz, at an intensity of 120% of resting motor threshold. AEx consisted of 40 min of treadmill walking at 50–70% of heart rate reserve. Results Depressive symptoms improved in all three participants, with all demonstrating response (≥50% improvement in symptoms) and likely remission. All participants improved their Six Minute Walk Test distance and Participants 1 and 2 also improved Berg Balance Scale scores. Participants 1 and 3 improved overground walking speeds. No serious adverse events occurred with the application of rTMS or AEx and the participants’ subjective reports indicated positive responses. Adherence rate for both rTMS and AEx was 98%. Conclusion Combined treatment of rTMS and AEx appears safe, feasible, and tolerable in individuals with a history of stroke and at least mild depressive symptoms. All participants had good compliance and demonstrated improvements in both depressive symptoms and walking capacity.

Physical Activity and the Risk of Depression in Community-Dwelling Korean Adults With a History of Stroke.

Background Physical activity (PA) is believed to improve mental health, including depression. However, whether recommended PA levels have a similar impact in individuals with poststroke depression is unclear. Objective The aim of this study was to apply a quasi‐experimental propensity score (PS) matching control for covariate differences and compare the effects of PA on reducing depression risk among people with stroke. Design A cross‐sectional design was used for this study. Methods Health‐related information for community‐dwelling adults (N=4,555) who reported having had a stroke was extracted from the 2013 Korean Community Health Survey data set. The survey participants were asked a series of questions about depression, recommended PA levels (moderate and vigorous intensity), and chronic conditions. A multivariable regression model, inverse probability weighting adjustment, and Greedy algorithms with 1:1 matching and covariate adjustment were used to estimate the effects of PA on risk of depression. The dependent variable was diagnosis of depression, and the primary independent variable was PA. Baseline covariates were 10 demographic and 9 chronic condition variables. Results Without PS methods, there were significant differences in baseline covariates (16 out of 19) between people who performed PA and those who did not perform PA. After applying 1:1 matching, the number of patients in each group comparing the effect of PA numbered 1,970, and 13 covariates did not differ significantly between the 2 groups. Physical activity reduced the risk of poststroke depression by 36.1% to 42.4% (odds ratio=0.639‐0.376) across the 3 methods. Limitations Unaccounted‐for covariates, including stroke severity, predepression status, and history of depression treatments, may have biased the results. Conclusions The findings suggest that recommended PA levels have protective relationships with the risk of poststroke depression.

Feasibility of single session high-intensity interval training utilizing speed and active recovery to push beyond standard practice post-stroke

ABSTRACT Background: Improvement in overground walking speed reduces dependency and is a central focus in post-stroke rehabilitation. Previous studies have shown that high-intensity interval training (HIT) can significantly improve functional and health-related outcomes in neurologically health individuals more so than traditional approaches. Emerging evidence suggests the same may be true post-stroke. Objective: The purpose of this study was to assess the feasibility of a single session, novel HIT design. Methods: Participants walked on a treadmill, alternating between one minute at high-intensity and one minute at low-intensity for 20 minutes, adjusting the speed of the treadmill to dictate intensity. Treadmill speeds were determined from overground self-selected walking speed (SSWS). Results: No adverse events occurred during the training sessions. High-intensity treadmill speeds were significantly faster than treadmill SSWS (standard practice; +227%; p < 0.0001) and overground SSWS (+142%; p = 0.003). 15 of the 21 subjects were able to walk on the treadmill at 150% of overground SSWS; with the remaining individuals (n = 6) walking at 123% of overground SSWS. Average peak heart rate during HIT was 90% of age-predicted max. Conclusions: These results demonstrate the feasibility of this single session HIT design and suggest that individuals following stroke are capable of prolonged training at speeds significantly faster than standard practice. Additionally, this training intensity elicited heart rate responses in the upper range of vigorous exercise. Future studies are needed to investigate a progressive HIT intervention applying this design and its effects on functional outcomes as well as cardiovascular fitness.

POWER training in chronic stroke individuals: differences between responders and nonresponders

Abstract Background: Lower extremity muscle weakness is a primary contributor to post-stroke dysfunction. Resistance training is an effective treatment for hemiparetic weakness and improves walking performance. Post-stroke subject characteristics that do or do not improve walking speed following resistance training are unknown. Objective: The purpose of this paper was to describe baseline characteristics, as well as responses to training, associated with achieving a minimal clinically important difference (MCID) in walking speed (≥0.16 m/s) following Post-stroke Optimization of Walking Using Explosive Resistance (POWER) training. Methods: Seventeen participants completed 24 sessions of POWER training, which included intensive progressive leg presses, jump training, calf raises, sit-to-stands, step-ups, and over ground fast walking. Outcomes included SSWS, FCWS, DGI, FMA-LE, 6-MWT, paretic knee power, non-paretic knee power, and paretic step ratio. Results: Specific to those who reached MCID in SSWS (e.g. “responders”), significant improvements in SSWS, FCWS, 6-MWT, paretic knee power, and non-paretic knee power was realized. Paretic knee power and non-paretic knee power significantly improved in those who did not achieve MCID for gait speed (e.g. “non-responders”). Conclusion: The potential for POWER training to enhance general locomotor function was confirmed. Baseline paretic knee strength/power may be an important factor in how an individual responds to this style of training. The lack of change within the non-responders emphasizes the contribution of factors other than lower extremity muscle power improvement to locomotor dysfunction.

FES-Assisted Cycling Improves Aerobic Capacity and Locomotor Function Post-CVA

PURPOSE After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional Electrical Stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. METHODS Eleven individuals with chronic (> 6 months) post-CVA hemiparesis completed an 8-week (3x/wk; 24 sessions) progressive FES-assisted cycling intervention. VO2peak, self-selected and fastest comfortable walking speeds, gait and pedaling symmetry, 6-minute walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and post-training. RESULTS FES-assisted cycling significantly improved VO2peak (12%, p=0.006), self-selected walking speed (SSWS, 0.05±0.1 m/s, p=0.04), Activities-specific Balance Confidence scale score (12.75±17.4, p=0.04), Berg Balance Scale score (3.91±4.2, p=0.016), Dynamic Gait Index score (1.64±1.4, p=0.016), and Stroke Impact Scale participation/role domain score (12.74±16.7, p=0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (PPR) significantly improved (10.09±9.0%, p=0.016). Although step length symmetry (PSR) did improve, these changes were not statistically significant (-0.05±0.1%, p=0.09). Exploratory correlations showed moderate association between change in SSWS and 6MWT (r=0.74), and moderate/strong negative association between change in PPR and PSR. CONCLUSION These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals following CVA. Interestingly, the correlation between PSR and PPR suggests that improvements in pedaling symmetry may translate to a more symmetric gait pattern.PURPOSE After a cerebrovascular accident (CVA) aerobic deconditioning contributes to diminished physical function. Functional electrical stimulation (FES)-assisted cycling is a promising exercise paradigm designed to target both aerobic capacity and locomotor function. This pilot study aimed to evaluate the effects of an FES-assisted cycling intervention on aerobic capacity and locomotor function in individuals post-CVA. METHODS Eleven individuals with chronic (>6 months) post-CVA hemiparesis completed an 8-wk (three times per week; 24 sessions) progressive FES-assisted cycling intervention. V˙O2peak, self-selected, and fastest comfortable walking speeds, gait, and pedaling symmetry, 6-min walk test (6MWT), balance, dynamic gait movements, and health status were measured at baseline and posttraining. RESULTS Functional electrical stimulation-assisted cycling significantly improved V˙O2peak (12%, P = 0.006), self-selected walking speed (SSWS, 0.05 ± 0.1 m·s, P = 0.04), Activities-specific Balance Confidence scale score (12.75 ± 17.4, P = 0.04), Berg Balance Scale score (3.91 ± 4.2, P = 0.016), Dynamic Gait Index score (1.64 ± 1.4, P = 0.016), and Stroke Impact Scale participation/role domain score (12.74 ± 16.7, P = 0.027). Additionally, pedal symmetry, represented by the paretic limb contribution to pedaling (paretic pedaling ratio [PPR]) significantly improved (10.09% ± 9.0%, P = 0.016). Although step length symmetry (paretic step ratio [PSR]) did improve, these changes were not statistically significant (-0.05% ± 0.1%, P = 0.09). Exploratory correlations showed moderate association between change in SSWS and 6-min walk test (r = 0.74), and moderate/strong negative association between change in PPR and PSR. CONCLUSIONS These results support FES-assisted cycling as a means to improve both aerobic capacity and locomotor function. Improvements in SSWS, balance, dynamic walking movements, and participation in familial and societal roles are important targets for rehabilitation of individuals after CVA. Interestingly, the correlation between PSR and PPR suggests that improvements in pedaling symmetry may translate to a more symmetric gait pattern.

Dynamic gait index post-stroke: What is the item hierarchy and what does it tell the clinician? A Rasch analysis

Aims: The purpose of this study was to use the Rasch measurement model to determine (1) the dynamic gait index (DGI) item-level psychometrics, (2) if the item-difficulty hierarchical order is consistent with a clinically logical progression from easiest to hardest, and (3) if the range of tasks is sufficient to measure the functional ability levels of the sample. Methods: Data were retrieved retrospectively from study records, which included initial DGI scores and subject demographics collected at multiple university laboratories. Individuals were eligible Stacey E. Aaron1, Ickpyo Hong1, Mark G. Bowden2, Chris M. Gregory2, Aaron E. Embry3, Craig A. Velozo4 Affiliations: 1PhD Candidate, Department of Health Sciences & Research, Medical University of South Carolina, Charleston, South Carolina, United States; 2Associate Professor, Department of Health Sciences & Research, Medical University of South Carolina, Charleston, South Carolina, United States; Division of Physical Therapy, Medical University of South Carolina, Charleston, South Carolina, United States; Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States; 3Research Associate, Department of Health Sciences & Research, Medical University of South Carolina, Charleston, South Carolina, United States; Division of Physical Therapy, Medical University of South Carolina, Charleston, South Carolina, United States; Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States; 4Occupational Therapy Division Director and Professor, Division of Occupational Therapy, Medical University of South Carolina, Charleston, South Carolina, United States. Corresponding Author: Stacey Elizabeth Aaron, MS, 77 President St, MSC 700, Charleston, South Carolina, United States, 29425; E-mail: aarons@musc.edu Received: 04 August 2016 Accepted: 29 August 2016 Published: 26 September 2016 to participate if 18+ years of age, >6 months post-stroke, residual paresis in lower extremity, and ability to walk with/without assistive device (n=117). Psychometrics of the DGI were tested with confirmatory factor analysis (CFA) and Rasch measurement modeling. Results: DGI demonstrated acceptable psychometric properties: unidimensionality (CFA: χ2/df =2.12, CFI=0.98, TLI=0.97, RMSEA=0.09), no misfit items to the Rasch model, local independence (all item residual correlations <0.2), and a good internal reliability (Cronbach alpha of 0.86). Item-level analysis revealed a clear itemdifficulty hierarchical order that is consistent with clinical observation and expectations. While the instrument separates the sample into three significant strata, there was mismatch between the average of person ability distribution (0.86 logit) and the average of item difficulties (0.00 logit). Conclusion: The DGI demonstrated good item-level psychometric properties and an expected item-difficulty hierarchical order. Order of administration and adding more challenging items may improve precision and person-item matching to better differentiate between individuals with higher ability levels.