Older adults are impaired in the release of grip force during a force tracking task.

Age-related changes in force generation have been implicated in declines in older adult manual dexterity. While force generation is a critical aspect of the successful manipulation of objects, the controlled release of force represents the final component of dexterous activities. The impact of advancing age on the release of grip force has received relatively little investigation despite its importance in dexterity. The primary aim of this project was to determine the effects of age on the control of force release during a precision grip tracking task. Young adults (N = 10, 18-28 years) and older adults (N = 10, 57-77 years) completed a ramp-hold-release (0-35% of maximum grip force) force tracking task with their dominant hand. Compared to young adults, older adults were disproportionately less accurate (i.e., less time within target range) and had more error (i.e., greater relative root mean squared error) in the release of force, compared to generation of grip force. There was a significant difference between groups in two-point discrimination of the thumb, which was moderately correlated to force control across all phases of the task. The decline in force release performance associated with advanced age may be a result of sensory deficits and changes in central nervous system circuitry.

An 8-week Forced-rate Aerobic Cycling Program Improves Cardiorespiratory Fitness in Persons With Chronic Stroke: A Randomized Controlled Trial.

OBJECTIVE: To examine the cardiorespiratory effects of a forced-rate aerobic exercise (FE) intervention among individuals with chronic stroke compared with an upper extremity repetitive task practice (UE RTP) control group. DESIGN: Secondary analysis of data from a randomized controlled trial. SETTING: Research laboratory. PARTICIPANTS: Individuals with chronic stroke (N=60). INTERVENTIONS: Participants completed 24 sessions of FE followed by RTP (FE+RTP, N=30) or time matched RTP alone (N=30). The FE+RTP group was prescribed exercise at 60%-80% of heart rate reserve on a motorized stationary cycle ergometer for 45 minutes followed by 45 minutes of RTP. The control group completed 90 minutes of RTP. MAIN OUTCOME MEASURES: Metabolic exercise stress tests on a cycle ergometer were conducted at baseline and post-intervention. Outcomes included peak oxygen consumption (peak V̇o2) and anaerobic threshold (AT). RESULTS: Fifty participants completed the study intervention and pre/post stress tests. The FE+RTP group demonstrated significantly greater improvements in peak V̇o2 from 16.4±5.7 to 18.3±6.4 mL/min/kg compared with the RTP group (17.0±5.6 to 17.2±5.6 mL/min/kg, P=.020) and significantly greater improvements in AT from 10.3±2.8 to 11.5±3.6 mL/min/kg compared with the RTP group (10.8±3.9 to 10.4±3.2 mL/min/kg, P=.020). In analyzing predictors of post-intervention peak V̇o2, the multivariable linear regression model did not reveal a significant effect of age, sex, body mass index, or beta blocker usage. Similarly, bivariate linear regression models for the FE group only did not find any exercise variables (aerobic intensity, power, or cycling cadence) to be significant predictors of peak V̇o2. CONCLUSIONS: While the aerobic exercise intervention was integrated into rehabilitation to improve UE motor recovery, it was also effective in eliciting significant and meaningful improvements in cardiorespiratory fitness. This novel rehabilitation model may be an effective approach to improve motor and cardiorespiratory function in persons recovering from stroke.

Gait patterns during overground and virtual omnidirectional treadmill walking.

BACKGROUND: Omnidirectional treadmills (ODTs) offer a promising solution to the virtual reality (VR) locomotion problem, which describes the mismatch between visual and somatosensory information and contributes to VR sickness. However, little is known about how walking on ODTs impacts the biomechanics of gait. This project aimed to compare overground and ODT walking and turning in healthy young adults. METHODS: Fifteen young adults completed forward walk, 180° turn, and 360° turn tasks under three conditions: (1) overground, (2) on the Infinadeck ODT in a virtual environment without a handrail, and (3) on the ODT with a handrail. Kinematic data for all walking trials were gathered using 3D optical motion capture. RESULTS: Overall, gait speed was slower during ODT walking than overground. When controlling for gait speed, ODT walking resulted in shorter steps and greater variability in step length. There were no significant differences in other spatiotemporal metrics between ODT and overground walking. Turning on the ODT required more steps and slower rotational speeds than overground turns. The addition of the stability handrail to the ODT resulted in decreased gait variability relative to the ODT gait without the handrail. CONCLUSION: Walking on an ODT resembles natural gait patterns apart from slower gait speed and shorter step length. Slower walking and shorter step length are likely due to the novelty of physically navigating a virtual environment which may result in a more conservative approach to gait. Future work will evaluate how older adults and those with neurological disease respond to ODT walking.

Characterizing Heart Rate Response During Upper Extremity Repetitive Task Practice in Chronic Stroke.

IMPORTANCE: Although the cardiopulmonary benefits of aerobic exercise poststroke are well-established, typical stroke rehabilitation does not elicit an aerobic response. OBJECTIVE: To characterize heart rate response during upper extremity repetitive task practice (RTP) and determine factors that predict a higher aerobic intensity during RTP. DESIGN: Secondary analysis of a subset of data from a randomized clinical trial. SETTING: Research laboratory in a large academic medical center. PARTICIPANTS: Patients with chronic stroke (N = 19). INTERVENTION: Participants received 90 min of RTP for 24 sessions across 8 wk. OUTCOMES AND MEASURES: Aerobic intensity as measured by heart rate reserve (HRR) during RTP. RESULTS: A total of 2,968 tasks were included in the analysis. Of the tasks performed, approximately 79.5% elicited a very light aerobic response (<30% HRR), 10.2% elicited a light aerobic response (30%-39% HRR), and 10.3% elicited a moderate to vigorous intensity aerobic response (≥40% HRR). Of the tasks that elicited a moderate to vigorous intensity aerobic response, 54.1% were performed in standing, 79.7% were gross motor in nature, and 27.9% had targets at or above shoulder height. Standing position, targets at or above shoulder height, and gross motor tasks predicted higher HRR (all ps < .001). CONCLUSIONS AND RELEVANCE: To maximize aerobic intensity during poststroke RTP, therapists should include gross motor tasks trained in standing with targets at or above shoulder height. Plain-Language Summary: The study characterizes heart rate response in stroke rehabilitation and identifies factors that predict a higher aerobic intensity during upper extremity repetitive task practice. Certain task characteristics were more likely to produce an aerobic response, including gross motor, targets at or above the shoulder, and a standing position. Occupational therapists should include gross motor tasks trained in standing with targets at or above shoulder height to maximize aerobic intensity during poststroke repetitive task practice. Monitoring heart rate may improve awareness of aerobic response to training.

Individuals With Parkinson Disease Are Adherent to a High-Intensity Community-Based Cycling Exercise Program.

BACKGROUND AND PURPOSE: Parkinson disease is a progressive neurological disorder with no known cure or proven method of slowing progression. High-intensity, laboratory-based aerobic exercise interventions are currently being pursued as candidates for altering disease progression. The aim of this project was to evaluate the translation of a laboratory-based intervention to the community by monitoring exercise adherence (eg, attendance) and intensity (eg, heart rate [HR] and cadence) in 5 established Pedaling for Parkinson's exercise classes. A secondary aim was to determine the impact of disease severity and demographics variables on exercise adherence. METHODS: A 12-month pragmatic design was utilized to monitor attendance, HR, and cadence during each Pedaling for Parkinson's class session. Over the course of 1 year, approximately 130 sessions were offered. Forty-nine (n = 30 males) persons with mild to moderate Parkinson disease from 5 community fitness facilities participated. RESULTS: Out of the approximately 130 cycling sessions offered at each site over 12 months, 37% of the participants attended greater than 2 classes per week (80-130 total sessions), 47% attended 1 to 1.9 classes per week (40-79 total sessions), and less than 17% attended less than 1 class per week (<40 total sessions). Average pedaling cadence was 74.1 ± 9.6 rpms while average percentage of HR maximum was 68.9 ± 12.0%. There were no significant differences between cycling adherence and intensity variables based on disease severity, age, or sex. DISCUSSION AND CONCLUSIONS: Consistent attendance and exercise performance at moderate to high intensities are feasible in the context of a community-based Pedaling for Parkinson's class. Consistency and intensity of aerobic exercise have been proposed as critical features to elicit potential disease modification benefits associated with exercise. Community-based fitness programs that bring laboratory protocols to the "real world" are a feasible intervention to augment current Parkinson disease treatment approaches. See the Supplementary Video, available at: http://links.lww.com/JNPT/A357.

The Microsoft HoloLens 2 Provides Accurate Measures of Gait, Turning, and Functional Mobility in Healthy Adults.

Augmented-reality (AR) headsets, such as the Microsoft HoloLens 2 (HL2), have the potential to be the next generation of wearable technology as they provide interactive digital stimuli in the context of ecologically-valid daily activities while containing inertial measurement units (IMUs) to objectively quantify the movements of the user. A necessary precursor to the widespread utilization of the HL2 in the fields of movement science and rehabilitation is the rigorous validation of its capacity to generate biomechanical outcomes comparable to gold standard outcomes. This project sought to determine equivalency of kinematic outcomes characterizing lower-extremity function derived from the HL2 and three-dimensional (3D) motion capture systems (MoCap). Sixty-six healthy adults completed two lower-extremity tasks while kinematic data were collected from the HL2 and MoCap: (1) continuous walking and (2) timed up-and-go (TUG). For all the continuous walking metrics (cumulative distance, time, number of steps, step and stride length, and velocity), equivalence testing indicated that the HL2 and MoCap were statistically equivalent (error ≤ 5%). The TUG metrics, including turn duration and turn velocity, were also statistically equivalent between the two systems. The accurate quantification of gait and turning using a wearable such as the HL2 provides initial evidence for its use as a platform for the development and delivery of gait and mobility assessments, including the in-person and remote delivery of highly salient digital movement assessments and rehabilitation protocols.

Digitizing a Therapeutic: Development of an Augmented Reality Dual-Task Training Platform for Parkinson's Disease.

Augmented reality (AR) may be a useful tool for the delivery of dual-task training. This manuscript details the development of the Dual-task Augmented Reality Treatment (DART) platform for individuals with Parkinson's disease (PD) and reports initial feasibility, usability, and efficacy of the DART platform in provoking dual-task interference in individuals with PD. The DART platform utilizes the head-mounted Microsoft HoloLens2 AR device to deliver concurrent motor and cognitive tasks. Biomechanical metrics of gait and cognitive responses are automatically computed and provided to the supervising clinician. To assess feasibility, individuals with PD (N = 48) completed a bout of single-task and dual-task walking using the DART platform. Usability was assessed by the System Usability Scale (SUS). Dual-task interference was assessed by comparing single-task walking and walking during an obstacle course while performing a cognitive task. Average gait velocity decreased from 1.06 to 0.82 m/s from single- to dual-task conditions. Mean SUS scores were 81.3 (11.3), which placed the DART in the "good" to "excellent" category. To our knowledge, the DART platform is the first to use a head-mounted AR system to deliver a dual-task paradigm and simultaneously provide biomechanical data that characterize cognitive and motor performance. Individuals with PD were able to successfully use the DART platform with satisfaction, and dual-task interference was provoked. The DART platform should be investigated as a platform to treat dual-task declines associated with PD.

High intensity aerobic exercise improves information processing and motor performance in individuals with Parkinson's disease.

Parkinson's disease (PD) adversely affects information processing and motor performance. The impact of aerobic exercise on modifying the deleterious effects of PD underlying information and motor control processes is not well established. The primary aim of this project was to determine the effects of an 8-week high intensity exercise intervention on information processing and movement execution in individuals with PD. A secondary aim sought to understand the effects of antiparkinsonian medication relative to exercise on motor control processes. Data were collected at baseline (on- and off-medication) and upon completion of the exercise intervention (off-medication). Information processing and motor execution were evaluated via simple and choice reaction time paradigms (SRT and CRT) performed on a mobile device. Neither exercise nor medication impacted information processing or movement execution under the SRT paradigm. However, under CRT, exercise improved movement execution and information processing: total time was significantly reduced from 814 to 747 ms (p < 0.001), reaction time improved from 543 to 502 ms (p < 0.001), movement time improved from 270 to 246 ms (p = 0.01), and movement velocity improved from 28 cm/sec to 30 cm/sec (p = 0.01). Improvements in total time and reaction time in the CRT paradigm persisted 4 and 8 weeks following exercise cessation. Antiparkinsonian medication improved motor execution, but not information processing. The improvement in information processing following aerobic exercise, but not levodopa administration, suggests high intensity exercise may be enhancing neural processing and non-motor pathways outside those impacted by medication. The persistence of symptom improvement despite exercise intervention cessation indicates exercise is a candidate for disease modification. Trial registration: The trial was first registered at ClinicalTrials.gov on 7/10/2012 under registration number NCT01636297.

Effect of Aerobic Exercise on Cardiopulmonary Responses and Predictors of Change in Individuals With Parkinson's Disease.

OBJECTIVE: To determine the effect of aerobic exercise on maximal and submaximal cardiopulmonary responses and predictors of change in individuals with Parkinson's disease (PD). DESIGN: Single-center, parallel-group, rater-blind study. SETTING: Research laboratory. PARTICIPANTS: Individuals with mild to moderate PD (N=100). INTERVENTION: Participants were enrolled in a trial evaluating the effect of cycling on PD and randomized to either voluntary exercise (VE), forced exercise (FE), or a no exercise control group. The exercise groups were time and intensity matched and exercised 3×/wk for 8 weeks on a stationary cycle. MAIN OUTCOME MEASURES: Cardiopulmonary responses were collected via gas analysis during a maximal graded exercise test at baseline and post intervention. RESULTS: Exercise attendance was 97% and 93% for the FE and VE group, respectively. Average exercise heart rate reserve was 67%±11% for FE and 70%±10% for VE. No significant difference was present for change in peak oxygen consumption (VO2peak) post intervention, even though the FE group had a 5% increase in VO2peak. Both the FE and VE groups had significantly higher percentage oxygen consumption per unit time (V˙o2) at ventilator threshold (VT) than the control group compared with baseline values (P=.04). Mean V˙O2 at VT was 5% (95% CI, 0.1%-11%) higher in the FE group (P=.04) and 7% (2%, 12%) higher in VE group compared with controls. A stepwise linear regression model revealed that lower age, higher exercise cadence, and lower baseline VO2peak were most predictive of improved VO2peak. The overall model was found to be significant (P<.01). CONCLUSIONS: Peak and submaximal cardiopulmonary function may improve after aerobic exercise in individuals with PD. Lower age, higher exercise cadence, and lower baseline VO2peak were most predictive of improved VO2peak in this exercise cohort. The improvements observed in aerobic capacity were gained after a relatively short aerobic cycling intervention.

Forced and Voluntary Aerobic Cycling Interventions Improve Walking Capacity in Individuals With Chronic Stroke.

OBJECTIVES: To determine the efficacy of high-intensity cycling to improve walking capacity in individuals with chronic stroke, identify variables that predict improvement in walking capacity, and quantify the relationship between the 6-minute walk test (6MWT) and cardiopulmonary exercise (CPX) test variables. DESIGN: Secondary analysis of data from 2 randomized controlled trials. SETTING: Research laboratory. PARTICIPANTS: Individuals with chronic stroke (N=43). INTERVENTIONS: Participants were randomized to 1 of the following time-matched interventions, occurring 3 times per week for 8 weeks: (1) forced aerobic exercise and upper extremity repetitive task practice (FE+RTP [n=16]), (2) voluntary aerobic exercise and upper extremity repetitive task practice (VE+RTP [n=14]), or (3) a non-aerobic control group (n=13). MAIN OUTCOME MEASURE: Change in walking capacity as measured by the 6MWT from baseline to the end of treatment (EOT). RESULTS: Significant increases were observed in distance traveled during the 6MWT at the EOT compared with baseline in the FE+RTP (P<.001) and VE+RTP (P<.001) groups, but not in the control group (P=.21). Among aerobic exercise participants, a multivariate regression analysis revealed that cycling cadence, power output, and baseline 6MWT distance were significant predictors of change in walking capacity. CONCLUSIONS: An 8-week aerobic cycling intervention prescribed at 60% to 80% of heart rate reserve and moderate to high cadence and resistance led to significant improvements in walking capacity in our cohort of individuals with chronic stroke. Individuals with low baseline walking capacity levels may benefit most from aerobic cycling to improve over ground locomotion. Although the 6MWT did not elicit a cardiorespiratory response comparable to the maximal exertion CPX test, the 6MWT can be considered a valid and clinically relevant submaximal test of cardiorespiratory function in individuals with chronic stroke.

Predictors of Improved Aerobic Capacity in Individuals With Chronic Stroke Participating in Cycling Interventions.

OBJECTIVE: To determine demographic and physiological factors that predict improvement in aerobic capacity among individuals with chronic stroke participating in cycling interventions. DESIGN: Secondary analysis of data from 2 randomized clinical trials. SETTING: Research laboratory. PARTICIPANTS: Individuals with chronic stroke (N=44). INTERVENTIONS: Participants were randomized to one of the following interventions: forced aerobic exercise and upper extremity repetitive task practice (FE+UERTP, n=16), voluntary aerobic exercise and upper extremity repetitive task practice (VE+UERTP, n=15), or a nonaerobic control group (control, n=13). All interventions were time-matched and occurred 3 times per week for 8 weeks. MAIN OUTCOME MEASURE: Aerobic capacity as measured by peak oxygen consumption per unit time (VO2peak) during maximal cardiopulmonary exercise stress testing. RESULTS: Significant improvements in VO2peak were observed from baseline to postintervention in the VE+UERTP group (P<.001). Considerable variability was observed among participants relating to postintervention change in VO2peak. Among aerobic exercise participants, a multivariate regression analysis revealed that cycling cadence, baseline VO2peak, and group allocation were significant predictors of change in VO2peak. CONCLUSIONS: High exercise rate (cycling cadence) appears to be an important variable in improving aerobic capacity and should be considered when prescribing aerobic exercise for individuals with chronic stroke. Those with low VO2peak at baseline may benefit the most from aerobic interventions as it relates to cardiorespiratory fitness. Further investigation is warranted to understand the precise role of other exercise and demographic variables in the prescription of aerobic exercise for this population and their effects on secondary stroke prevention and mortality.

Functional modeling of pedaling kinematics for the Stroke patients.

Understanding deficits in motor control through the analysis of pedaling biomechanics plays a key role in the treatment of stroke patients. A thorough study of the impact of different exercise patterns and workloads on the change between pre- and post-treatment movement patterns in the patients is therefore of utmost importance to the clinicians. The objective of this study was to analyze the difference between pre- and post-treatment pedaling torques when the patients are subject to different exercise groups with varying workloads. The effects of affected vs unaffected side along with the covariates age and BMI have also been accounted for in this work. Two different three-way ANOVA-based approaches have been implemented here. In the first approach, a random projection-based ANOVA technique has been performed treating the pedaling torques as functional response, whereas the second approach utilizes distance measures to summarize the difference between pre- and post-treatment torques and perform nonparametric tests on it. Bayesian bootstrap has been used here to perform tests on the median distance. A group of stroke patients have been studied in the Cleveland Clinic categorizing them into different exercise groups and workload patterns. The data obtained have been analyzed with the aforementioned techniques, and the results have been reported here. These techniques turn out to be promising and will help clinicians recommend personalized treatment to stroke patients for optimal results.

Combined Aerobic Exercise and Task Practice Improve Health-Related Quality of Life Poststroke: A Preliminary Analysis.

OBJECTIVE: The aim of this project was to determine the effects of lower extremity aerobic exercise coupled with upper extremity repetitive task practice (RTP) on health-related quality of life (HRQOL) and depressive symptomology in individuals with chronic stroke. DESIGN: Secondary analysis of data from 2 randomized controlled trials. SETTING: Research laboratory. PARTICIPANTS: Individuals (N=40) with chronic stroke. INTERVENTIONS: Participants received one of the following interventions: forced exercise+RTP (FE+RTP, n=16), voluntary exercise+RTP (VE+RTP, n=16), or stroke education+RTP (EDU+RTP, n=8). All groups completed 24 sessions, each session lasting 90 minutes. MAIN OUTCOME MEASURES: The Center for Epidemiological Studies-Depression Scale (CES-D) and Stroke Impact Scale (SIS) were used to assess depressive symptomology and HRQOL. RESULTS: There were no significant group-by-time interactions for any of the SIS domains or composite scores. Examining the individual groups following the intervention, those in the FE+RTP and VE+RTP groups demonstrated significant improvements in the following SIS domains: strength, mobility, hand function, activities of daily living, and the physical composite. In addition, the FE+RTP group demonstrated significant improvements in memory, cognitive composite, and percent recovery from stroke. The HRQOL did not change in the EDU+RTP group. Although CES-D scores improved predominantly for those in the FE+RTP group, these improvements were not statistically significant. Overall, results were maintained at the 4-week follow-up. CONCLUSION: Aerobic exercise, regardless of mode, preceding motor task practice may improve HRQOL in patients with stroke. The potential of aerobic exercise to improve cardiorespiratory endurance, motor outcomes, and HRQOL poststroke justifies its use to augment traditional task practice.

An iPad-based Measure of Processing Speed in Older Adults Hospitalized for Heart Failure.

BACKGROUND: In older adults hospitalized with heart failure (HF), cognitive impairment is associated with increased hospital readmission and mortality risk. There is no consensus on an objective, scalable method of cognitive screening in this population. OBJECTIVE: The aim of this project was to determine the feasibility, test-retest reliability, and convergent validity of the Processing Speed Test (PST), a test of information processing, attention, and working memory administered on an iPad in older adults hospitalized with HF. METHODS: Patients hospitalized with HF (n = 30) and age-, sex-, and education-matched controls (n = 30) participated in the study. To determine test-retest reliability, the PST was administered on an iPad on 2 occasions, separated by 12 to 48 hours. The Symbol Digit Modalities Test was administered at the first testing time point to determine convergent validity. RESULTS: Test-retest reliability of the PST was 0.80 and 0.92 in individuals with HF and controls, respectively. Convergent validity was 0.72 and 0.90 for individuals with HF and controls, respectively. Time to complete the PST was similar for both individuals with HF and controls (<5 minutes). CONCLUSION: The iPad-based deployment of the PST was a feasible, reliable, and valid cognitive screen for older adults hospitalized with HF. Using a tablet-based self-administered cognitive screen in older adults with HF provides a method of cognitive assessment that is amenable to widespread clinical utilization.

The Two Minute Walk Test Overground and on a Self-Paced Treadmill Detects Dual Task Deficits in Individuals With Parkinson's Disease.

The aim of this project was to 1) evaluate the potential of the Two Minute Walk Test (2MWT) to detect declines in gait velocity under dual task conditions, and 2) compare gait velocity overground and on a self-paced treadmill in Parkinson's disease (PD). Twenty-three individuals with PD completed the 2MWT under single and dual task (serial 7s) conditions overground and on a self-paced treadmill. There was a significant decrease in gait velocity from single to dual task conditions overground (1.32±.22 m/sec to 1.10±.25 m/sec, p <.001) and on the self-paced treadmill (1.24±.21 m/sec to 1.05±.25 m/sec, p <.001). Overground and treadmill velocities were not statistically different from each other; however, differences approached or exceeded the minimal clinical important difference. The 2MWT coupled with a cognitive task provides an effective model of identifying dual task declines in individuals with PD. Further studies comparing overground and self-paced treadmill velocity is warranted in PD.

Use of Mobile Device Accelerometry to Enhance Evaluation of Postural Instability in Parkinson Disease.

OBJECTIVE: To determine the accuracy of inertial measurement unit data from a mobile device using the mobile device relative to posturography to quantify postural stability in individuals with Parkinson disease (PD). DESIGN: Criterion standard. SETTING: Motor control laboratory at a clinic. PARTICIPANTS: A sample (N=28) of individuals with mild to moderate PD (n=14) and age-matched community-dwelling individuals without PD (n=14) completed the study. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Center of mass (COM) acceleration measures were compared between the mobile device and the NeuroCom force platform to determine the accuracy of mobile device measurements during performance of the Sensory Organization Test (SOT). Analyses examined test-retest reliability of both systems and sensitivity of (1) the equilibrium score from the SOT and (2) COM acceleration measures from the force platform and mobile device to quantify postural stability across populations. RESULTS: Metrics of COM acceleration from inertial measurement unit data and the NeuroCom force platform were significantly correlated across balance conditions and groups (Pearson r range, .35 to .97). The SOT equilibrium scores failed to discriminate individuals with and without PD. However, the multiplanar measures of COM acceleration from the mobile device exhibited good to excellent reliability across SOT conditions and were able to discriminate individuals with and without PD in conditions with the greatest balance demands. CONCLUSIONS: Metrics employing medial-lateral movement produce a more sensitive outcome than the equilibrium score in identifying postural instability associated with PD. Overall, the output from the mobile device provides an accurate and reliable method of rapidly quantifying balance in individuals with PD. The portable and affordable nature of a mobile device with the application makes it ideally suited to use biomechanical data to aid in clinical decision making.

Forced Aerobic Exercise Preceding Task Practice Improves Motor Recovery Poststroke.

OBJECTIVE: To understand how two types of aerobic exercise affect upper-extremity motor recovery post-stroke. Our aims were to (1) evaluate the feasibility of having people who had a stroke complete an aerobic exercise intervention and (2) determine whether forced or voluntary exercise differentially facilitates upper-extremity recovery when paired with task practice. METHOD: Seventeen participants with chronic stroke completed twenty-four 90-min sessions over 8 wk. Aerobic exercise was immediately followed by task practice. Participants were randomized to forced or voluntary aerobic exercise groups or to task practice only. RESULTS: Improvement on the Fugl-Meyer Assessment exceeded the minimal clinically important difference: 12.3, 4.8, and 4.4 for the forced exercise, voluntary exercise, and repetitive task practice-only groups, respectively. Only the forced exercise group exhibited a statistically significant improvement. CONCLUSION: People with chronic stroke can safely complete intensive aerobic exercise. Forced aerobic exercise may be optimal in facilitating motor recovery associated with task practice.

Effect of subthalamic nucleus deep brain stimulation on dual-task cognitive and motor performance in isolated dystonia.

OBJECTIVE: Subthalamic nucleus (STN) deep brain stimulation (DBS) can improve motor complications of Parkinson's disease (PD) but may worsen specific cognitive functions. The effect of STN DBS on cognitive function in dystonia patients is less clear. Previous reports indicate that bilateral STN stimulation in patients with PD amplifies the decrement in cognitive-motor dual-task performance seen when moving from a single-task to dual-task paradigm. We aimed to determine if the effect of bilateral STN DBS on dual-task performance in isolated patients with dystonia, who have less cognitive impairment and no dementia, is similar to that seen in PD. METHODS: Eight isolated predominantly cervical patients with dystonia treated with bilateral STN DBS, with average dystonia duration of 10.5 years and Montreal Cognitive Assessment score of 26.5, completed working memory (n-back) and motor (forced-maintenance) tests under single-task and dual-task conditions while on and off DBS. RESULTS: A multivariate, repeated-measures analysis of variance showed no effect of stimulation status (On vs Off) on working memory (F=0.75, p=0.39) or motor function (F=0.22, p=0.69) when performed under single-task conditions, though as working memory task difficulty increased, stimulation disrupted the accuracy of force-tracking. There was a very small worsening in working memory performance (F=9.14, p=0.019) when moving from single-task to dual-tasks when using the 'dual-task loss' analysis. CONCLUSIONS: This study suggests the effect of STN DBS on working memory and attention may be much less consequential in patients with dystonia than has been reported in PD.

Objective assessment of postural stability in Parkinson's disease using mobile technology.

BACKGROUND: A significant gap remains in the ability to effectively characterize postural instability in individuals with Parkinson's disease. Clinical evaluation of postural declines is largely subjective, whereas objective biomechanical approaches are expensive and time consuming, thus limiting clinical adoption. Recent advances in mobile devices present an opportunity to address the gap in the quantification of postural stability. The aim of this project was to determine whether kinematic data measured by hardware within a tablet device, a 3rd generation iPad, was of sufficient quantity and quality to characterize postural stability. METHODS: Seventeen patients and 17 age-matched controls completed six balance conditions under altered surface, stance, and vision. Simultaneous kinematic measurements were gathered from a three-dimensional motion capture system and tablet. RESULTS: The motion capture system and tablet provided similar measures of stability across groups. In particular, within the patient population, correlation between the two systems for peak-to-peak, normalized path length, root mean square, 95% volume, and total power values ranged from 0.66 to 1.00. Kinematic data from five balance conditions--double-leg stance with eyes open on a foam surface, double-leg stance with eyes closed on firm and foam surfaces, and tandem stance on firm and foam surfaces--were capable of discriminating patients from controls. CONCLUSIONS: The hardware within the tablet provides data of sufficient accuracy for the quantification of postural stability in patients with Parkinson's disease. The objectivity, portability, and ease of use of this device make it ideal for use in clinical environments lacking sophisticated biomechanical systems.

The cyclical lower extremity exercise for Parkinson's trial (CYCLE): methodology for a randomized controlled trial.

BACKGROUND: Motor and non-motor impairments affect quality of life in individuals with Parkinson's disease. Our preliminary research indicates that forced exercise cycling, a mode of exercise in which a participant's voluntary rate of exercise is augmented on a stationary cycle, results in global improvements in the cardinal symptoms of Parkinson's disease. The objective of the Cyclical Lower Extremity Exercise (CYCLE) trial for Parkinson's disease is to determine the effects of forced exercise cycling on motor and non-motor performance when compared to voluntary rate cycling and a non-exercise control group. Additionally, we plan to identify any associated changes in neural activity determined by functional magnetic resonance imaging. METHODS/DESIGN: A total of 100 individuals with mild to moderate idiopathic Parkinson's disease will participate in a single-center, parallel-group, rater-blind study. Participants will be randomized 2:2:1 into a forced exercise, voluntary exercise, or no-exercise control group, respectively. Both exercise groups will cycle 3 times per week for 8 weeks at identical aerobic intensities for 40 minutes, but participants in the forced exercise group will cycle 30% faster than their voluntary rate by means of an augmented motorized bicycle. Neuroimaging, clinical, and biomechanical assessments of motor and non-motor performance will be made at baseline both 'on' and 'off' medication, after four weeks of exercise (midpoint), end of treatment, 4 weeks after end of treatment, and 8 weeks after end of treatment. DISCUSSION: CYCLE trial will play a critical role in determining the effectiveness of two different types of aerobic exercise, forced and voluntary, on motor and non-motor performance in individuals with Parkinson's disease. Additionally, the coupling of clinical, biomechanical, and neuroimaging outcomes has the potential to provide insight into mechanisms underlying change in function as a result of exercise. TRIAL REGISTRATION: Clinicaltrials.gov registration number NCT01636297.