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Patients with Parkinson disease (PD) may have decreased physical activity due to motor deficits. We recently validated the reliability of step activity monitors (SAMs) to accurately count steps in PD, and we wished to use them to evaluate the impact of disease severity on home activity levels in PD. Twenty-six subjects with PD (Hoehn and Yahr disease stage 2-4) were recruited to participate in a study of activity levels over 48 hours. Ability to achieve 95% device accuracy was an entry requirement. A Unified Parkinson Disease Rating Scale (UPDRS) evaluation was performed on all subjects, subjects were monitored for 48 hours, and total number of steps per day and maximum steps taken per hour were calculated. Out of 26 subjects, 25 met entry requirements. We calculated the number of steps taken per day, as well as maximal activity levels, and correlated these with UPDRS total score, the activity of daily living subscale, and the UPDRS motor function subscale off and on medication (all p < 0.01). Transition from Hoehn and Yahr stage 2 to stage 3 was associated with a decline in functional mobility (p < 0.005). A microprocessor-linked SAM accurately counted steps in subjects with PD. The number of steps taken correlated highly with disease severity. SAMs may be useful outcome measures in PD. [ABSTRACT FROM AUTHOR]

This study investigated the effects of an adaptive physical activity (APA) program on mobility function and quality of life (QOL) in chronic stroke patients. Twenty subjects with chronic hemiparesis completed a 2-month, combined group, class-home exercise regimen that emphasized mobility training. APA improved Berg Balance Scale scores (35 +/- 2 vs 45 +/- 2, p = 0.001), 6-minute walk distances (114 +/- 15 vs 142 +/- 7 m, p < 0.001), and Short Physical Performance Battery scores (3.2 +/- 0.4 vs 5.2 +/- 0.6, p < 0.001). Barthel Index scores increased (75 +/- 4 vs 84 +/- 4, p < 0.001), but Lawton scores were unchanged. Geriatric Depression Scale (p < 0.01) and Stroke Impact Scale (SIS), Mobility, Participation, and Recovery improved with APA (p < 0.03). APA has the potential to improve gait, balance, and basic but not instrumental activities of daily living profiles in individuals with chronic stroke. Improved depression and SIS scores suggest APA improves stroke-specific outcomes related to QOL. [ABSTRACT FROM AUTHOR]

The effects of task-repetitive locomotor training on stroke patients' spatial and temporal gait parameters during unassisted walking are not well understood. This study determined the effects of treadmill aerobic exercise (T-EX) on spatial and temporal gait parameters that underlie changes in overground walking function. Thirty-nine subjects with hemiparetic stroke underwent T-EX three times weekly for 6 months. We measured the subjects pre- and posttraining on 30-foot timed walks and 6-minute distance walks with usual assistive devices and on an 8 m instrumented walkway without assistive devices. T-EX improved 30-foot walks by 17% and 6-minute walks by 23%. Unassisted walking velocity increased 22%, stride length increased 13%, and cadence increased 7%. Paretic and nonparetic step lengths increased significantly, and respective step times decreased significantly. Interlimb symmetry did not change. This study presents preliminary evidence that changes in spatial and temporal gait parameters contribute to the increased velocity of subjects with stroke after T-EX. [ABSTRACT FROM AUTHOR]

Patients with stroke have elevated hemiparetic gait costs secondary to low activity levels and are often severely deconditioned. Decrements in peak aerobic capacity affect functional ability and cardiovascular-metabolic health and may be partially mediated by molecular changes in hemiparetic skeletal muscle. Conventional rehabilitation is time delimited in the subacute stroke phase and does not provide adequate aerobic intensity to reverse the profound detriments to fitness and function that result from stroke. Hence, we have studied progressive full body weight-support treadmill (TM) training as an adjunct therapy in the chronic stroke phase. Task-oriented TM training has produced measurable changes in fitness, function, and indices of cardiovascular-metabolic health after stroke, but the precise mechanisms for these changes remain under investigation. Further, the optimal dose of this therapy has yet to be identified for individuals with stroke and may vary as a function of deficit severity and outcome goals. This article summarizes the functional and metabolic decline caused by inactivity after stroke and provides current evidence that supports the use of TM training during the chronic stroke phase, with protocols and inclusion/exclusion criteria described. Our research findings are discussed in relation to associated research. [ABSTRACT FROM AUTHOR]

Hemiparetic stroke leads to major skeletal muscle abnormalities, as illustrated by paretic leg atrophy, weakness, and spasticity. Furthermore, the hemiparetic limb muscle shifts to a fast-twitch muscle fiber phenotype with anaerobic metabolism. This study investigated whether skeletal muscle genes were altered in chronic hemiparetic stroke. The nonparetic leg muscle served as an internal control. We used Affymetrix microarray analysis to survey gene expression differences between paretic and nonparetic vastus lateralis muscle punch biopsies from 10 subjects with chronic hemiparetic stroke. Stroke latency was greater than 6 months. We found that 116 genes were significantly altered between the paretic and non paretic vastus lateralis muscles. These gene differences were consistent with reported differences after stroke in areas such as injury and inflammation markers, the myosin heavy chain profile, and high prevalence of impaired glucose tolerance and type 2 diabetes. Furthermore, while many other families of genes were altered, the gene families with the most genes altered included inflammation, cell cycle regulation, signal transduction, metabolism, and muscle contractile protein genes. This study is an early step toward identification of specific gene regulatory pathways that might lead to these differences, propagate disability, and increase vascular disease risk. [ABSTRACT FROM AUTHOR]

Stroke is the leading cause of disability in the United States. New evidence reveals significant structural and metabolic changes in skeletal muscle after stroke. Muscle alterations include gross atrophy and shift to fast myosin heavy chain in the hemiparetic (contralateral) leg muscle; both are related to gait deficit severity. The underlying molecular mechanisms of this atrophy and muscle phenotype shift are not known. Inflammatory markers are also present in contralateral leg muscle after stroke. Individuals with stroke have a high prevalence of insulin resistance and diabetes. Skeletal muscle is a major site for insulin-glucose metabolism. Increasing evidence suggests that inflammatory pathway activation and oxidative injury could lead to wasting, altered function, and impaired insulin action in skeletal muscle. The health benefits of exercise in disabled populations have now been recognized. Aerobic exercise improves fitness, strength, and ambulatory performance in subjects with chronic stroke. Therapeutic exercise may modify or reverse skeletal muscle abnormalities. [ABSTRACT FROM AUTHOR]

Purpose: This systematic umbrella review examines and updates the evidence on the relationship between physical activity (PA) and blood pressure (BP) presented in the 2008 Physical Activity Guidelines Advisory Committee Scientific Report., Methods: We performed a systematic review to identify systematic reviews and meta-analyses involving adults with normal BP, prehypertension, and hypertension published from 2006 to February 2018., Results: In total, 17 meta-analyses and one systematic review with 594,129 adults ≥18 yr qualified. Strong evidence demonstrates: 1) an inverse dose-response relationship between PA and incident hypertension among adults with normal BP; 2) PA reduces the risk of cardiovascular disease (CVD) progression among adults with hypertension; 3) PA reduces BP among adults with normal BP, prehypertension, and hypertension; and 4) the magnitude of the BP response to PA varies by resting BP, with greater benefits among adults with prehypertension than normal BP. Moderate evidence indicates the relationship between resting BP and the magnitude of benefit does not vary by PA type among adults with normal BP, prehypertension, and hypertension. Limited evidence suggests the magnitude of the BP response to PA varies by resting BP among adults with hypertension. Insufficient evidence is available to determine if factors such as sex, age, race/ethnicity, socioeconomic status, and weight status or the frequency, intensity, time, and duration of PA influence the associations between PA and BP., Conclusions: Future research is needed that adheres to standard BP measurement protocols and classification schemes to better understand the influence of PA on the risk of comorbid conditions, health-related quality of life, and CVD progression and mortality; the interactive effects between PA and antihypertensive medication use; and the immediate BP-lowering benefits of PA.

Objective: (1) To compare paretic (P) vs nonparetic (NP) skeletal muscle brain-derived neurotrophic factor (BDNF) and the effects of resistive training (RT) on systemic and skeletal muscle BDNF mRNA expression in stroke; and (2) to compare the DNA methylation profile for BDNF and BDNFAS (BDNF antisense RNA) between P and NP muscle and the effects of aerobic exercise training (AEX) on DNA methylation in stroke., Methods: In this longitudinal investigation, participants (50-76 years) with chronic stroke underwent a fasting blood draw, a 12-week (3×/week) RT intervention (n = 16), and repeated bilateral vastus lateralis muscle tissue biopsies (n = 10) with BDNF expression determined by RT-PCR. Five stroke survivors completed 6 months of AEX (3×/week) and had bilateral muscle biopsies. DNA methylation status in gene BDNF and BDNFAS was assessed by Illumina 450k methylation array., Results: P muscle had ∼45% lower BDNF mRNA expression than NP muscle (6.79 ± 1.30 vs 10.52 ± 2.06 arbitrary units [AU], p < 0.05), and P muscle exhibited differential methylation status in the DNA sequences of BDNF (3 CpG [5'-C-phosphate-G-3'] sites, p = 0.016-0.044) and BDNFAS (1 CpG site, p = 0.016) compared to NP. Plasma BDNF and muscle BDNF messenger RNA (mRNA) expression did not significantly change after RT. BDNFAS DNA methylation increased after AEX in P relative to NP muscle ( p = 0.017)., Conclusions: This is the first evidence that stroke hemiparesis reduces BDNF skeletal muscle expression, with our findings identifying methylation alterations on the DNA sequence of BDNF and BDNFAS gene. Preliminary results further indicate that AEX increases methylation in BDNFAS gene, which presumably could regulate the expression of BDNF.

Background: An unsettled question in the use of robotics for post-stroke gait rehabilitation is whether task-specific locomotor training is more effective than targeting individual joint impairments to improve walking function. The paretic ankle is implicated in gait instability and fall risk, but is difficult to therapeutically isolate and refractory to recovery. We hypothesize that in chronic stroke, treadmill-integrated ankle robotics training is more effective to improve gait function than robotics focused on paretic ankle impairments., Findings: Participants with chronic hemiparetic gait were randomized to either six weeks of treadmill-integrated ankle robotics (n = 14) or dose-matched seated ankle robotics (n = 12) videogame training. Selected gait measures were collected at baseline, post-training, and six-week retention. Friedman, and Wilcoxon Sign Rank and Fisher's exact tests evaluated within and between group differences across time, respectively. Six weeks post-training, treadmill robotics proved more effective than seated robotics to increase walking velocity, paretic single support, paretic push-off impulse, and active dorsiflexion range of motion. Treadmill robotics durably improved gait dorsiflexion swing angle leading 6/7 initially requiring ankle braces to self-discarded them, while their unassisted paretic heel-first contacts increased from 44 % to 99.6 %, versus no change in assistive device usage (0/9) following seated robotics., Conclusions: Treadmill-integrated, but not seated ankle robotics training, durably improves gait biomechanics, reversing foot drop, restoring walking propulsion, and establishing safer foot landing in chronic stroke that may reduce reliance on assistive devices. These findings support a task-specific approach integrating adaptive ankle robotics with locomotor training to optimize mobility recovery., Clinical Trial Identifier: NCT01337960. https://clinicaltrials.gov/ct2/show/NCT01337960?term=NCT01337960&rank=1.

Objective: To assess the effectiveness of robotically assisted body weight supported treadmill training (RABWSTT) for improving cardiovascular fitness in chronic motor incomplete spinal cord injury (CMISCI)., Design: Pilot prospective randomized, controlled clinical trial., Setting: Outpatient rehabilitation specialty hospital., Participants: Eighteen individuals with CMISCI with American Spinal Injury Association (ASIA) level between C4 and L2 and at least one-year post injury. Interventions CMISCI participants were randomized to RABWSTT or a home stretching program (HSP) three times per week for three months. Those in the home stretching group were crossed over to three months of RABWSTT following completion of the initial three month phase., Outcome Measures: Peak oxygen consumption (peak VO(2)) was measured during both robotic treadmill walking and arm cycle ergometry: twice at baseline, once at six weeks (mid-training) and twice at three months (post-training). Peak VO(2) values were normalized for body mass., Results: The RABWSTT group improved peak VO(2) by 12.3% during robotic treadmill walking (20.2 ± 7.4 to 22.7 ± 7.5 ml/kg/min, P = 0.018), compared to a non-significant 3.9% within group change observed in HSP controls (P = 0.37). Neither group displayed a significant change in peak VO2 during arm cycle ergometry (RABWSTT, 8.5% (P = 0.25); HSP, 1.76% (P = 0.72)). A repeated measures analysis showed statistically significant differences between treatments for peak VO(2) during both robotic treadmill walking (P = 0.002) and arm cycle ergometry (P = 0.001)., Conclusion: RABWSTT is an effective intervention model for improving peak fitness levels assessed during robotic treadmill walking in persons with CMISCI.

Unlabelled: BACKGROUND. Modular lower extremity robotics may offer a valuable avenue for restoring neuromotor control after hemiparetic stroke. Prior studies show that visually guided and visually evoked practice with an ankle robot (anklebot) improves paretic ankle motor control that translates into improved overground walking., Objective: To assess the feasibility and efficacy of daily anklebot training during early subacute hospitalization poststroke., Methods: Thirty-four inpatients from a stroke unit were randomly assigned to anklebot (n = 18) or passive manual stretching (n = 16) treatments. All suffered a first stroke with residual hemiparesis (ankle manual muscle test grade 1/5 to 4/5), and at least trace muscle activation in plantar- or dorsiflexion. Anklebot training employed an "assist-as-needed" approach during >200 volitional targeted paretic ankle movements, with difficulty adjusted to active range of motion and success rate. Stretching included >200 daily mobilizations in these same ranges. All sessions lasted 1 hour and assessments were not blinded., Results: Both groups walked faster at discharge; however, the robot group improved more in percentage change of temporal symmetry (P = .032) and also of step length symmetry (P = .038), with longer nonparetic step lengths in the robot (133%) versus stretching (31%) groups. Paretic ankle control improved in the robot group, with increased peak (P ≤ .001) and mean (P ≤ .01) angular speeds, and increased movement smoothness (P ≤ .01). There were no adverse events., Conclusion: Though limited by small sample size and restricted entry criteria, our findings suggest that modular lower extremity robotics during early subacute hospitalization is well tolerated and improves ankle motor control and gait patterning., (© The Author(s) 2014.)

Purpose: This scientific statement provides an overview of the evidence on physical activity and exercise recommendations for stroke survivors. Evidence suggests that stroke survivors experience physical deconditioning and lead sedentary lifestyles. Therefore, this updated scientific statement serves as an overall guide for practitioners to gain a better understanding of the benefits of physical activity and recommendations for prescribing exercise for stroke survivors across all stages of recovery., Methods: Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statement Oversight Committee and the American Heart Association's Manuscript Oversight Committee. The writers used systematic literature reviews, references to published clinical and epidemiology studies, morbidity and mortality reports, clinical and public health guidelines, authoritative statements, personal files, and expert opinion to summarize existing evidence and indicate gaps in current knowledge., Results: Physical inactivity after stroke is highly prevalent. The assessed body of evidence clearly supports the use of exercise training (both aerobic and strength training) for stroke survivors. Exercise training improves functional capacity, the ability to perform activities of daily living, and quality of life, and it reduces the risk for subsequent cardiovascular events. Physical activity goals and exercise prescription for stroke survivors need to be customized for the individual to maximize long-term adherence., Conclusions: The recommendation from this writing group is that physical activity and exercise prescription should be incorporated into the management of stroke survivors. The promotion of physical activity in stroke survivors should emphasize low- to moderate-intensity aerobic activity, muscle-strengthening activity, reduction of sedentary behavior, and risk management for secondary prevention of stroke., (© 2014 American Heart Association, Inc.)

Background. The purpose of this study is to compare serum nutritional profiles in chronic stroke survivors to a representative sample of US Adults (NHANESIII) and determine whether these serum markers differed by race and impact physical function in stroke. Methods. Fasting serum samples were collected for analysis of lipids, uric acid, and albumin in 145 African American (AA) and 111 Caucasian (C) stroke survivors (age: 60 ± 1 years [mean ± SEM]). A six-minute walk was performed in a subset of stroke survivors (N = 134). Results. Triglycerides were higher and HDL-cholesterol and albumin lower in C than AA women stroke survivors (Ps < 0.05). Uric acid was lower in C than AA stroke survivors (P < 0.05). Compared to NHANESIII, HDL-cholesterol, albumin, and hemoglobin generally were lower (Ps < 0.05) and lipids were more favorable in stroke (Ps < 0.01). Uric acid was related to six-minute walk performance among a subset of stroke survivors (P < 0.05). Conclusion. In stroke, racial differences exist with regard to serum nutritional risk, but these differences are similar to that observed in the general population. Regardless of race, nutritional risk appears elevated above that of the general population with regard to many of the serum markers. As a modifiable biomarker, uric acid should be monitored closely as it may provide insight into the functional risk of stroke survivors.

Robotics is rapidly emerging as a viable approach to enhance motor recovery after disabling stroke. Current principles of cognitive motor learning recognize a positive relationship between reward and motor learning. Yet no prior studies have established explicitly whether reward improves the rate or efficacy of robotics-assisted rehabilitation or produces neurophysiologic adaptations associated with motor learning. We conducted a 3 wk, 9-session clinical pilot with 10 people with chronic hemiparetic stroke, randomly assigned to train with an impedance-controlled ankle robot (anklebot) under either high reward (HR) or low reward conditions. The 1 h training sessions entailed playing a seated video game by moving the paretic ankle to hit moving onscreen targets with the anklebot only providing assistance as needed. Assessments included paretic ankle motor control, learning curves, electroencephalograpy (EEG) coherence and spectral power during unassisted trials, and gait function. While both groups exhibited changes in EEG, the HR group had faster learning curves (p = 0.05), smoother movements (p

Purpose: Impaired economy of gait, prevalent in chronic stroke secondary to residual gait deficits, is associated with intolerance for performing activities of daily living. Gait economy/efficiency is traditionally assessed by determining the rate of oxygen consumption during submaximal treadmill walking. However, the mechanics and energetics of treadmill versus overground walking are very different in stroke survivors with ambulatory deficits. Clearly, overground cardiopulmonary measures are needed to accurately profile movement economy after stroke. An obstacle to obtaining such measures after stroke has been the absence of reliable portable metabolic monitoring equipment. The purpose of this study was to establish the test-retest reliability of a portable metabolic monitoring device during overground walking in hemiparetic stroke survivors., Methods: Twenty-three chronic hemiparetic stroke survivors underwent two 6-minute walk tests while wearing a COSMED K4b(2) portable metabolic measurement system. Intraclass correlations coefficients (ICC) were calculated for both cardiopulmonary parameters and distance covered to determine test-retest reliability. An ICC of ≥ 0.85 was considered reliable., Results: ICCs for relative Vo2 (0.90), absolute Vo2 (0.93), Vco2 (0.93), and minute ventilation (0.95) demonstrated high reliability, but not for heart rate (0.76) or respiratory exchange ratio (0.64). There was no significant difference in the distance each participant walked between the first and second tests, eliminating distance as a potential confounder of our analyses (ICC = 0.99)., Conclusions: Our results strongly support the reliability of the K4b(2) for quantifying overground gait efficiency after stroke. Use of this device may enable researchers to study how varying poststroke rehabilitation interventions affect this central measure of health and function.

Mechanical impedance of the ankle is known to influence key aspects of ankle function. We investigated the effects of robot-assisted ankle training in people with chronic stroke on the paretic ankle's passive stiffness and its relationship to overground gait function. Over 6 wk, eight participants with residual hemiparetic deficits engaged in a visuomotor task while seated that required dorsiflexion (DF) or plantar flexion (PF) of their paretic ankle with an ankle robot ("anklebot") assisting as needed. Passive ankle stiffness (PAS) was measured in both the trained sagittal and untrained frontal planes. After 6 wk, the PAS decreased in both DF and PF and reverted into the variability of age-matched controls in DF. Changes in PF PAS correlated strongly with gains in paretic step lengths (Spearman rho = -0.88, p = 0.03) and paretic stride lengths (Spearman rho = -0.82, p = 0.05) during independent floor walking. Moreover, baseline PF PAS were correlated with gains in paretic step lengths (Spearman rho = 0.94, p = 0.01), paretic stride lengths (Spearman rho = 0.83, p = 0.05), and single-support stance duration (Spearman rho = 0.94, p = 0.01); and baseline eversion PAS were correlated with gains in cadence (Spearman rho = -0.88, p = 0.03). These findings suggest that ankle robot-assisted, visuomotor-based, isolated ankle training has a positive effect on paretic ankle PAS that strongly influences key measures of gait function.

Background and Objective: Ambulatory subjects after stroke may benefit from gait-oriented cardiovascular fitness training, but trials to date have not primarily assessed older persons., Methods: Thirty-eight subjects (age >60 years) with residual hemiparetic gait were enrolled >6 months after stroke. Participants were randomized to receive 3 months (3×/week) progressive graded, high-intensity aerobic treadmill exercise (TAEX) or conventional care physiotherapy. Primary outcome measures were peak exercise capacity (Vo(2peak)) and sustained walking capacity in 6-minute walks (6MW). Secondary measures were gait velocity in 10-m walks, Berg Balance Scale, functional leg strength (5 chair-rise), self-rated mobility (Rivermead Mobility Index), and quality of life (SF-12)., Results: Thirty-six participants completed the study (18 TAEX, 18 controls). TAEX but not conventional care improved Vo(2peak) (difference 6.4 mL/kg/min, P < .001) and 6MW (53 m, P < .001). Likewise, maximum walking speed (0.13 m/s, P = .01), balance (P < .05), and the mental subscore of the SF-12 (P < .01) improved more after TAEX. Gains in Vo(2peak) correlated with the degree at which training intensity could be progressed in the individual participant (P < .01). Better walking was related to progression in treadmill velocity and training duration (P < .001). Vo(2peak) and 6MW performances were still higher 1 year after the end of training when compared with the baseline, although endurance walking (6MW) at 1 year was lower than immediately after training (P < .01)., Conclusion: This trial demonstrates that TAEX effectively improves cardiovascular fitness and gait in persons with chronic stroke.

The Unified Parkinson's Disease Rating Scale (UPDRS) is a widely applied index of disease severity. Our objective was to assess the utility of UPDRS for predicting peak aerobic capacity (VO2 peak) and ambulatory function. Participants (n = 70) underwent evaluation for UPDRS (Total and Motor ratings), VO2 peak, 6-minute walk distance (6MW), and 30-foot self-selected walking speed (SSWS). Using regression, we determined the extent to which the Total and Motor UPDRS scores predicted each functional capacity measure after adjusting for age and sex. We also tested whether adding the Hoehn and Yahr scale (H-Y) to the model changed predictive power of the UPDRS. Adjusted for age and sex, both the Total UPDRS and Motor UPDRS subscale failed to predict VO2 peak. The Total UPDRS did weakly predict 6MW and SSWS (both p < 0.05), but the Motor UPDRS subscale did not predict these ambulatory function tests. After adding H-Y to the model, Total UPDRS was no longer an independent predictor of 6MW but remained a predictor of SSWS. We conclude that Total and Motor UPDRS rating scales do not predict VO2 peak, but that a weak relationship exists between Total UPDRS and measures of ambulatory function.

Changes in the biomechanics of gait may alter the energy requirements of walking in Parkinson's Disease (PD). This study investigated economy of gait during submaximal treadmill walking in 79 subjects with mild to moderate PD and the relationship between gait economy and 6-minute walk distance (6 MW). Oxygen consumption (VO(2)) at the self-selected treadmill walking speed averaged 64% of peak oxygen consumption (VO(2) peak). Submaximal VO(2) levels exceeded 70% of VO(2) peak in 30% of the subjects. Overall the mean submaximal VO(2) was 51% higher than VO(2) levels expected for the speed and grade consistent with severe impairment in economy of gait. There was an inverse relationship between economy of gait and 6MW (r = -0.31, P < 0.01) and with the self-selected walking speed (r = -0.35, P < 0.01). Thus, the impairment in economy of gait and decreased physiologic reserve result in routine walking being performed at a high percentage of VO(2) peak.

Purpose: Maximal or peak aerobic capacity (VO(2peak)) during a maximal-effort graded exercise test is considered by many to be the "gold standard" outcome for assessing the effect of exercise training on cardiorespiratory fitness. The reliability of this measure in Parkinson disease (PD) has not been established, where the degree of motor impairment can vary greatly and is influenced by medications. This study examined the reliability of VO(2peak) during a maximal-effort graded exercise test in subjects with PD., Methods: Seventy healthy middle-aged and older subjects with PD Hoehn and Yahr stage 1.5-3 underwent a screening/acclimatization maximal-effort treadmill test followed by two additional maximal-effort treadmill tests with repeated measurements of VO(2peak). A third VO(2peak) test was performed in a subset of 21 subjects., Results: The mean VO(2peak) measurement was 2.4% higher in the second test compared with the first test (21.42 ± 4.3 vs 21.93 ± 4.50 mL·kg(-1)·min(-1), mean ± SD, P = 0.03). The intraclass correlation coefficients (ICC) for VO(2peak) expressed either as milliliters per kilogram per minute or as liters per minute were highly reliable, with ICC of 0.90 and 0.94, respectively. The maximum HR (ICC of 0.91) and final speed achieved during the tests (ICC of 0.94) were also highly reliable, with the respiratory quotient being the least reliable of the parameters measured (ICC of 0.65)., Conclusions: Our results demonstrate that measurement of VO(2peak) is reliable and repeatable in subjects with mild to moderate PD, thereby validating use of this parameter for assessing the effects of exercise interventions on cardiorespiratory fitness.

Background and Purpose: Animal studies provide strong evidence that aerobic exercise training positively influences cerebral blood flow, but no human studies support the use of exercise for improving cerebral hemodynamics. This randomized study in stroke survivors assessed the effects of treadmill aerobic exercise training (TM) on cerebral blood flow parameters compared to a control intervention of nonaerobic stretching., Methods: Thirty-eight participants (19 in TM group and 19 in control group) with remote stroke (>6 months) and mild to moderate gait deficits completed middle cerebral artery blood flow velocity measurements by transcranial Doppler ultrasonography before and after a 6-month intervention period. Middle cerebral artery blood flow velocity was assessed bilaterally during normocapnia and hypercapnia (6% CO2). Cerebral vasomotor reactivity (cVMR) was calculated as percent change in middle cerebral artery blood flow velocity from normocapnia to hypercapnia (cVMR percent) and as an index correcting percent change for absolute increase in end tidal CO2 (cVMR index)., Results: The TM group had significantly larger improvements than did controls for both ipsilesional and contralesional cVMR index (P≤0.05) and contralesional cVMR percent (P≤0.01). Statin users in the TM group (n=10) had higher baseline cVMR and lower training-induced cVMR change, indicating that cVMR change among those not using statins (n=9) primarily accounted for the between-group effects. There was a 19% increase in Vo2 peak for the TM group compared to a 4% decrease in the control group (P<0.01), and peak fitness change correlated with cVMR change (r=0.55; P<0.05)., Conclusions: Our data provide the first evidence to our knowledge of exercise-induced cVMR improvements in stroke survivors, implying a protective mechanism against recurrent stroke and other brain-related disorders. Statin use appears to regulate cVMR and the cVMR training response.

Background: Task-oriented therapies such as treadmill exercise can improve gait velocity after stroke, but slow velocities and abnormal gait patterns often persist, suggesting a need for additional strategies to improve walking., Objectives: To determine the effects of a 6-week visually guided, impedance controlled, ankle robotics intervention on paretic ankle motor control and gait function in chronic stroke., Methods: This was a single-arm pilot study with a convenience sample of 8 stroke survivors with chronic hemiparetic gait, trained and tested in a laboratory. Subjects trained in dorsiflexion-plantarflexion by playing video games with the robot during three 1-hour training sessions weekly, totaling 560 repetitions per session. Assessments included paretic ankle ranges of motion, strength, motor control, and overground gait function., Results: Improved paretic ankle motor control was seen as increased target success, along with faster and smoother movements. Walking velocity also increased significantly, whereas durations of paretic single support increased and double support decreased., Conclusions: Robotic feedback training improved paretic ankle motor control with improvements in floor walking. Increased walking speeds were comparable with reports from other task-oriented, locomotor training approaches used in stroke, suggesting that a focus on ankle motor control may provide a valuable adjunct to locomotor therapies.

Our objective in this study was to assess passive mechanical stiffness in the ankle of chronic hemiparetic stroke survivors and to compare it with those of healthy young and older (age-matched) individuals. Given the importance of the ankle during locomotion, an accurate estimate of passive ankle stiffness would be valuable for locomotor rehabilitation, potentially providing a measure of recovery and a quantitative basis to design treatment protocols. Using a novel ankle robot, we characterized passive ankle stiffness both in sagittal and in frontal planes by applying perturbations to the ankle joint over the entire range of motion with subjects in a relaxed state. We found that passive stiffness of the affected ankle joint was significantly higher in chronic stroke survivors than in healthy adults of a similar cohort, both in the sagittal as well as frontal plane of movement, in three out of four directions tested with indistinguishable stiffness values in plantarflexion direction. Our findings are comparable to the literature, thus indicating its plausibility, and, to our knowledge, report for the first time passive stiffness in the frontal plane for persons with chronic stroke and older healthy adults.

Background and Purpose: This randomized controlled trial tests the efficacy of bilateral arm training with rhythmic auditory cueing (BATRAC) versus dose-matched therapeutic exercises (DMTEs) on upper-extremity (UE) function in stroke survivors and uses functional magnetic resonance imaging (fMRI) to examine effects on cortical reorganization., Methods: A total of 111 adults with chronic UE paresis were randomized to 6 weeks (3×/week) of BATRAC or DMTE. Primary end points of UE assessments of Fugl-Meyer UE Test (FM) and modified Wolf Motor Function Test Time (WT) were performed 6 weeks prior to and at baseline, after training, and 4 months later. Pretraining and posttraining, fMRI for UE movement was evaluated in 17 BATRAC and 21 DMTE participants., Results: The improvements in UE function (BATRAC: FM Δ = 1.1 + 0.5, P = .03; WT Δ = -2.6 + 0.8, P < .00; DMTE: FM Δ = 1.9 + 0.4, P < .00; WT Δ = -1.6 + 0.7; P = .04) were comparable between groups and retained after 4 months. Satisfaction was higher after BATRAC than DMTE (P = .003). BATRAC led to significantly higher increase in activation in ipsilesional precentral, anterior cingulate and postcentral gyri, and supplementary motor area and contralesional superior frontal gyrus (P < .05). Activation change in the latter was correlated with improvement in the WMFT (P = .01)., Conclusions: BATRAC is not superior to DMTE, but both rehabilitation programs durably improve motor function for individuals with chronic UE hemiparesis and with varied deficit severity. Adaptations in brain activation are greater after BATRAC than DMTE, suggesting that given similar benefits to motor function, these therapies operate through different mechanisms.

Cerebrovascular accident (stroke) often results in impaired motor control and persistent weakness that may lead to chronic disability, including deficits in gait and balance function. Finding ways to restore motor control may help reduce these deficits; however, little is known regarding the capacity or temporal profile of short-term motor adaptations and learning at the hemiparetic ankle. Our objective was to determine the short-term effects of a single session of impedance-controlled ankle robot ("anklebot") training on paretic ankle motor control in chronic stroke. This was a double-arm pilot study on a convenience sample of participants with chronic stroke (n = 7) who had residual hemiparetic deficits and an equal number of age- and sex-matched nondisabled control subjects. Training consisted of participants in each group playing a target-based video game with the anklebot for an hour, for a total of 560 movement repetitions in dorsiflexion/plantar flexion ranges followed by retest 48 hours later. Task difficulty was adjusted to ankle range of motion, with robotic assistance decreased incrementally across training. Assessments included robotic measures of ankle motor control on unassisted trials before and after training and at 48 hours after training. Following exposure to the task, subjects with stroke improved paretic ankle motor control across a single training session as indexed by increased targeting accuracy (21.6 +/- 8.0 to 31.4 +/- 4.8, p = 0.05), higher angular speeds (mean: 4.7 +/- 1.5 degrees/s to 6.5 +/- 2.6 degrees/s, p < 0.01, peak: 42.8 +/- 9.0 degrees/s to 45.6 +/- 9.4 degrees/s, p = 0.03), and smoother movements (normalized jerk: 654.1 +/- 103.3 s(-2) to 537.6 +/- 86.7 s(-2), p < 0.005, number of speed peaks: 27.1 +/- 5.8 to 23.7 +/- 4.1, p < 0.01). In contrast, nondisabled subjects did not make statistically significant gains in any metric after training except in the number of successful passages (32.3 +/- 7.5 to 36.5 +/- 6.4, p = 0.006). Gains in all five motor control metrics were retained (p > 0.05) at 48 hours in both groups. Robust maintenance of motor adaptation in the robot-trained paretic ankle over 48 hours may be indicative of short-term motor learning. Our initial results suggest that the anklebot may be a flexible motor learning platform with the potential to detect rapid changes in ankle motor performance poststroke.

Background: Aerobic treadmill exercise (T-EX) therapy has been shown to benefit walking and cardiorespiratory fitness in stroke survivors with chronic gait impairment even long after their stroke. The response, however, varies between individuals., Objective: The purpose of this post hoc analysis of 2 randomized controlled T-EX trials was to identify predictors for therapy response., Methods: In all, 52 participants received T-EX for 3 (Germany) or 6 (United States) months. Improvements in overground walking velocity (10 m/6-min walk) and fitness (peak VO(2)) were indicators of therapy response. Lesion location and volume were measured on T1-weighted magnetic resonance scans., Results: T-EX significantly improved gait and fitness, with gains in 10-m walk tests ranging between +113% and -25% and peak VO(2) between -12% and 88%. Baseline walking impairments or fitness deficits were not predictive of therapy response; 10-m walk velocity improved more in those with subcortical rather than cortical lesions and in patients with smaller lesions. Improvements in 6-minute walk velocity were greater in those with more recent strokes and left-sided lesions. No variable other than training intensity, which was different between trials, predicted fitness gains., Conclusions: Despite proving overall effectiveness, the response to T-EX varies markedly between individuals. Whereas intensity of aerobic training seems to be an important predictor of gains in cardiovascular fitness, lesion size and location as well as interval between stroke onset and therapy delivery likely affect therapy response. These findings may be used to guide the timing of training and identify subgroups of patients for whom training modalities could be optimized.

Background: Cognitive deficits impede stroke recovery. Aerobic exercise (AEX) improves cognitive executive function (EF) processes in healthy individuals, although the learning benefits after stroke are unknown., Objective: To understand AEX-induced improvements in EF, motor learning, and mobility poststroke., Methods: Following cardiorespiratory testing, 38 chronic stroke survivors were randomized to 2 different groups that exercised 3 times a week (45-minute sessions) for 8 weeks. The AEX group (n = 19; 9 women; 10 men; 64.10 +/- 12.30 years) performed progressive resistive stationary bicycle training at 70% maximal heart rate, whereas the Stretching Exercise (SE) group (n = 19; 12 women; 7 men; 58.96 +/- 14.68 years) performed stretches at home. Between-group comparisons were performed on the change in performance at "Post" and "Retention" (8 weeks later) for neuropsychological and motor function measures., Results: VO(2)max significantly improved at Post with AEX (P = .04). AEX also improved motor learning in the less-affected hand, with large effect sizes (Cohen's d calculation). Specifically, AEX significantly improved information processing speed on the serial reaction time task (SRTT; ie, "procedural motor learning") compared with the SE group at Post (P = .024), but not at Retention. Also, at Post (P = .038), AEX significantly improved predictive force accuracy for a precision grip task requiring attention and conditional motor learning of visual cues. Ambulation and sit-to-stand transfers were significantly faster in the AEX group at Post (P = .038), with balance control significantly improved at Retention (P = .041). EF measurements were not significantly different for the AEX group., Conclusion: AEX improved mobility and selected cognitive domains related to motor learning, which enhances sensorimotor control after stroke.

Background and Purpose: Insulin resistance and glucose intolerance are highly prevalent after stroke, contributing to worsening cardiovascular disease risk and a predisposition to recurrent stroke. Treadmill exercise training (T-AEX) increases aerobic capacity (Vo(2) peak) in chronic stroke patients, suggesting intensity levels that may be adequate to improve glucose metabolism. We compared the effects of a progressive T-AEX intervention to an attention-matched stretching intervention (CONTROL) on glucose tolerance and indices of insulin sensitivity in stroke survivors., Methods: Participants had hemiparetic gait after remote (>6 months) ischemic stroke. They were randomized to 6-month T-AEX or a duration matched reference CONTROL program of supervised stretching exercises. Main outcome measures were glucose and insulin responses during a 3-hour oral glucose tolerance test (OGTT)., Results: Forty-six subjects (T-AEX=26, CONTROL=20) completed OGTT testing before and after the interventions. T-AEX increased Vo(2) peak (+15% versus -3% Delta, P<0.01) compared with CONTROL. There were significant reductions in fasting insulin (-23% versus +9% Delta, P<0.05) and the total integrated 3-hour insulin response (-24% versus +3% Delta, P<0.01) in T-AEX compared with CONTROL. In patients with abnormal glucose tolerance at baseline, T-AEX resulted in a significant 14% decrease in 3-hour glucose response (n=12, P<0.05). Fifty-eight percent of T-AEX participants with abnormal baseline OGTT (7 of 12) improved glucose tolerance status at 2 hours compared with <10% (1 of 11) of impaired CONTROLS (P<0.05)., Conclusions: These preliminary findings suggest that progressive aerobic exercise can reduce insulin resistance and prevent diabetes in hemiparetic stroke survivors. Larger clinical trials are needed to definitively establish the use of structured exercise training for stimulating metabolic improvement poststroke.

Objectives: To test the hypothesis that quantitative measures of cardiovascular fitness and ambulatory function differ in Black and White hemiparetic stroke survivors., Design: Cross-sectional analysis., Setting: Outpatient academic medical center., Participants: Total of 118 hemiparetic stroke survivors., Main Outcome Measures: Cardiovascular fitness was measured as VO2 peak and ambulatory function using the six-minute walk distance and 30-foot walking velocity in medically screened, community-dwelling stroke survivors., Results: In 118 subjects (56% Black and 44% White), no differences were seen in 1) VO2 peak between Black or White men (15.0+/-4.3 vs. 15.1+/-3.9 mL/kg/minute) or women (11.5+/-2.7 vs. 12.3+/-3.7 mL/kg/minute); 2) six-minute walk distance between Black or White men (223+/-112 m vs 226+/-132 m) or women (198+/-100 vs 157+/-93 m); or 3) 30-foot walking velocity between Black or White men (0.60+/-0.27 m/second vs 0.61+/-0.31 m/ second) or women (0.50+/-0.21 m/second vs 0.41+/-0.23 m/second)., Conclusion: No racial differences were seen in the degree of physical deconditioning in a selected population of community dwelling hemiparetic stroke survivors.