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Advances in medical management of Parkinson's disease (PD) have resulted in living longer with disability. Although disability worsens over the course of the disease, there are signs of disability even in the early stages. Several studies reveal an early decline in gait and balance and a high prevalence of nonmotor signs in the prodromal period that contribute to early disability. There is a growing body of evidence revealing the benefits of physical therapy and exercise to mitigate motor and nonmotor signs while improving physical function and reducing disability. The presence of early disability coupled with the benefits of exercise suggests that physical therapy should be initiated earlier in the disease. In this review, we present the evidence revealing early disability in PD and the effectiveness of physical therapy and exercise, followed by a discussion of a secondary prevention model of rehabilitation to reduce early disability and optimize long-term outcomes. [ABSTRACT FROM AUTHOR]

Digital therapeutics, treatments delivered remotely and enabled by modern technology, facilitate the provision of personalized, evidence-based, interdisciplinary interventions to manage the complexities associated with Parkinson's disease. In the context of the COVID-19 pandemic, the need for digital therapeutics has arguably never been greater. However, despite new advances in technology and a heightened interest due to the pandemic, digital therapeutics remain underdeveloped and underutilized. In this paper, we briefly review practical applications and emerging advances in digital therapeutic platforms that target motor and non-motor signs and healthy lifestyle behaviors such as regular exercise, a healthful diet and optimal sleep hygiene habits. Future applications which could transform personalized self-management and patient care are presented. Opportunities, drawbacks and barriers to access are discussed. [ABSTRACT FROM AUTHOR]

Background Declining physical activity commonly occurs in people with Parkinson disease (PD) and contributes to reduced functional capacity and quality of life. Objective The purpose of this study was to explore the preliminary effectiveness, safety, and acceptability of a mobile health (mHealth)–mediated exercise program designed to promote sustained physical activity in people with PD. Design This was a 12-month single-blind (assessor), pilot, comparative-effectiveness, randomized controlled study. Methods An mHealth-mediated exercise program (walking with a pedometer plus engagement in planned exercise supported by a mobile health application) was compared over 1 year with an active control condition (walking with a pedometer and exercise only). There were 51 participants in a community setting with mild-to-moderately severe (Hoehn and Yahr stages 1–3) idiopathic PD. Daily steps and moderate-intensity minutes were measured using a step activity monitor for 1 week at baseline and again at 12 months. Secondary outcomes included the 6-Minute Walk Test, Parkinson Disease Questionnaire 39 mobility domain, safety, acceptability, and adherence. Results Both groups increased daily steps, moderate-intensity minutes, and 6-Minute Walk Test, with no statistically significant between-group differences observed. In the less active subgroup, changes in daily steps and moderate-intensity minutes were clinically meaningful. An improvement in the Parkinson Disease Questionnaire 39 mobility score favored mHealth in the overall comparison and was statistically and clinically meaningful in the less active subgroup. Limitations The limitation of the current study was the small sample size. Conclusions Both groups improved physical activity compared with expected activity decline over 1 year. The addition of the mHealth app to the exercise intervention appeared to differentially benefit the more sedentary participants. Further study in a larger group of people with low activity at baseline is needed. [ABSTRACT FROM AUTHOR]

Introduction: The temporal relationship between disease and disability progression in Parkinson disease (PD) is not well understood. Our objective was to describe the natural, multidimensional trajectory of disability in persons with PD over a two-year period.Methods: We conducted a multi-center, prospective cohort study involving four institutions. Data were collected at baseline and at 6-month intervals over 2 years using standardized clinical tests representing three World Health Organization defined disability domains: impairment, activity limitation, and participation restriction. Unadjusted mixed effects growth models characterized trajectories of disability in the three disability domains. The data set was analyzed using restricted maximum likelihood (REML) estimation. Standardized estimates of change were also computed using Cohen's d for each measure.Results: Of the 266 enrolled participants, we analysed data from individuals who participated in at least 3 assessments (n = 207, 79%). Rates of disability progression over the 2-year period differed across domains. Moderate effects were detected for motor impairment (d = .28) and walking-related activity limitation (gait-related balance (d = .31); gait speed (d = .30)). Marginal effects were noted for upper extremity-related activity limitation (d = .11) and health-related quality of life participation restriction (d = .08).Conclusions: The natural trajectory of walking-related activity limitation was the most potent indicator of evolving disability, suggesting that routine assessment of walking and periodic rehabilitation is likely to be warranted for many persons with PD. Natural trajectories of disability provide important comparison data for future intervention studies. [ABSTRACT FROM AUTHOR]

Background: Parkinson's disease (PD) is a complex neurodegenerative disorder impacting everyday function and quality of life. Rehabilitation plays a crucial role in improving symptoms, function, and quality of life and reducing disability, particularly given the lack of disease-modifying agents and limitations of medications and surgical therapies. However, rehabilitative care is under-recognized and under-utilized in PD and often only utilized in later disease stages, despite research and guidelines demonstrating its positive effects. Currently, there is a lack of consensus regarding fundamental topics related to rehabilitative services in PD. Objective: The goal of the international Parkinson's Foundation Rehabilitation Medicine Task Force was to develop a consensus statement regarding the incorporation of rehabilitation in PD care. Methods: The Task Force, comprised of international multidisciplinary experts in PD and rehabilitation and people directly affected by PD, met virtually to discuss topics such as rehabilitative services, existing therapy guidelines and rehabilitation literature in PD, and gaps and needs. A systematic, interactive, and iterative process was used to develop consensus-based statements on core components of PD rehabilitation and discipline-specific interventions. Results: The expert-based consensus statement outlines key tenets of rehabilitative care including its multidisciplinary approach and discipline-specific guidance for occupational therapy, physical therapy, speech language pathology/therapy, and psychology/neuropsychology across all PD stages. Conclusions: Rehabilitative interventions should be an essential component in the comprehensive treatment of PD, from diagnosis to advanced disease. Greater education and awareness of the benefits of rehabilitative services for people with PD and their care partners, and further evidence-based and scientific study are encouraged. [ABSTRACT FROM AUTHOR]

Background. Declining ambulatory activity represents an important facet of disablement in Parkinson disease (PD). Objective. The primary study aim was to compare the 2-year trajectory of ambulatory activity decline with concurrently evolving facets of disability in a small cohort of people with PD. The secondary aim was to identify baseline variables associated with ambulatory activity at 1- and 2-year follow-up assessments. Design. This was a prospective, longitudinal cohort study. Methods. Seventeen people with PD (Hoehn and Yahr stages 1 -3) were recruited from 2 outpatient settings. Ambulatory activity data were collected at baseline and at 1- and 2-year annual assessments. Motor, mood, balance, gait, upper extremity function, quality of life, self-efficacy, and levodopa equivalent daily dose data and data on activities of daily living also were collected. Results. Participants displayed significant 1- and 2-year declines in the amount and intensity of ambulator)' activity concurrently with increasing levodopa equivalent daily dose. Worsening motor symptoms and slowing of gait were apparent only after 2 years. Concurrent changes in the remaining clinical variables were not observed. Baseline ambulatory activity and physical performance variables had the strongest relationships with 1- and 2-year mean daily steps. Limitations. The sample was small and homogeneous. Conclusions. Future research that combines ambulatory activity monitoring with a broader and more balanced array of measures would further illuminate the dynamic interactions among evolving facets of disablement and help determine the extent to which sustained patterns of recommended daily physical activity might slow the rate of disablement in PD. [ABSTRACT FROM AUTHOR]

Background. Environmental and task modifications are powerful methods used to affect action in rehabilitation and are frequently used by therapists. Objective. The purpose of this study was to examine and quantify the relationship between hand size (person characteristics) and object size (environmental characteristics) and the effect of this relationship on the emergent reaching patterns for children and adults with typical development. Design. This was a cross-sectional prospective study. Methods. Seventeen children and 20 adults participated and were required to reach and grasp 10 pairs of cubes of different sizes. The dimensionless ratios were calculated by dividing the cube size by the aperture between index finger and thumb to quantify emergent reach and grasp patterns. A critical ratio was used to establish the shift from a 1-handed to an exclusive 2-handed reach pattern. Results. The results demonstrated no significant difference in the mean critical ratios between the 2 groups. However, a 2-handed reach was used more frequently than a 1-handed reach at a significantly smaller ratio for children in comparison with adults. Limitations. The relational metrics between the cube and hand are only one contribution to the emergent reaching and grasping patterns. Conclusions. Children had more variability of reaching patterns than adults. A personal constraint, such as experience, and a task constraint of accuracy may account for the variability. The results encourage further research on body-scaled information for individuals with different personal constraints (eg, children with cerebral palsy) and the impact of body-scaled information on emergent actions. [ABSTRACT FROM AUTHOR]

A clinical practice guideline on Parkinson disease was developed by an American Physical Therapy Association volunteer guideline development group that consisted of physical therapists and a neurologist. The guideline was based on systematic reviews of current scientific and clinical information and accepted approaches for management of Parkinson disease. The Spanish version of this clinical practice guideline is available as a supplement (Suppl. Appendix 1). [ABSTRACT FROM AUTHOR]

Objective: The burden of PD extends beyond physical limitations and includes significant psychosocial adjustments as individuals undergo changes to their self-perception and how others perceive them. There is limited quantitative evidence of the factors that contribute to self-perceived stigma, which we addressed in the present study.Methods: In 362 individuals with PD (157 women, 205 men), self-perceived stigma was measured by the four-item stigma subscale of the Parkinson's Disease Questionnaire (PDQ-39). Hierarchical linear modeling was used to assess predictors of stigma including demographics (age, gender) and disease characteristics: duration, stage (Hoehn & Yahr Scale), motor severity (Unified Parkinson's Disease Rating Scale, UPDRS, Part 3), activities of daily living (UPDRS Part 2), and depression (Geriatric Depression Scale). Predictor variables were chosen based on their significant correlations with the stigma subscale. Further analyses were conducted for men and women separately.Results: For the total sample, the full model accounted for 14% of the variance in stigma perception (p < .001). Younger age and higher depression scores were the only significant predictors (both p < .001). This pattern was also seen for the men in the sample. For the women, only depression was a significant predictor. Depression mediated the relation between stigma and activities of daily living.Conclusions: Younger age (men) and depression (men and women) were the primary predictors of self-perceived stigma in PD. Disease characteristics (motor and ADL) did not contribute to stigma perception. Depression is a potential treatment target for self-perceived stigma in PD. [ABSTRACT FROM AUTHOR]

Introduction: High-intensity gait training is widely recognized as an effective rehabilitation approach after stroke. Soft robotic exosuits that enhance post-stroke gait mechanics have the potential to improve the rehabilitative outcomes achieved by high-intensity gait training. The objective of this development-of-concept pilot crossover study was to evaluate the outcomes achieved by high-intensity gait training with versus without soft robotic exosuits. Methods: In this 2-arm pilot crossover study, four individuals post-stroke completed twelve visits of speed-based, high-intensity gait training: six consecutive visits of Robotic Exosuit Augmented Locomotion (REAL) gait training and six consecutive visits without the exosuit (CONTROL). The intervention arms were counterbalanced across study participants and separated by 6 + weeks of washout. Walking function was evaluated before and after each intervention using 6-minute walk test (6MWT) distance and 10-m walk test (10mWT) speed. Moreover, 10mWT speeds were evaluated before each training visit, with the time-course of change in walking speed computed for each intervention arm. For each participant, changes in each outcome were compared to minimal clinically-important difference (MCID) thresholds. Secondary analyses focused on changes in propulsion mechanics and associated biomechanical metrics. Results: Large between-group effects were observed for 6MWT distance (d = 1.41) and 10mWT speed (d = 1.14). REAL gait training resulted in an average pre-post change of 68 ± 27 m (p = 0.015) in 6MWT distance, compared to a pre-post change of 30 ± 16 m (p = 0.035) after CONTROL gait training. Similarly, REAL training resulted in a pre-post change of 0.08 ± 0.03 m/s (p = 0.012) in 10mWT speed, compared to a pre-post change of 0.01 ± 06 m/s (p = 0.76) after CONTROL. For both outcomes, 3 of 4 (75%) study participants surpassed MCIDs after REAL training, whereas 1 of 4 (25%) surpassed MCIDs after CONTROL training. Across the training visits, REAL training resulted in a 1.67 faster rate of improvement in walking speed. Similar patterns of improvement were observed for the secondary gait biomechanical outcomes, with REAL training resulting in significantly improved paretic propulsion for 3 of 4 study participants (p < 0.05) compared to 1 of 4 after CONTROL. Conclusion: Soft robotic exosuits have the potential to enhance the rehabilitative outcomes produced by high-intensity gait training after stroke. Findings of this development-of-concept pilot crossover trial motivate continued development and study of the REAL gait training program. [ABSTRACT FROM AUTHOR]

Background: Reduced motor automaticity in Parkinson's disease (PD) negatively impacts the quality, intensity, and amount of daily walking. Rhythmic auditory stimulation (RAS), a clinical intervention shown to improve walking outcomes, has been limited by barriers associated with the need for ongoing clinician input. Objective: To assess the feasibility, proof-of-concept, and preliminary clinical outcomes associated with delivering an autonomous music-based digital walking intervention based on RAS principles to persons with PD in a naturalistic setting. Methods: Twenty-three persons with PD used the digital intervention independently for four weeks to complete five weekly 30-minute sessions of unsupervised, overground walking with music-based cues. The intervention progressed autonomously according to real-time gait sensing. Feasibility of independent use was assessed by examining participant adherence, safety, and experience. Intervention proof-of-concept was assessed by examining spatiotemporal metrics of gait quality, daily minutes of moderate intensity walking, and daily steps. Preliminary clinical outcomes were assessed following intervention completion. Results: Participants completed 86.4% of sessions and 131.1% of the prescribed session duration. No adverse events were reported. Gait speed, stride length, and cadence increased within sessions, and gait variability decreased (p < 0.05). Compared to baseline, increased daily moderate intensity walking (mean Δ= +21.44 minutes) and steps (mean Δ= +3,484 steps) occurred on designated intervention days (p < 0.05). Quality of life, disease severity, walking endurance, and functional mobility were improved after four weeks (p < 0.05). Conclusions: Study findings supported the feasibility and potential clinical utility of delivering an autonomous digital walking intervention to persons with PD in a naturalistic setting. [ABSTRACT FROM AUTHOR]

Background: Soft robotic exosuits can provide partial dorsiflexor and plantarflexor support in parallel with paretic muscles to improve poststroke walking capacity. Previous results indicate that baseline walking ability may impact a user's ability to leverage the exosuit assistance, while the effects on continuous walking, walking stability, and muscle slacking have not been evaluated. Here we evaluated the effects of a portable ankle exosuit during continuous comfortable overground walking in 19 individuals with chronic hemiparesis. We also compared two speed-based subgroups (threshold: 0.93 m/s) to address poststroke heterogeneity. Methods: We refined a previously developed portable lightweight soft exosuit to support continuous overground walking. We compared five minutes of continuous walking in a laboratory with the exosuit to walking without the exosuit in terms of ground clearance, foot landing and propulsion, as well as the energy cost of transport, walking stability and plantarflexor muscle slacking. Results: Exosuit assistance was associated with improvements in the targeted gait impairments: 22% increase in ground clearance during swing, 5° increase in foot-to-floor angle at initial contact, and 22% increase in the center-of-mass propulsion during push-off. The improvements in propulsion and foot landing contributed to a 6.7% (0.04 m/s) increase in walking speed (R2 = 0.82). This enhancement in gait function was achieved without deterioration in muscle effort, stability or cost of transport. Subgroup analyses revealed that all individuals profited from ground clearance support, but slower individuals leveraged plantarflexor assistance to improve propulsion by 35% to walk 13% faster, while faster individuals did not change either. Conclusions: The immediate restorative benefits of the exosuit presented here underline its promise for rehabilitative gait training in poststroke individuals. [ABSTRACT FROM AUTHOR]

Chronic impairment in the paretic ankle following stroke often requires that individuals use compensatory patterns such as asymmetric propulsion to achieve effective walking speeds needed for community engagement. Ankle exosuit assistance can provide ankle biomechanical benefit in the lab, but such environments inherently limit the amount of practice available. Community walking studies without exosuits can provide massed practice and benefit walking speed but are limited in their ability to assist proper mechanics. In this study, we combined the positive aspects of community training with those of exosuit assistance. We developed and evaluated a community Robotic Exosuit Augmented Locomotion (cREAL) program. Four participants in the chronic stage of stroke independently used our community ankle exosuit for walking in the community 3–5 days/week for 4 weeks. We performed lab evaluations before and after the 4‐week program. Two participants significantly improved their unassisted paretic propulsion by an average of 27% after the program and walked on average 4001 steps/day more in the week following the program. Despite the small number of participants, this study provides preliminary evidence for the potential of exosuits to augment gait training and rehabilitation in the community. [ABSTRACT FROM AUTHOR]

Background: Individualized, targeted, and intense training is the hallmark of successful gait rehabilitation in people post-stroke. Specifically, increasing use of the impaired ankle to increase propulsion during the stance phase of gait has been linked to higher walking speeds and symmetry. Conventional progressive resistance training is one method used for individualized and intense rehabilitation, but often fails to target paretic ankle plantarflexion during walking. Wearable assistive robots have successfully assisted ankle-specific mechanisms to increase paretic propulsion in people post-stroke, suggesting their potential to provide targeted resistance to increase propulsion, but this application remains underexamined in this population. This work investigates the effects of targeted stance-phase plantarflexion resistance training with a soft ankle exosuit on propulsion mechanics in people post-stroke. Methods: We conducted this study in nine individuals with chronic stroke and tested the effects of three resistive force magnitudes on peak paretic propulsion, ankle torque, and ankle power while participants walked on a treadmill at their comfortable walking speeds. For each force magnitude, participants walked for 1 min while the exosuit was inactive, 2 min with active resistance, and 1 min with the exosuit inactive, in sequence. We evaluated changes in gait biomechanics during the active resistance and post-resistance sections relative to the initial inactive section. Results: Walking with active resistance increased paretic propulsion by more than the minimal detectable change of 0.8 %body weight at all tested force magnitudes, with an average increase of 1.29 ± 0.37 %body weight at the highest force magnitude. This improvement corresponded to changes of 0.13 ± 0.03 N m kg− 1 in peak biological ankle torque and 0.26 ± 0.04 W kg− 1 in peak biological ankle power. Upon removal of resistance, propulsion changes persisted for 30 seconds with an improvement of 1.49 ± 0.58 %body weight after the highest resistance level and without compensatory involvement of the unresisted joints or limb. Conclusions: Targeted exosuit-applied functional resistance of paretic ankle plantarflexors can elicit the latent propulsion reserve in people post-stroke. After-effects observed in propulsion highlight the potential for learning and restoration of propulsion mechanics. Thus, this exosuit-based resistive approach may offer new opportunities for individualized and progressive gait rehabilitation. [ABSTRACT FROM AUTHOR]

Objective: The study examined how clinically measured walking capacity contributes to real-world walking performance in persons with Parkinson's disease (PD).Methods: Cross-sectional baseline data (n = 82) from a PD clinical trial were analyzed. The 6-Minute Walk Test (6MWT) and 10-Meter Walk Test (10MWT) were used to generate capacity metrics of walking endurance and fast gait speed, respectively. An activity monitor worn for seven days was used to generate performance metrics of mean daily steps and weekly moderate intensity walking minutes. Univariate linear regression analyses were used to examine associations between each capacity and performance measure in the full sample and less and more active subgroups.Results: Walking capacity significantly contributed to daily steps in the full sample (endurance: R2=.13, p < .001; fast gait speed: R2=.07, p = .017) and in the less active subgroup (endurance: R2 =.09, p = .045). Similarly, walking capacity significantly contributed to weekly moderate intensity minutes in the full sample (endurance: R2=.13, p < .001; fast gait speed: R2=.09, p = .007) and less active subgroup (endurance: R2 = .25, p < .001; fast gait speed: R2 =.21, p = .007). Walking capacity did not significantly contribute to daily steps or moderate intensity minutes in the more active subgroup.Conclusions: Walking capacity contributed to, but explained a relatively small portion of the variance in, real-world walking performance. The contribution was somewhat greater in less active individuals. The study adds support to the idea that clinically measured walking capacity may have limited benefit for understanding real-world walking performance in PD. Factors beyond walking capacity may better account for actual walking behavior. [ABSTRACT FROM AUTHOR]

In addition to the classic motor symptoms, Parkinson's disease (PD) is associated with a variety of nonmotor symptoms that significantly reduce quality of life, even in the early stages of the disease. There is an urgent need to develop evidence-based treatments for these symptoms, which include mood disturbances, cognitive dysfunction, and sleep disruption. We focus here on exercise interventions, which have been used to improve mood, cognition, and sleep in healthy older adults and clinical populations, but to date have primarily targeted motor symptoms in PD. We synthesize the existing literature on the benefits of aerobic exercise and strength training on mood, sleep, and cognition as demonstrated in healthy older adults and adults with PD, and suggest that these types of exercise offer a feasible and promising adjunct treatment for mood, cognition, and sleep difficulties in PD. Across stages of the disease, exercise interventions represent a treatment strategy with the unique ability to improve a range of nonmotor symptoms while also alleviating the classic motor symptoms of the disease. Future research in PD should include nonmotor outcomes in exercise trials with the goal of developing evidence-based exercise interventions as a safe, broad-spectrum treatment approach to improve mood, cognition, and sleep for individuals with PD. [ABSTRACT FROM AUTHOR]

Objective: Academic physical therapy has no universal metrics by which educational programs can measure outcomes, limiting their ability to benchmark to their own historical performance, to peer institutions, or to other health care professions. The PT-Graduation Questionnaire (GQ) survey, adapted from the Association of American Medical Colleges' GQ, addresses this gap by offering both inter-professional insight and fine-scale assessment of physical therapist education. This study reports the first wave of findings from an ongoing multi-site trial of the PT-GQ among diverse academic physical therapy programs, including (1) benchmarks for academic physical therapy, and (2) a comparison of the physical therapist student experience to medical education benchmarks. Methods: Thirty-four doctor of physical therapy (DPT) programs (13.2% nationwide sample) administered the online survey to DPT graduates during the 2019 to 2020 academic year. PT-GQ and Association of American Medical Colleges data were contrasted via Welch's unequal-variance t test and Hedges g (effect size). Results: A total of 1025 respondents participated in the study (response rate: 63.9%). The average survey duration was 31.8 minutes. Overall educational satisfaction was comparable with medicine, and respondents identified areas of curricular strength (eg, anatomy) and weakness (eg, pharmacology). DPT respondents provided higher ratings of faculty professionalism than medicine, lower rates of student mistreatment, and a lesser impact of within-program diversity on their training. One-third of respondents were less than "satisfied" with student mental health services. DPT respondents reported significantly higher exhaustion but lower disengagement than medical students, along with lower tolerance for ambiguity. Of DPT respondents who reported educational debt, one-third reported debt exceeding $150,000, the threshold above which the DPT degree loses economic power. Conclusions: These academic benchmarks, using the PT-GQ, provided insight into physical therapist education and identified differences between physical therapist and medical student perceptions. Impact: This ongoing trial will establish a comprehensive set of benchmarks to better understand academic physical therapy outcomes. [ABSTRACT FROM AUTHOR]

Objective: Functional near-infrared spectroscopy (fNIRS) is a non-invasive functional neuroimaging method that takes advantage of the optical properties of hemoglobin to provide an indirect measure of brain activation via task-related relative changes in oxygenated hemoglobin (HbO). Its advantage over fMRI is that fNIRS is portable and can be used while walking and talking. In this study, we used fNIRS to measure brain activity in prefrontal and motor region of interests (ROIs) during single- and dual-task walking, with the goal of identifying neural correlates. Participants and Methods: Nineteen healthy young adults [mean age=25.4 (SD=4.6) years; 14 female] engaged in five tasks: standing single-task cognition (serial-3 subtraction); single-task walking at a self-selected comfortable speed on a 24.5m oval-shaped course (overground walking) and on a treadmill; and dual-task cognition+walking on the same overground course and treadmill (8 trials/condition: 20 seconds standing rest, 30 seconds task). Performance on the cognitive task was quantified as the number of correct subtractions, number of incorrect subtractions, number of self-corrected errors, and percent accuracy over the 8 trials. Walking speed (m/sec) was recorded for all walking conditions. fNIRS data were collected on a system consisting of 16 sources, 15 detectors, and 8 short-separation detectors in the following ROIs: right and left lateral frontal (RLF, LLF), right and left medial frontal (RMF, LMF), right and left medial superior frontal (RMSF, LMSF), and right and left motor (RM, LM). Lateral and medial refer to ROIs' relative positions on lateral prefrontal cortex. fNIRS data were analyzed in Homer3 using a spline motion correction and the iterative weighted least squares method in the general linear model. Correlations between the cognitive/speed variables and ROI HbO data were applied using a Bonferroni adjustment for multiple comparisons. Results: Subjects with missing cognitive data were excluded from analyses, resulting in sample sizes of 18 for the single-task cognition, dual-task overground walking, and dual-task treadmill walking conditions. During dual-task overground walking, there was a significant positive correlation between walking speed and relative change in HbO in RMSF [r(18)=.51, p<.05] and RM [r(18)=.53, p<.05)]. There was a significant negative correlation between total number of correct subtractions and relative change in HbO in LMSF ([r(18)=-.75, p<.05] and LM [r(18)=-.52, p<.05] during dual-task overground walking. No other significant correlations were identified. Conclusions: These results indicate that there is lateralization of the cognitive and motor components of overground dual-task walking. The right hemisphere appears to be more active the faster people walk during the dual-task. By contrast, the left hemisphere appears to be less active when people are working faster on the cognitive task (i.e., serial-3 subtraction). The latter results suggest that automaticity of the cognitive task (i.e., more total correct subtractions) is related to decreased brain activity in the left hemisphere. Future research will investigate whether there is a change in cognitive automaticity over trials and if there are changes in lateralization patterns in neurodegenerative disorders that are known to differentially affect the hemispheres (e.g., Parkinson's disease). [ABSTRACT FROM AUTHOR]

Background: Parkinson disease (PD) is a debilitating and chronic neurodegenerative disease resulting in ambulation difficulties. Natural walking activity often declines early in disease progression despite the relative stability of motor impairments. In this study, we propose a paradigm shift with a "connected behavioral approach" that targets real-world walking using cognitive-behavioral training and mobile health (mHealth) technology.Methods/design: The Walking and mHealth to Increase Participation in Parkinson Disease (WHIP-PD) study is a twelve-month, dual site, two-arm, randomized controlled trial recruiting 148 participants with early to mid-stage PD. Participants will be randomly assigned to connected behavioral or active control conditions. Both conditions will include a customized program of goal-oriented walking, walking-enhancing strengthening exercises, and eight in-person visits with a physical therapist. Participants in the connected behavioral condition also will (1) receive cognitive-behavioral training to promote self-efficacy for routine walking behavior and (2) use a mHealth software application to manage their program and communicate remotely with their physical therapist. Active control participants will receive no cognitive-behavioral training and manage their program on paper. Evaluations will occur at baseline, three-, six-, and twelve-months and include walking assessments, self-efficacy questionnaires, and seven days of activity monitoring. Primary outcomes will include the change between baseline and twelve months in overall amount of walking activity (mean number of steps per day) and amount of moderate intensity walking activity (mean number of minutes per day in which > 100 steps were accumulated). Secondary outcomes will include change in walking capacity as measured by the six-minute walk test and ten-meter walk test. We also will examine if self-efficacy mediates change in amount of walking activity and if change in amount of walking activity mediates change in walking capacity.Discussion: We expect this study to show the connected behavioral approach will be more effective than the active control condition in increasing the amount and intensity of real-world walking activity and improving walking capacity. Determining effective physical activity interventions for persons with PD is important for preserving mobility and essential for maintaining quality of life. Clinical trials registration NCT03517371, May 7, 2018.Trial Registration: ClinicalTrials.gov: NCT03517371. Date of registration: May 7, 2018. Protocol version: Original. [ABSTRACT FROM AUTHOR]

Gait impairments are among the most common and disabling symptoms of Parkinson's disease. Nonetheless, gait is not routinely assessed quantitatively but is described in general terms that are not sensitive to changes ensuing with disease progression. Quantifying multiple gait features (eg, speed, variability, and asymmetry) under natural and more challenging conditions (eg, dual-tasking, turning, and daily living) enhanced sensitivity of gait quantification. Studies of neural connectivity and structural network topology have provided information on the mechanisms of gait impairment. Advances in the understanding of the multifactorial origins of gait changes in patients with Parkinson's disease promoted the development of new intervention strategies, such as neurostimulation and virtual reality, aimed at alleviating gait impairments and enhancing functional mobility. For clinical applicability, it is important to establish clear links between specific gait impairments, their underlying mechanisms, and disease progression to foster the acceptance and usability of quantitative gait measures as outcomes in future disease-modifying clinical trials. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) side of motor symptom onset has been associated with distinct cognitive deficits; individuals with left-side onset (LPD) show more visuospatial impairments, whereas those with right-side onset (RPD) show more verbal impairments. Non-spatial attention is a critical cognitive ability associated with motor functioning that is right hemisphere lateralized but has not been characterized with regard to PD side of onset. We compared individuals with LPD and RPD on non-spatial attention tasks and examined differential responses to a 4-week sustained attention training program. Participants included 9 with LPD and 12 with RPD, who performed both brief and extended go/no-go continuous performance tasks and an attentional blink task. Participants also engaged in an at-home sustained attention training program, Tonic and Phasic Alertness Training (TAPAT), 5 days/week for 4 weeks. We assessed cognitive and motor symptoms before and after training, and after a 4-week no-contact period. At baseline, participants with LPD exhibited worse performance than those with RPD on the extended continuous performance task, indicating specific deficits in sustaining attention. Poorer attention was associated with worse clinical motor scores. Notably, side of onset had a significant effect on clinical motor changes after sustained attention training, with only LPD participants improving after training, and 4/9 showing clinically meaningful improvements. Compared to RPD, participants with LPD had poorer sustained attention pre-training and were more likely to improve on clinical motor functioning after sustained attention training. These findings support mechanistic differences between LPD and RPD and suggest potential differential treatment approaches. • Question: Does sustained attention training benefit people with Parkinson's disease with left (LPD) more than right (RPD) side onset?. • Findings: At baseline, LPD exhibited poorer attention than RPD; after training, improved motor functioning was found only in LPD. • Importance: Without separating LPD and RPD, the positive effect of attention training in LPD would have been missed. • Next steps: Future work should examine the association between attention and motor function in hemiPD in regard to interventions. [ABSTRACT FROM AUTHOR]

Stroke-induced hemiparetic gait is characteristically asymmetric and metabolically expensive. Weakness and impaired control of the paretic ankle contribute to reduced forward propulsion and ground clearance - walking subtasks critical for safe and efficient locomotion. Targeted gait interventions that improve paretic ankle function after stroke are thereforewarranted. We have developed textile-based, soft wearable robots that transmit mechanical power generated by off-board or body-worn actuators to the paretic ankle using Bowden cables (soft exosuits) and have demonstrated the exosuits can overcome deficits in paretic limb forward propulsion and ground clearance, ultimately reducing the metabolic cost of hemiparetic walking. This study elucidates the biomechanical mechanisms underlying exosuit-induced reductions in metabolic power. We evaluated the relationships between exosuit-induced changes in the body center of mass (COM) power generated by each limb, individual joint power and metabolic power. Compared with walking with an exosuit unpowered, exosuit assistance produced more symmetrical COM power generation during the critical period of the step-to-step transition (22.4±6.4% more symmetric). Changes in individual limb COM power were related to changes in paretic (R²=0.83, P=0.004) and non-paretic (R²=0.73, P=0.014) ankle power. Interestingly, despite the exosuit providing direct assistance to only the paretic limb, changes in metabolic power were related to changes in non-paretic limb COM power (R²=0.80, P=0.007), not paretic limb COM power (P>0.05). These findings contribute to a fundamental understanding of how individuals post-stroke interact with an exosuit to reduce the metabolic cost of hemiparetic walking. [ABSTRACT FROM AUTHOR]

Objective: Functional near-infrared spectroscopy (fNIRS) is a non-invasive functional neuroimaging method that indirectly measures cortical activation via task-related changes in oxygenated hemoglobin (HbO). We used fNIRS during a working memory task to assess learning effect over time by assessing brain activity (fNIRS signal) and task performance. We hypothesized that in later blocks of the task, learning (better accuracy) would be correlated to less increase in HbO in prefrontal regions, indicating improved cognitive efficiency. Method: Eighteen healthy adults [mean age = 24.9 (SD = 4.2); 14 female] engaged in 8 blocks of serial-3 subtraction for 30 seconds each followed by 20 seconds of rest. fNIRS data were collected in 8 cortical regions of interest (ROI) broadly covering the frontal lobe. fNIRS signal in each ROI and task-performance data were compared for the first 4 and last 4 blocks to examine learning. Results: fNIRS signal was significantly greater for the first 4 than last 4 blocks (z = −2.1, p < 0.05) in only the right dorsolateral prefrontal cortex ROI. No learning effects appeared for any task-performance variables. Conclusions: These results indicate a dissociation between brain activity and task performance during a working memory task in healthy adults. There was less activity in the right dorsolateral prefrontal cortex during later than earlier trials, indicating an increase in this region's efficiency, without a change in task performance. The results suggest that fNIRS may be sensitive to change in brain activity before it appears clinically, which may be useful in studying people with conditions such as preclinical Alzheimer's disease, and in assessing subtle effects of interventions. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study was to evaluate the effects on common poststroke gait compensations of a soft wearable robot (exosuit) designed to assist the paretic limb during hemiparetic walking. Design: A single-session study of eight individuals in the chronic phase of stroke recovery was conducted. Two testing conditions were compared: walking with the exosuit powered versus walking with the exosuit unpowered. Each condition was 8 minutes in duration. Results: Compared with walking with the exosuit unpowered, walking with the exosuit powered resulted in reductions in hip hiking (27[6%], P = 0.004) and circumduction (20[5%], P = 0.004). A relationship between changes in knee flexion and changes in hip hiking was observed (Pearson r = -0.913,P<0.001). Similarly, multivariate regression revealed that changes in knee flexion (β = -0.912,P=0.007), but not ankle dorsiflexion (β = -0.194, P = 0.341), independently predicted changes in hip hiking (R² = 0.87, F(2, 4) = 13.48, P = 0.017). Conclusions: Exosuit assistance of the paretic limb during walking produces immediate changes in the kinematic strategy used to advance the paretic limb. Future work is necessary to determine how exosuit-induced reductions in paretic hip hiking and circumduction during gait training could be leveraged to facilitate more normal walking behavior during unassisted walking. [ABSTRACT FROM AUTHOR]

We investigated the relationships between average gait speed collected with the 10Meter Walk Test (Comfortable and Fast) and 6Minute Walk Test (6MWT) in 346 people with Parkinson disease (PD) and how the relationships change with increasing disease severity. Pearson correlation and linear regression analyses determined relationships between 10Meter Walk Test and 6MWT gait speed values for the entire sample and for sub-samples stratified by Hoehn & Yahr (H&Y) stage I (n=53), II (n=141), III (n=135) and IV (n=17). We hypothesized that redundant tests would be highly and significantly correlated (i.e. r>0.70, p<0.05) and would have a linear regression model slope of 1 and intercept of 0. For the entire sample, 6MWT gait speed was significantly (p<0.001) related to the Comfortable 10 Meter Walk Test (r=0.75) and Fast 10Meter Walk Test (r=0.79) gait speed, with 56% and 62% of the variance in 6MWT gait speed explained, respectively. The regression model of 6MWT gait speed predicted by Comfortable 10 Meter Walk gait speed produced slope and intercept values near 1 and 0, respectively, especially for participants in H&Y stages II-IV. In contrast, slope and intercept values were further from 1 and 0, respectively, for the Fast 10Meter Walk Test. Comfortable 10 Meter Walk Test and 6MWT gait speeds appeared to be redundant in people with moderate to severe PD, suggesting the Comfortable 10 Meter Walk Test can be used to estimate 6MWT distance in this population. [ABSTRACT FROM AUTHOR]

The Parkinson's Foundation sought to develop Parkinson's specific competencies for exercise professionals who work with people with Parkinson's (PwP). These competencies built upon exercise guidelines and professional competencies for healthy populations. The purpose of this article is to describe the development of the professional competencies, continuing education criteria, and a pilot accreditation process. Competency development included: (1) an expert panel conducting an environmental scan, within the USA, related to exercise professional education in Parkinson's and synthesizing Parkinson's-specific exercise guidelines, (2) surveying people with Parkinson's in the USA, and (3) developing the competencies and curriculum criteria with psychometricians. A pilot accreditation process for Parkinson's exercise educational programs and continuing education courses includes an application, baseline, 6- and 12-month assessments. Activities reported here did not require ethical review. The survey was approved by NORC at the University of Chicago's Institutional Review Board (IRB). The environmental scan, exercise guidelines, and survey (n = 627) informed competency development. The five key condition-specific domains were: (1) foundational information on the disease and role of exercise, (2) exercise screening, (3) group and individual exercise design, (4) behavior and counseling for exercise, and (5) interprofessional communication and program development. Seven applicants were accredited as certification programs (n = 3) or continuing education courses (n = 4). The competencies, curriculum criteria, and accreditation processes support exercise professionals working with PwP. Reducing variation in the knowledge and skills of exercise professionals can improve the safe implementation and effectiveness of exercise programs, which are a critical part of integrated plan for people with Parkinson's disease (PD). • Exercise professionals are key Parkinson's team members, who provide exercise leadership, social support, and motivation. • Developing professional competencies will reduce variability in the delivery of exercise to people with Parkinson's. • Cirricula criteria for Parkinson's exercise professionals' education should address their heterogeneous backgrounds. [ABSTRACT FROM AUTHOR]

We determined the number of days required, and whether to include weekdays and/or weekends, to obtain reliable measures of ambulatory physical activity in people with Parkinson's disease (PD). Ninety-two persons with PD wore a step activity monitor for seven days. The number of days required to obtain a reliable estimate of daily activity was determined from the mean intraclass correlation (ICC2,1) for all possible combinations of 1-6 consecutive days of monitoring. Two days of monitoring were sufficient to obtain reliable daily activity estimates (ICC2,1 > 0.9). Amount (p = 0.03) but not intensity (p = 0.13) of ambulatory activity was greater on weekdays than weekends. Activity prescription based on amount rather than intensity may be more appropriate for people with PD. [ABSTRACT FROM AUTHOR]

Veering while walking is often reported in individuals with Parkinson's disease (PD), with potential mechanisms being vision-based (asymmetrical perception of the visual environment) or motoric (asymmetry in stride length between relatively affected and non-affected body side). We examined these competing hypotheses by assessing veering in 13 normal control participants (NC) and 20 non-demented individuals with PD: 9 with left-side onset of motor symptoms (LPD) and 11 with right-side onset (RPD). Participants walked in a corridor under three conditions: eyes-open, egocentric reference point (ECRP; walk toward a subjectively perceived center of a target at the end of the corridor), and vision-occluded. The visual hypothesis predicted that LPD participants would veer rightward, in line with their rightward visual-field bias, whereas those with RPD would veer leftward. The motor hypothesis predicted the opposite pattern of results, with veering toward the side with shorter stride length. Results supported the visual hypothesis. Under visual guidance, RPD participants significantly differed from NC, veering leftward despite a shorter right- than left-stride length, whereas LPD veered rightward (not significantly different from NC), despite shorter left- than right-stride length. LPD participants showed significantly reduced rightward veering and stride asymmetry when they walked in the presence of a visual landmark (ECRP) than in the eyes-open condition without a target. There were no group differences in veering in the vision-occluded condition. The findings suggest that interventions to correct walking abnormalities such as veering in PD should incorporate vision-based strategies rather than solely addressing motor asymmetries, and should be tailored to the distinctive navigational profiles of LPD and RPD. [ABSTRACT FROM AUTHOR]

Background: Freezing of gait (FOG) is a relatively common and remarkably disabling impairment associated with Parkinson disease (PD). Laboratory-based measures indicate that individuals with FOG (PD+FOG) have greater balance deficits than those without FOG (PD-FOG). Whether such differences also can be detected using clinical balance tests has not been investigated. We sought to determine if balance and specific aspects of balance, measured using Balance Evaluation Systems Test (BESTest), differs between PD+FOG and PD-FOG. Furthermore, we aimed to determine if time-efficient clinical balance measures (i.e. Mini-BESTest, Berg Balance Scale (BBS)) could detect balance differences between PD+FOG and PD-FOG.Methods: Balance of 78 individuals with PD, grouped as either PD+FOG (n=32) or PD-FOG (n=46), was measured using the BESTest, Mini-BESTest, and BBS. Between-groups comparisons were conducted for these measures and for the six sections of the BESTest using analysis of covariance. A PD composite score was used as a covariate.Results: Controlling for motor sign severity, PD duration, and age, PD+FOG had worse balance than PD-FOG when measured using the BESTest (p=0.008, F=7.35) and Mini-BESTest (p=0.002, F=10.37), but not the BBS (p=0.27, F=1.26). BESTest section differences were noted between PD+FOG and PD-FOG for reactive postural responses (p<0.001, F=14.42) and stability in gait (p=0.003, F=9.18).Conclusions: The BESTest and Mini-BESTest, which specifically assessed reactive postural responses and stability in gait, were more likely than the BBS to detect differences in balance between PD+FOG and PD-FOG. Because it is more time efficient to administer, the Mini-BESTest may be the preferred tool for assessing balance deficits associated with FOG. [ABSTRACT FROM AUTHOR]

Background Assessment of fall risk in an individual with Parkinson disease (PD) is a critical yet often time consuming component of patient care. Recently a simple clinical prediction tool based only on fall history in the previous year, freezing of gait in the past month, and gait velocity <1.1 m/s was developed and accurately predicted future falls in a sample of individuals with PD. METHODS: We sought to externally validate the utility of the tool by administering it to a different cohort of 171 individuals with PD. Falls were monitored prospectively for 6 months following predictor assessment. RESULTS: The tool accurately discriminated future fallers from non-fallers (area under the curve [AUC] = 0.83; 95% CI 0.76–0.89), comparable to the developmental study. CONCLUSION: The results validated the utility of the tool for allowing clinicians to quickly and accurately identify an individual's risk of an impending fall. [ABSTRACT FROM AUTHOR]

Background: The natural progression of balance decline in individuals with Parkinson disease (PD) is not well understood. Objectives: We aimed to: 1) compare the utility of three standardized clinical measures for detecting balance decline over 1-year, 2) identify components of balance susceptible to decline, and 3) identify factors useful for predicting future balance decline. Methods: Eighty people with PD (59% male; mean age 68.2 ± 9.3; Hoehn & Yahr range I-IV) completed Balance Evaluation Systems Test (BESTest), Mini-BESTest, and Berg Balance Scale (BBS) assessments. Baseline predictor variables included the MDS-UPDRS III sub-score, presence of freezing, 6-month fall history, age, gender, and physical activity. Balance and MDS-UPDRS III assessments were repeated at 6 (n = 51) and 12 months (n = 44). Results: BESTest and Mini-BESTest score declined over 6 and 12 months (P < 0.01). Postural responses, stability limits, and sensory orientation were most susceptible to decline. BBS score did not change (P > 0.01). MDS-UPDRS III score was unchanged over 6 months (P > 0.01), but declined over 12 months (P < 0.01). Change in BESTest score over 6 months was related to baseline MDS-UPDRS III, H&Y, freezing, and fall history (P < 0.05). Change in BESTest score over 12 months was related to baseline MDS-UPDRS III and freezing (P < 0.05). Change in Mini-BESTest over 12 months was related to baseline MDS-UPDRS III and age (P < 0.05). Conclusions: The BESTest and Mini-BESTest were responsive to balance decline in individuals with PD and helped to identify decline in underlying balance components. Disease severity and freezing most consistently predicted balance decline in persons with PD. [ABSTRACT FROM AUTHOR]

A correction to the article "Physical Therapist Management of Parkinson Disease: A Clinical Practice Guideline From the American Physical Therapy Association," by J. A. Osborne at al, that was published in a 2022 issue is presented.

Background. The newly developed Brief-Balance Evaluation System Test (Brief-BESTest) may be useful for measuring balance and predicting falls in individuals with Parkinson disease (PD). Objectives. The purposes of this study were: (1) to describe the balance performance of those with PD using the Brief-BESTest, (2) to determine the relationships among the scores derived from the 3 versions of the BESTest (ie, full BESTest, Mini-BESTest, and Brief-BESTest), and (3) to compare the accuracy of the Brief- BESTest with that of the Mini-BESTest and BESTest in identifying recurrent fallers among people with PD. Design. This was a prospective cohort study. Methods. Eighty participants with PD completed a baseline balance assessment. All participants reported a fall history during the previous 6 months. Fall history was again collected 6 months (n51) and 12 months (n40) later. Results. At baseline, participants had varying levels of balance impairment, and Brief-BESTest scores were significantly correlated with Mini-BESTest (r=.94, P.001) and BESTest (r=.95, P.001) scores. Six-month retrospective fall prediction accuracy of the Brief-BESTest was moderately high (area under the curve [AUC]=0.82, sensitivity 0.76, and specificity=0.84). Prospective fall prediction accuracy over 6 months was similarly accurate (AUC=0.88, sensitivity=0.71, and specificity=0.87), but was less sensitive over 12 months (AUC0.76, sensitivity=0.53, and specificity=0.93). Limitations. The sample included primarily individuals with mild to moderate PD. Also, there was a moderate dropout rate at 6 and 12 months. Conclusions. All versions of the BESTest were reasonably accurate in identifying future recurrent fallers, especially during the 6 months following assessment. Clinicians can reasonably rely on the Brief-BESTest for predicting falls, particularly when time and equipment constraints are of concern. [ABSTRACT FROM AUTHOR]

Gait difficulties and falls are commonly reported in people with Parkinson disease (PD). Reduction in gait speed is a major characteristic of Parkinsonian gait, yet little is known about its underlying determinants, its ability to reflect an internal reservation about walking, or its relationship to falls. To study these issues, we selected age, disease severity, and nonmotor factors (i.e., depression, quality of life, balance confidence, and exercise beliefs and attitudes) to predict self-selected (SELF), fast-as-possible (FAST), and the difference (DIFF) between these walking speeds in 78 individuals with PD. We also examined gender differences in gait speeds and evaluated how gait speeds were related to a retrospective fall report. Age, disease severity, and balance confidence were strong predictors of SELF, FAST, and, to a lesser extent, DIFF. All three parameters were strongly associated with falling. DIFF was significantly greater in men compared to women and was significantly associated with male but not female fallers. The results supported the clinical utility of using a suite of gait speed parameters to provide insight into the gait difficulties and differentiating between fallers in people with PD. [ABSTRACT FROM AUTHOR]

Introduction. We analyzed the ability of four balance assessments to predict falls in people with Parkinson Disease (PD) prospectively over six and 12 months. Materials and Methods. The BESTest, Mini-BESTest, Functional Gait Assessment (FGA), and Berg Balance Scale (BBS) were administered to 80 participants with idiopathic PD at baseline. Falls were then tracked for 12 months. Ability of each test to predict falls at six and 12 months was assessed using ROC curves and likelihood ratios (LR). Results. Twenty-seven percent of the sample had fallen at six months, and 32% of the sample had fallen at 12 months. At six months, areas under the ROC curve (AUC) for the tests ranged from 0.8 (FGA) to 0.89 (BESTest) with LR+ of 3.4 (FGA) to 5.8 (BESTest). At 12 months, AUCs ranged from 0.68 (BESTest, BBS) to 0.77 (Mini-BESTest) with LR+ of 1.8 (BESTest) to 2.4 (BBS, FGA). Discussion. The various balance tests were effective in predicting falls at six months. All tests were relatively ineffective at 12 months. Conclusion. This pilot study suggests that people with PD should be assessed biannually for fall risk. [ABSTRACT FROM AUTHOR]

Background: People with Parkinson disease (PD), even in the presence of symptomatic relief from medical, surgical, and rehabilitative interventions, face a persistent worsening of disability. This disability is characterized by diminished quality of life, reduced functional mobility, declining performance in activities of daily living and worsening neurological impairments. While evidence has emerged supporting the clinically meaningful benefits of short-term exercise programs on these underlying factors, assertions regarding the effects of sustained programs of exercise and physical activity on the trajectory of disablement in PD are made in the absence of direct evidence. Indeed, the natural decline in quality of life and functional mobility in people diagnosed with PD is poorly understood. Moreover, outcome measures commonly used in clinical exercise trials typically do not capture the full spectrum of disability as defined by the World Health Organization (WHO). Methods/Design: The objective of this multicenter prospective study will be to examine the 2-year trajectory of disablement in a cohort of persons with PD. Two hundred sixty participants will be recruited to produce an expected final sample size of 150 individuals. Participants will be included if they are greater than 40 years of age, have a neurologist confirmed diagnosis of idiopathic PD, and are at Hoehn and Yahr stages 1 through 4. Data will be collected every 6 months during the study period. Primary outcome measures reflecting a broad spectrum of disablement will include, but will not be limited to, MDS-UPDRS, Timed Up and Go, Berg Balance Test, Nine Hole Peg Test, PDQ-39, and directly monitored ambulatory activity. Self-reported exercise and physical activity data also will be recorded. Statistical analyses will be used to characterize the trajectory of disablement and examine the influence of its underlying contributing factors. Discussion: Tertiary prevention is an important component of contemporary healthcare for individuals living with degenerative disease. For individuals with PD, there is growing recognition that exercise and/or physical activity efforts to slow the rate of functional mobility decline, in particular, may be critical for optimizing quality of life. By describing the natural trajectory of disablement, exercise habits, and physical activity in a cohort of persons with PD, this investigation will establish an important foundation for future intervention research. Specifically, through the evaluation of the influence of sustained exercise and physical activity on disablement, the study will serve as a preliminary step toward developing a randomized controlled trial of long-term exercise in persons with PD. [ABSTRACT FROM AUTHOR]