Balance, Body Motion, and Muscle Activity After High-Volume Short-Term Dance-Based Rehabilitation in Persons With Parkinson Disease: A Pilot Study

Ethnokinesiology: towards a neuromechanical understanding of cultural differences in movement

Each individual's movements are sculpted by constant interactions between sensorimotor and sociocultural factors. A theoretical framework grounded in motor control mechanisms articulating how sociocultural and biological signals converge to shape movement is currently missing. Here, we propose a framework for the emerging field of ethnokinesiology aiming to provide a conceptual space and vocabulary to help bring together researchers at this intersection. We offer a first-level schema for generating and testing hypotheses about cultural differences in movement to bridge gaps between the rich observations of cross-cultural movement variations and neurophysiological and biomechanical accounts of movement. We explicitly dissociate two interacting feedback loops that determine culturally relevant movement: one governing sensorimotor tasks regulated by neural signals internal to the body, the other governing ecological tasks generated through actions in the environment producing ecological consequences. A key idea is the emergence of individual-specific and culturally influenced motor concepts in the nervous system, low-dimensional functional mappings between sensorimotor and ecological task spaces. Motor accents arise from perceived differences in motor concept topologies across cultural contexts. We apply the framework to three examples: speech, gait and grasp. Finally, we discuss how ethnokinesiological studies may inform personalized motor skill training and rehabilitation, and challenges moving forward.This article is part of the theme issue 'Minds in movement: embodied cognition in the age of artificial intelligence'.

Moving Towards a Medicine of Dance: A Scoping Review of Characteristics of Dance Interventions Targeting Older Adults and a Theoretical Framework

Background

Dance combines cultural and aesthetic elements with behaviors important for brain health, including physical activity, social engagement, and cognitive challenge. Therefore, dance could positively impact public health given the rapidly aging population, increasing incidence of Alzheimer's disease and related dementias, and lack of uptake of exercise in many older adults. Despite a high volume of literature, existing literature does not support evidence-based guidelines for dance to support healthy aging.

Objective

To conduct a scoping review of the dance intervention literature in older adults and provide information to facilitate a more consistent approach among scientists in designing dance interventions for older adults that stimulate physical and neurocognitive health adaptations.

Methods

Study characteristics (sample size, population, study design, outcomes, intervention details) were ascertained from 112 separate studies of dance reported in 127 papers that reported outcomes important for brain health (cardiorespiratory fitness, balance and mobility, cognition, mood, and quality of life).

Results

High heterogeneity across studies was evident. Class frequency ranged from < 1 to 5 classes per week, class length from 30-120 minutes, and intervention duration from 2 weeks to 18 months. Studies often did not randomize participants, had small (< 30) sample sizes, and used varied comparator conditions. Over 50 tests of cognition, 40 dance forms, and 30 tests of mobility were identified.

Conclusions

Based on these results, important future directions are establishing common data elements, developing intervention mapping and mechanistic modeling, and testing dosing parameters to strengthen and focus trial design of future studies and generate evidence-based guidelines for dance.

"InMotion"-Mixed physical exercise program with creative movement as an intervention for adults with schizophrenia: study protocol for a randomized controlled trial

Background

Schizophrenia is among the world's top 10 causes of long-term disability with symptoms that lead to major problems in social and occupational functioning, and in self-care. Therefore, it is important to investigate the efficacy of complementary treatment options for conventionally used antipsychotic medication, such as physical training, and psychosocial interventions.

Objective

To combine aerobic and strength training with cognitive, emotional and social stimulation in one intervention for people with schizophrenia and test the feasibility and effects of this intervention.

Methods

The study is a mixed-method randomized controlled trial to evaluate the effects of a 12-week intervention for adults with schizophrenia. The treatment group (30 participants) will receive the intervention in addition to standard care and the control group (30 participants) only standard care. The intervention consists of 24 biweekly sessions with a duration of 60 min. The pre-test (weeks from 4 to 2 prior to the intervention) and post-test (week 12) include clinical measure (PANSS), quality of life, social performance, movement quantity, brain function and eye tracking measures. In addition, a treatment subgroup of 12-15 participants and their family member or other next of kin will complete a qualitative interview as a part of their post-test. Two follow-up tests, including clinical, quality of life, brain function and eye tracking will be made at 6 and 12 months from the completion of the intervention to both study groups. The primary outcome is change in negative symptoms. Secondary outcome measures include general and positive symptoms, quality of life, social performance, movement quantity, brain function and eye tracking. Explorative outcome includes patient and family member or other next of kin interview.

Results

Pilot data was collected by June 2023 and the main data collection will begin in September 2023. The final follow-up is anticipated to be completed by 2026.

Conclusion

The InMotion study will provide new knowledge on the feasibility, efficacy, and experiences of a novel intervention for adults with schizophrenia. The hypothesis is that regular participation in the intervention will reduce clinical symptoms, normalize physiological measures such as brain activation, and contribute to new active habits for the participants.

Trial registration

ClinicalTrials.gov, identifier NCT05673941.

The Neuroscience of Dance: A Conceptual Framework and Systematic Review

Ancient and culturally universal, dance pervades many areas of life and has multiple benefits. In this article, we provide a conceptual framework and systematic review, as a guide for researching the neuroscience of dance. We identified relevant articles following PRISMA guidelines, and summarised and evaluated all original results. We identified avenues for future research in: the interactive and collective aspects of dance; groove; dance performance; dance observation; and dance therapy. Furthermore, the interactive and collective aspects of dance constitute a vital part of the field but have received almost no attention from a neuroscientific perspective so far. Dance and music engage overlapping brain networks, including common regions involved in perception, action, and emotion. In music and dance, rhythm, melody, and harmony are processed in an active, sustained pleasure cycle giving rise to action, emotion, and learning, led by activity in specific hedonic brain networks. The neuroscience of dance is an exciting field, which may yield information concerning links between psychological processes and behaviour, human flourishing, and the concept of eudaimonia.

Dance as a neurorehabilitation strategy: A systematic review

OBJECTIVE

This systematic review aimed to demonstrate the benefits of dance-based therapeutic interventions in rehabilitation processes in patients with neurological disorders.

METHODS

Searches on the following databases and electronic search engines were conducted: MEDLINE, LILACS, Science Direct, SCOPUS, PeDro, BVS (virtual health library), and Google Scholar. Data extraction was independently performed by two authors. Twenty-five clinical trial-type studies that included dance and established outcome measures were included, and studies in which a musicalized exercise modality was used without the connotation of dance were excluded.

RESULTS

From the results of multiple studies, the short-term motor benefits of rhythmic auditory stimulation on gait parameters were highlighted. Furthermore, there was scientific evidence demonstrating the benefits of the cognitive and social parameters of group dancing as significant improvements in cognitive flexibility and processing speed were highlighted. Recent studies showed that interventions based on exercise and/or rhythmic choreography can reduce the risk of falls in patients with neurological disorders, thereby improving their quality of life.

CONCLUSION

These findings suggest that dance is an innovative and effective method that can be included in therapies as it allows for a promising prognosis in motor, cognitive, and social performances of patients with neurological disorders that alter mobility and quality of life.

Unleashing the potential of dance: a neuroplasticity-based approach bridging from older adults to Parkinson's disease patients

Parkinson's disease (PD) is a neurodegenerative disorder that affects >1% of individuals worldwide and is manifested by motor symptoms such as tremor, rigidity, and bradykinesia, as well as non-motor symptoms such as cognitive impairment and depression. Non-pharmacological interventions such as dance therapy are becoming increasingly popular as complementary therapies for PD, in addition to pharmacological treatments that are currently widely available. Dance as a sensorimotor activity stimulates multiple layers of the neural system, including those involved in motor planning and execution, sensory integration, and cognitive processing. Dance interventions in healthy older people have been associated with increased activation of the prefrontal cortex, as well as enhanced functional connectivity between the basal ganglia, cerebellum, and prefrontal cortex. Overall, the evidence suggests that dance interventions can induce neuroplastic changes in healthy older participants, leading to improvements in both motor and cognitive functions. Dance interventions involving patients with PD show better quality of life and improved mobility, whereas the literature on dance-induced neuroplasticity in PD is sparse. Nevertheless, this review argues that similar neuroplastic mechanisms may be at work in patients with PD, provides insight into the potential mechanisms underlying dance efficacy, and highlights the potential of dance therapy as a non-pharmacological intervention in PD. Further research is warranted to determine the optimal dance style, intensity, and duration for maximum therapeutic benefit and to determine the long-term effects of dance intervention on PD progression.

Rationale and Design of the PARTNER Trial: Partnered Rhythmic Rehabilitation for Enhanced Motor-Cognition in Prodromal Alzheimer's Disease

BACKGROUND

Functional decline in Alzheimer's disease (AD) is impacted by impaired ability to integrate and modulate complex cognitive and motor abilities, commonly known as motor-cognitive integration. Impaired motor-cognitive integration occurs in the early stages of AD, prodromal AD (pAD), and may precede other symptoms. Combined motor and cognitive training have been recommended for people with pAD and need to be better researched. Our data suggest that partnered rhythmic rehabilitation (PRR) improves motor-cognitive integration in older adults with cognitive impairment. PRR is an ideal intervention to simultaneously target cardiovascular, social, and motor-cognitive domains important to AD.

OBJECTIVE/METHODS

We propose to conduct a 1-year Phase II, single-blind randomized controlled trial using PRR in 66 patients with pAD. Participants will be assigned to three months of biweekly sessions, followed by nine months of weekly sessions of PRR or group walking (WALK) with 1 : 1 allocation. Group walking in the control group will allow us to compare physical exercise alone versus the added benefit of the cognitively engaging elements of PRR.

RESULTS/CONCLUSION

Using an intent-to-treat approach, this innovative pilot study will 1) Determine acceptability, safety, tolerability, and satisfaction with PRR; 2) Compare efficacy of PRR versus WALK for improving motor-cognitive integration and identify the most sensitive endpoint for a Phase III trial from a set of motor-cognitive, volumetric MRI, and cognitive measures. The study will additionally explore potential neural, vascular, and inflammatory mechanisms by which PRR affects pAD to derive effect size of these intermediary measures and aid us in estimating sample size for a future trial.

Do dance style and intervention duration matter in improving balance among people with Parkinson's disease? A systematic review with meta-analysis

INTRODUCTION

Impaired balance is a common symptom that increases fall risk in people with Parkinson's disease (PwPD). Although previous meta-analyses concluded that dance-based interventions could improve balance in PwPD, they have limitations, such as small samples and low rigor. Another overlooked issue is whether the effects of dance-based interventions depend on dance style and training duration. The primary purpose of this meta-analysis was to further examine the efficacy of dance-based interventions in improving balance in PwPD. The secondary goals were to compare the intervention efficacy of different dance styles and durations.

METHODS

Fourteen randomized controlled trials (RCT) examining the effect of dance-based treatment on improving balance among 612 PwPD were included. Effect size (ES) was calculated as the standardized mean difference. Meta-analyses (one primary analysis and three subgroup analyses) were completed using random-effects models.

RESULTS

Results showed a medium overall ES of 0.57 (95% confidence interval or CI: [0.29,0.84], p < 0.0001) in favor of dance versus control on improving balance in PwPD. The subgroup analysis of six dance styles revealed various ES ranging 0.40-2.00. Balance was significantly improved with dance compared to control group for 12+ week interventions (ES = 0.72, 95%CI: [0.37,1.08], p < 0.0001). Interventions with 60- and 90-min classes produced similar ES for improving PwPD's balance (60-min ES = 0.54; 90-min ES = 0.68).

CONCLUSION

Dance-based interventions (particularly of 12+ weeks) could effectively improve balance among PwPD. More high-quality RCT are needed to determine the most beneficial dance styles and session lengths. These findings could inform future studies for designing/deploying effective dance-based balance training and fall prevention programs for PwPD.

Effects of dance on gait and dual-task gait in Parkinson's disease

BACKGROUND

Gait impairments in Parkinson's disease (PD) limit independence and quality of life. While dance-based interventions could improve gait, further studies are needed to determine if the benefits generalise to different terrains and when dual-tasking. The aim was to assess the effects of a dance intervention, based on the Dance for PD® (DfPD®) program, on gait under different dual-tasks (verbal fluency, serial subtraction) and surfaces (even, uneven), and to determine if a larger scale follow-up RCT is warranted.

METHODS

A dance group (DG; n = 17; age = 65.8 ± 11.7 years) and a control group (CG: n = 16; age = 67.0 ± 7.7 years) comprised of non-cognitively impaired (Addenbrooke's score: DG = 93.2 ± 3.6, CG = 92.6 ± 4.3) independently locomoting people with PD (Hoehn & Yahr I-III). The DG undertook a one-hour DfPD®-based class, twice weekly for 12 weeks. The CG had treatment as usual. The spatiotemporal variables of gait were assessed at baseline and post-intervention while walking on two surfaces (even, uneven) under three conditions: regular walking; dual-task: verbal-fluency (DTVERB), and serial-subtraction (DTSUBT). The data were analysed by means of a linear mixed model.

RESULTS

At baseline, there was no significant group difference for any spatiotemporal gait variable. The DG improved significantly compared to the CG with and without a dual task when walking on even surface. During regular walking, DG improved in gait velocity (p = 0.017), cadence (p = 0.039), step length (p = 0.040) and stride length (p = 0.041). During DTVERB significant improvements were noted in gait velocity (p = 0.035), cadence (p = 0.034) and step length (p = 0.039). The DG also exhibited significant improvement compared to the CG during DTSUBT in the measures of gait velocity (p = 0.012), cadence (p = 0.021), step length (p = 0.018), and stride length (p = 0.151). On the uneven surface, improvements were noted when walking while performing serial subtractions only. During regular walking, improvements were noted for the CG but not for the DG. CG has spent less time in double support following the intervention than DG. While DTVERB condition had no significant group differences for any gait parameter (p's >0.05), in the DTSUBT condition, the DG improved significantly compared to the controls on gait velocity (p = 0.048), cadence (p = 0.026), and step length (p = 0.051).

CONCLUSIONS

DfPD®-based classes produced clinically significant improvement in spatiotemporal gait parameters under dual-task conditions and on uneven surfaces. This could arise from improved movement confidence and coordination; emotional expression; cognitive skills (planning, multitasking), and; utilisation of external movement cues. A large-scale RCT of this program is warranted.

TRIAL REGISTRATION

A protocol for this study has been registered retrospectively at the Australian New Zealand Clinical Trials Registry. Identifier: ACTRN12618001834246.

Impact of pathological conditions on postural reflex latency and adaptability following unpredictable perturbations: A systematic review and meta-analysis

BACKGROUND

Pathological conditions can impair responses to postural perturbations and increase risk of falls.

RESEARCH QUESTION

To what extent are postural reflexes impaired in people with pathological conditions and can exercise interventions shorten postural reflexes?

METHODS

MEDLINE, EMBASE, Scopus, SportDiscus and Web of Science were systematically searched for articles comparing muscle activation onset latency in people with pathological conditions to healthy controls following unpredictable perturbations including the effect of exercise interventions (registration: CRD42020170861).

RESULTS

Fifty-three articles were included for systematic review. Significant delays in muscle activity onset following perturbations were evident in people with multiple sclerosis (n = 7, mean difference [MD]: 22 ms, 95% confidence interval [CI]: 11, 33), stroke (n = 10, MD: 34 ms, 95% CI: 19, 49), diabetes (n = 2, MD: 19 ms, 95% CI: 10, 27), HIV (n = 3, MD: 9 ms, 95% CI: 4, 14), incomplete spinal cord injury (n = 2, MD: 57 ms, 95% CI: 33, 80) and back and knee pain (n = 7, MD: 12 ms, 95% CI: 6, 18), but not in people with Parkinson's disease (n = 10) or cerebellar dysfunction (n = 4). Following exercise interventions, the paretic limb of stroke survivors (n = 3) displayed significantly faster muscle activation onset latency compared to pre-exercise (MD: -13 ms, 95% CI: -24, -4), with no significant changes in Parkinson's disease (n = 3).

CONCLUSIONS

This systematic review demonstrated that postural reflexes are significantly delayed in people with multiple sclerosis (+22 ms), stroke (+34 ms), diabetes (+19 ms), HIV (+9 ms), incomplete spinal cord injury (+57 ms), back and knee pain (+12 ms); pathological conditions characterized by impaired sensation or neural function. In contrast, timing of postural reflexes was not impaired in people with Parkinson's disease and cerebellar dysfunction, confirming the limited involvement of supraspinal structures. The meta-analysis showed exercise interventions can significantly shorten postural reflex latencies in stroke survivors (-14 ms), but more research is needed to confirm this finding and in people with other pathological conditions.

Including Arts in Rehabilitation Enhances Outcomes in the Psychomotor, Cognitive, and Affective Domains: A Scoping Review

OBJECTIVE

The purpose of this scoping review was to analyze the published literature regarding the use of art in the context of rehabilitation for consideration in physical therapy.

METHODS

The CINAHL, PsycArticles, APA PsycInfo, Art Index, Music Index, Cochrane Reviews, and PubMed electronic databases were accessed. Inclusion and exclusion criteria were established and utilized to determine study eligibility. Study details were extracted from each article by researchers using a systematic format. Summation of journal type, participants, dosing and type of intervention, setting and interventionist, outcome domains, and study results were included.

RESULTS

Out of 1452 studies, 76 were included for extraction. Of these studies, most had outcome measures aligned with the psychomotor and affective domains of learning (n = 66). Very few studies had outcome measures with psychomotor and cognitive domains (n = 2) or psychomotor, affective, and cognitive outcome measures (n = 8). Regarding the arts used, music, dance, or both were used in 77 instances. Fewer studies reported using creative arts therapy, singing, theater, writing, and rhythm (n = 17). Of the 76 studies analyzed, 74 reported a within-group treatment effect.

CONCLUSION

The arts effectively enhance physical therapist practice; therefore, it is recommended that physical therapists continue to seek collaboration with art professionals and explore the use of arts in practice.

IMPACT

Findings demonstrate that combining the arts with physical therapist practice amplifies not only psychomotor but affective and cognitive outcomes as well. The arts have applicability across broad populations (eg, chronic pain, neurologic dysfunction, respiratory conditions). This study supports that physical therapist education and practice should embrace the arts as a collaborative modality to promote enhanced psychomotor, affective, and cognitive outcomes.

Music affects functional brain connectivity and is effective in the treatment of neurological disorders

In a million years, under the pressure of natural selection, hominins have acquired the abilities for vocal learning, music, and language. Music is a relevant human activity, highly effective in enhancing sociality, is a universal experience common to all known human cultures, although it varies in rhythmic and melodic complexity. It has been part of human life since the beginning of our history, or almost, and it strengthens the mother-baby relation even within the mother's womb. Music engages multiple cognitive functions, and promotes attention, concentration, imagination, creativity, elicits memories and emotions, and stimulates imagination, and harmony of movement. It changes the chemistry of the brain, by inducing the release of neurotransmitters and hormones (dopamine, serotonin, and oxytocin) and activates the reward and prosocial systems. In addition, music is also used to develop new therapies necessary to alleviate severe illness, especially neurological disorders, and brain injuries.

Evaluating the effects of dance on motor outcomes, non-motor outcomes, and quality of life in people living with Parkinson's: a feasibility study

BACKGROUND

Community-based dance programs for people living with Parkinson's have grown in popularity over the past two decades. Studies investigating these programs have demonstrated multidimensional benefits in motor, non-motor, and quality of life related outcomes, yet there is a need to focus on the feasibility of larger trials. The primary objective of this study was to assess the feasibility and acceptability of conducting a trial investigating dance and Parkinson's in Northern Ireland. The secondary objectives were to conduct preliminary analyses of the classes' effects and to assess the appropriateness of outcome measures for a randomized controlled trial.

METHODS

Participants were recruited through the community, Parkinson's UK, and university contacts to participate in a 12-week dance intervention inspired by the Dance for PD® model. Pre- and post-intervention, participants completed the following outcomes: MDS-UPDRS III, TUG, DT-TUG, Sensory Organization Test, MoCA, Trail Making Tests A&B, Digit Symbol Substitution Test, Digit Span, PDQ-39, FOG-Q, PHQ-9, FES-I, and an exit questionnaire (post-test only). Data were analyzed using paired samples t tests or Wilcoxon signed ranked test.

RESULTS

Ten people living with Parkinson's participated. Running a larger trial was deemed infeasible in this setting due to recruitment issues; conversely, the dance intervention was accepted by participants with all but one completing the study. Functional mobility (TUG), symptoms of depression (PHQ-9), and bodily discomfort showed improvement. All other outcomes did not. The exit questionnaire revealed that the social aspect of classes was important, and improvements in mood or mental state were cited most frequently as perceived benefits. Outcome measures were feasible, with some changes suggested for future trials.

CONCLUSIONS

This study highlighted the infeasibility of running a larger trial using this design in this setting despite demonstrating the acceptability of implementing a dance program in Northern Ireland for people living with Parkinson's. The results support existing evidence demonstrating that dance may improve functional mobility and symptoms of depression in people living with Parkinson's, though the study design and small sample size prevent the generalizability of results. The findings also support the idea that dancing has the potential to support several aspects of physical, emotional, mental, and social health.

Dance Is an Accessible Physical Activity for People with Parkinson's Disease

OBJECTIVE

To evaluate the outcomes of face-to-face, digital, and virtual modes of dancing for people living with Parkinson's disease (PD).

DESIGN

Systematic review informed by Cochrane and PRIMSA guidelines. Data Sources. Seven electronic databases were searched: AMED, Cochrane, PEDro, CINHAL, PsycINFO, EMBASE, and MEDLINE.

METHODS

Eligible studies were randomised controlled trials (RCT) and other trials with quantitative data. The PEDro scale evaluated risk of bias for RCTs. Joanna Briggs Institute instruments were used to critically appraise non-RCTs. The primary outcome was the feasibility of dance interventions, and the secondary outcomes included gait, balance, quality of life, and disability.

RESULTS

The search yielded 8,327 articles after duplicates were removed and 38 met the inclusion criteria. Seven were at high risk of bias, 20 had moderate risk of bias, and 11 had low risk of bias. There was moderately strong evidence that dance therapy was beneficial for balance, gait, quality of life, and disability. There was good adherence to digital delivery of dance interventions and, for people with PD, online dance was easy to access.

CONCLUSION

Dancing is an accessible form of exercise that can benefit mobility and quality of life in people with PD. The COVID-19 pandemic and this review have drawn attention to the benefits of access to digital modes of physical activity for people living with chronic neurological conditions.

Abnormal center of mass feedback responses during balance: A potential biomarker of falls in Parkinson's disease

Although Parkinson disease (PD) causes profound balance impairments, we know very little about how PD impacts the sensorimotor networks we rely on for automatically maintaining balance control. In young healthy people and animals, muscles are activated in a precise temporal and spatial organization when the center of body mass (CoM) is unexpectedly moved that is largely automatic and determined by feedback of CoM motion. Here, we show that PD alters the sensitivity of the sensorimotor feedback transformation. Importantly, sensorimotor feedback transformations for balance in PD remain temporally precise, but become spatially diffuse by recruiting additional muscle activity in antagonist muscles during balance responses. The abnormal antagonist muscle activity remains precisely time-locked to sensorimotor feedback signals encoding undesirable motion of the body in space. Further, among people with PD, the sensitivity of abnormal antagonist muscle activity to CoM motion varies directly with the number of recent falls. Our work shows that in people with PD, sensorimotor feedback transformations for balance are intact but disinhibited in antagonist muscles, likely contributing to balance deficits and falls.

Rationale and Design of the PAIRED Trial: Partnered Dance Aerobic Exercise as a Neuroprotective, Motor, and Cognitive Intervention in Parkinson's Disease

Parkinson's disease (PD), an intractable condition impairing motor and cognitive function, is imperfectly treated by drugs and surgery. Two priority issues for many people with PD are OFF-time and cognitive impairment. Even under best medical management, three-fourths of people with PD experience “OFF-time” related to medication-related motor fluctuations, which severely impacts both quality of life and cognition. Cognitive deficits are found even in newly diagnosed people with PD and are often intractable. Our data suggest that partnered dance aerobic exercise (PDAE) reduces OFF-time on the Movement Disorders Society Unified Parkinson Disease Rating Scale-IV (MDS-UPDRS-IV) and ameliorates other disease features, which motivate the PAIRED trial. PDAE provides AE during an improvisational, cognitively engaging rehabilitative physical activity. Although exercise benefits motor and cognitive symptoms and may be neuroprotective for PD, studies using robust biomarkers of neuroprotection in humans are rare. We propose to perform a randomized, controlled trial in individuals with diagnosed mild–moderate PD to compare the efficacy of PDAE vs. walking aerobic exercise (WALK) for OFF-time, cognition, and neuroprotection. We will assess neuroprotection with neuromelanin-sensitive MRI (NM-MRI) and iron-sensitive (R2^*) MRI sequences to quantify neuromelanin loss and iron accumulation in substantia nigra pars compacta (SNc). We will use these biomarkers, neuromelanin loss, and iron accumulation, as tools to chart the course of neurodegeneration in patients with PD who have undergone long-term (16 months) intervention. We will randomly assign 102 individuals with mild–moderate PD to 16 months of PDAE or WALK. The 16-month intervention period will consist of Training (3 months of biweekly sessions) and Maintenance (13 months of weekly sessions) phases. We will assess participants at baseline, 3 months (immediately post-Training), and 16 months (immediately post-Maintenance) for OFF-time and behaviorally and physiologically measured cognition. We will acquire NM-MRI and R2^* imaging data at baseline and 16 months to assess neuroprotection. We will (1) examine effects of Training and Maintenance phases of PDAE vs. WALK on OFF-time, (2) compare PDAE vs. WALK at 3 and 16 months on behavioral and functional MRI (fMRI) measures of spatial cognition, and (3) compare PDAE vs. WALK for effects on rates of neurodegeneration.

Argentine tango in the care of Parkinson's disease: A systematic review and analysis of the intervention

OBJECTIVE

To analyse the content of the interventions reported in studies investigating the applicability and efficacy of Argentine tango in participants with Idiopathic Parkinson Disease.

METHODS

Independent reviewers searched databases (PubMed, CINAHL, EMBASE, PsycINFO, and PEDro) from their inception to November 2019. Eligible studies were randomised, controlled and uncontrolled clinical trials, and case reports.

MAIN OUTCOME MEASURE

The Template for Intervention Description and Replication guidelines and checklist were used to assess quality and quantity of the content of Argentine tango interventions' description.

RESULTS

We found 21 papers investigating the applicability and efficacy of Argentine tango in participants with Idiopathic Parkinson Disease. Completeness of the reporting of intervention was satisfying. The intervention is intended to affect a variety of aspects of functioning relevant to individuals with Idiopathic Parkinson Disease. Detailed information on the intervention's procedure and dosing is usually provided. The delivery of the Tango dance program was predominantly extensive; however, the intervention has been provided with various approaches and showed to be very adaptable. Attrition- and adherence- rates described are acceptable. The Adapted Tango dance program is the earliest and most researched modality of tango intervention in participants with Idiopathic Parkinson Disease.

CONCLUSIONS

Argentine tango is appropriately described in the studies investigating the applicability and efficacy of the intervention in participants with Idiopathic Parkinson Disease. However, the reporting could be ameliorated.

The efficacy of dance for improving motor impairments, non-motor symptoms, and quality of life in Parkinson's disease: A systematic review and meta-analysis

Dance may help individuals living with Parkinson's disease (PD) improve motor and non-motor symptoms that impact quality of life (QOL). The primary aim of this systematic review of randomized controlled trials (RCTs) was to evaluate the efficacy of dance in improving motor and non-motor symptoms of PD and QOL. The secondary aims of this review were to evaluate the methodological quality of included studies by assessing risk of bias across nine categories and to inform the direction of future research. Peer-reviewed RCTs that included people living with PD at all disease stages and ages and measured the effects of a dance intervention longer than one day were included. Sixteen RCTs involving 636 participants with mild to moderate PD were eligible for inclusion in the qualitative synthesis and nine in the meta-analysis. Overall, the reviewed evidence demonstrated that dance can improve motor impairments, specifically balance and motor symptom severity in individuals with mild to moderate PD, and that more research is needed to determine its effects on non-motor symptoms and QOL. RCTs that use a mixed-methods approach and include larger sample sizes will be beneficial in fully characterizing effects and in determining which program elements are most important in bringing about positive, clinically meaningful changes in people with PD.

Dance improves symptoms, functional mobility and fine manual dexterity in people with Parkinson disease: a quasi-experimental controlled efficacy study

BACKGROUND

Clinically, individuals diagnosed with Parkinson disease (PD) present several symptoms that impact on their functional independence and quality of life. While there is accumulating evidence supporting dance as an effective symptom management option, few studies have objectively assessed these benefits, particularly related to the Dance for Parkinson's Disease^® (DfPD^®) program.

AIM

The aim of this study was to explore the effects of DfPD^®-based dance classes on disease-related symptoms, fine-manual dexterity and functional mobility in people with PD.

DESIGN

A quasi-experimental controlled efficacy study, with pre and post testing of two parallel groups (dance versus control).

SETTING

Community.

POPULATION

Thirty-three participants with PD allocated to one of two groups: dance group (DG; N.=17; age=65.8±11.7 years) or control group (CG: N.=16; age=67.0±7.7 years). They were cognitively intact (Addenbrooke's Score: DG=93.2±3.6, CG=92.6±4.3) and in early-stage of disease (Hoehn & Yahr: DG=1.6±0.7, CG=1.5±0.8).

METHODS

The DG undertook a one-hour DfPD^®-based class, twice weekly for 12 weeks. The CG had treatment as usual. Both groups were assessed at baseline and after 12 weeks on disease-related symptom severity (MDS-Unified Parkinson Disease Rating Scale: MDS-UPDRS), fine-manual dexterity (Perdue Peg Board), measures of functional mobility (Timed Up & Go: single & dual task, Tinetti, Berg, Mini-BESTest) and self-rated balance and gait questionnaires (Activities Balance Confidence Scale: ABC-S; Gait and Falls: G&F-Q; Freezing of Gait: FOG).

RESULTS

Compared to the CG, there was significantly greater improvement in the DG pre-post change scores on measures of symptom severity MDS-UPDRS, dexterity, six measures of functional mobility, and the ABC-S, G&F-Q, FOG questionnaires.

CONCLUSIONS

DfPD^®-based dance classes improved disease-related symptom severity, fine-manual dexterity, and functional mobility. Feasibility of the approach for a large scale RCT was also confirmed.

CLINICAL REHABILITATION IMPACT

DfPD^® could be an effective supportive therapy for the management of symptoms and functional abilities in PD.

Effects of Dance on Gait, Cognition, and Dual-Tasking in Parkinson's Disease: A Systematic Review and Meta-Analysis

Dance-based interventions have been proposed for the management of Parkinson's disease (PD) symptoms. This review critically appraises and synthesises the research on the effects of dance interventions on gait, cognition and dual-tasking in PD, through a meta-analysis of peer-reviewed literature from seven databases. Eligible studies included people with PD, used a parallel-group or cohort design with a dance-based intervention, reported outcome measures of gait, cognition or dual-tasking, and were published in English up until September 2017. Of the initial 1079 articles, 677 articles were reviewed for eligibility, and 25 articles were retained. Only 12 articles had sufficient common assessment items for meta-analysis. Two independent reviewers extracted the data and assessed the risk of bias of each study using the Cochrane risk-of-bias tool. Based on pre-post change scores, gait speed, Timed Up and Go (TUG) test performance, freezing of gait questionnaire, and six-minute walk test times significantly improved after a dance intervention compared to controls. Global cognition assessed with Montreal Cognitive Assessment, and cognitive dual-tasking measured using dual-task TUG, also exhibited greater improvement in dance groups. There was limited evidence to determine the most effective intensity, frequency, duration of dance interventions or the most beneficial music. Findings must be interpreted cautiously because of the lack of randomised control trials, and the moderate to high risk of bias of studies. However, the results of papers with level-I and level-II.1 evidence suggest that dance may have the potential to ameliorate PD symptoms, particularly gait, global cognition and cognitive dual-tasking.

Perception of whole-body motion during balance perturbations is impaired in Parkinson's disease and is associated with balance impairment

BACKGROUND

In addition to motor deficits, Parkinson's disease (PD) may cause perceptual impairments. The role of perceptual impairments in sensorimotor function is unclear, and has typically been studied in single-joint motions.

RESEARCH QUESTION

We hypothesized that perception of whole-body motion is impaired in PD and contributes to balance impairments. We tested (1) whether directional acuity to whole body perturbations during standing was worse in people with PD compared to neurotypical older adults (NOA), and (2) whether balance ability, as assessed by the MiniBESTest, was associated with poor directional acuity in either group.

METHODS

Participants were exposed to pairs of support-surface translation perturbations in a two-alternative forced choice testing paradigm developed previously in a young healthy population. The first perturbation of each pair that was to be judged by participants was directly backward, and the second perturbation deviated from the left or right from the backward direction by 1°-44°. Participants reported whether the perturbations in each pair were in the "same" or "different" direction. Judgements from 24 to 67 perturbation pairs were used to calculate directional acuity thresholds corresponding to "just-noticeable differences" in perturbation direction. Linear mixed models determined associations between directional thresholds and clinical variables including MDS-UPDRS-III score, age, and MiniBESTest score.

RESULTS

20 PD (64 ± 7 y, 12 male, ≥12 h since last intake of antiparkinsonian medications) and 12 NOA (64 ± 8, 6 male) were assessed. Directional thresholds were higher (worse) among PD participants (17.6 ± 5.9° vs. 12.8 ± 3.3°, P < 0.01). Linear mixed models further showed that higher thresholds were associated with MDS-UPDRS-III score (P < 0.01), and were associated with poorer balance ability among PD participants (P < 0.01), but not among NOA participants (P = 0.40).

SIGNIFICANCE

Perception of whole-body motion is impaired in PD and may contribute to impaired balance and falls.

Dance and Parkinson's: A review and exploration of the role of cognitive representations of action

Parkinson's disease (PD) is a neurodegenerative condition that causes both sensorimotor and non-motor impairments, and there is a clear need for non-medical approaches to improve quality of life. Dance is an increasingly popular activity among people with PD, which demonstrates potential therapeutic benefits. However, findings to date have been inconsistent, and little is known about the mechanisms underlying benefits of dance in PD. In this review, we provide an overview of research into dance for people with PD. The majority of quantitative evidence is in the sensorimotor domain, but cognitive, psychological and social effects have also been reported. We consider the role of cognitive representations of action within dance through observation, imitation and imagery, which may contribute to both sensorimotor and non-motor outcomes for people with PD. Moreover, we discuss how these processes may be enhanced through dance to provide further benefits in everyday life. Finally, we propose avenues for future research to increase understanding of action representation in dance for PD, which has the potential to inform practice and maximize benefits.

The effect of balance training with Tetra-ataxiometric posturography on balance function in patients with parkinsonism

BACKGROUND

Balance impairment is a major clinical concern in patients with parkinsonism. Balance training with tetra-ataxiometric posturography (Tetrax) is known to improve balance function through visual biofeedback effects.

OBJECTIVE

In this study, we evaluated the effects of balance training with Tetrax in patients with parkinsonism.

METHODS

Patients with parkinsonism (idiopathic Parkinson's disease, multiple systemic atrophy, and multiple systemic atrophy) who were able to stand with or without an assistive device were recruited for the study. Twenty patients with parkinsonism were randomly assigned to one of the following two groups: (1) the Tetrax group, in which patients received Tetrax biofeedback balance training for 30 min/day for 2 weeks (10 sessions); and (2) the control group, in which patients received conventional balance training for 30 min/day for 2 weeks (10 sessions). One day before and after training, we measured patients' balance parameters using the Berg balance scale (BBS) and fall index (FI).

RESULTS

The BBS and FI scores of the Tetrax group showed significant improvements after compared to before training. However, the scores in the control group were not significantly changed after vs. before conventional balance training.

CONCLUSIONS

For patients with parkinsonism, Tetrax biofeedback balance training had a positive effect on balance function.

Falls in Synucleinopathies

Parkinson's disease (PD) and other synucleinopathies, namely dementia with Lewy bodies (DLB) and multiple system atrophy (MSA), are common degenerative neurological disorders that share synuclein pathology. Although certain cardinal features of parkinsonism, including bradykinesia and rigidity, respond well to levodopa, axial features, such as gait and balance impairment, are less reliably responsive to dopaminergic therapy and surgical interventions. Consequently, falls are common in PD and other synucleinopathies and are a major contributor toward injury and loss of independence. This underscores the need for appropriate fall risk assessment and implementation of preventative measures in all patients with parkinsonism. The aim of this review is therefore to explore modifiable and non-modifiable risk factors for falls in synucleinopathies. We next review and evaluate the evidence for pharmacological, nonpharmacological, and surgical approaches for fall prevention, and emphasize individualized and multifaceted approaches.

Lower Limb Rigidity Is Associated with Frequent Falls in Parkinson's Disease

BACKGROUND AND OBJECTIVE

The role of muscle rigidity as an etiological factor of falls in Parkinson's disease (PD) is poorly understood. Our objective was to determine whether lower leg rigidity was differentially associated with frequent falls in PD compared to upper limb, neck, and total rigidity measures.

METHODS

We examined the associations between Unified Parkinson's Disease Rating Scale-Part III (motor) rigidity subscores and the history of monthly or more frequent falls in 216 individuals with PD (age, 66 ± 10 years; 36% female; disease duration, 7 ± 5 years) with logistic regression.

RESULTS

A total of 35 individuals were frequent fallers. Significant associations were identified between lower limb rigidity and frequent falls (P = 0.01) after controlling for age, sex, PD duration, total Unified Parkinson's Disease Rating Scale- Part III score, and presence of freezing of gait. No significant associations (P ≥ 0.14) were identified for total, arm, or neck rigidity.

CONCLUSION

Lower limb rigidity is related to frequent falls in people with PD. Further investigation may be warranted into how parkinsonian rigidity could cause falls.

Do sensorimotor perturbations to standing balance elicit an error-related negativity?

Detecting and correcting errors is essential to successful action. Studies on response monitoring have examined scalp ERPs following the commission of motor slips in speeded-response tasks, focusing on a frontocentral negativity (i.e., error-related negativity or ERN). Sensorimotor neurophysiologists investigating cortical monitoring of reactive balance recovery behavior observe a strikingly similar pattern of scalp ERPs following externally imposed postural errors, including a brief frontocentral negativity that has been referred to as the balance N1. We integrate and review relevant literature from these discrepant fields to suggest shared underlying mechanisms and potential benefits of collaboration across fields. Unlike the cognitive tasks leveraged to study the ERN, balance perturbations afford precise experimental control of postural errors to elicit balance N1s that are an order of magnitude larger than the ERN and drive robust and well-characterized adaptation of behavior within an experimental session. Many factors that modulate the ERN, including motivation, perceived consequences, perceptual salience, expectation, development, and aging, are likewise known to modulate the balance N1. We propose that the ERN and balance N1 reflect common neural activity for detecting errors. Collaboration across fields could help clarify the functional significance of the ERN and poorly understood interactions between motor and cognitive impairments.

Antagonist muscle activity during reactive balance responses is elevated in Parkinson's disease and in balance impairment

BACKGROUND

Abnormal antagonist leg muscle activity could indicate increased muscle co-contraction and clarify mechanisms of balance impairments in Parkinson's disease (PD). Prior studies in carefully selected patients showed PD patients demonstrate earlier, longer, and larger antagonist muscle activation during reactive balance responses to perturbations.

RESEARCH QUESTION

Here, we tested whether antagonist leg muscle activity was abnormal in a group of PD patients who were not selected for phenotype and most of whom had volunteered for exercise-based rehabilitation.

METHODS

We compared antagonist activation during reactive balance responses to multidirectional support-surface translation perturbations in 31 patients with mild-moderate PD (age 68±9; H&Y 1-3; UPDRS-III 32±10) and 13 matched individuals (age 65±9). We quantified modulation of muscle activity (i.e., the ability to activate and inhibit muscles appropriately according to the perturbation direction) using modulation indices (MI) derived from minimum and maximum EMG activation levels observed across perturbation directions.

RESULTS

Antagonist leg muscle activity was abnormal in unselected PD patients compared to controls. Linear mixed models identified significant associations between impaired modulation and PD (P<0.05) and PD severity (P<0.01); models assessing the entire sample without referencing PD status identified associations with balance ability (P<0.05), but not age (P = 0.10).

SIGNIFICANCE

Antagonist activity is increased during reactive balance responses in PD patients who are not selected on phenotype and are candidates for exercise-based rehabilitation. This activity may be a mechanism of balance impairment in PD and a potential rehabilitation target or outcome measure.

Music Therapy and Dance as Gait Rehabilitation in Patients With Parkinson Disease: A Review of Evidence

AIM

This review aims to demonstrate the efficiency of music and dance for gait improvement and symptom alleviation in Parkinson disease.

METHODOLOGY

Studies that analyzed sound stimuli and dance in gait improvement in Parkinson disease were searched through PubMed, Scopus, Doaj, MEDLINE, and ScienceDirect databases from November 2017 to April 2018 and repeated in September 2018.

RESULTS AND DISCUSSION

Forty-five studies met the inclusion criteria to synthesize the findings on dance and music performance as a treatment for classical symptoms of Parkinson disease. Five reviews and 40 experimental papers have shown that rhythmic stimulation and dance provide the motor, cognitive, and quality of life benefits for participants with Parkinson disease. Thus, sound stimuli and dance offer satisfactory effects for gait, improving cognitive abilities such as motor control and adjustment and spatial memory. In addition, these new treatment modalities stimulate the elderly population to practice physical exercise, generating well-being and helping self-esteem.

CONCLUSION

Dance and music therapy interventions are noninvasive, simple treatment options, which promote gait and cognition.

Adaptations to Postural Perturbations in Patients With Freezing of Gait

Introduction: Freezing of gait (FOG) is a powerful determinant of falls in Parkinson's disease (PD). Automatic postural reactions serve as a protective strategy to prevent falling after perturbations. However, differences in automatic postural reactions between patients with and without FOG in response to perturbation are at present unclear. Therefore, the present study aimed to compare the response patterns and neuromuscular control between PD patients with and without FOG and healthy controls (HCs) after postural perturbations.

Methods: 28 PD patients (15 FOG+, 13 FOG−) and 22 HCs were included. Participants stood on a moveable platform while random perturbations were imposed. The first anterior platform translation was retained for analysis. Center of pressure (CoP) and center of mass (CoM) trajectories and trunk, knee and ankle angles were compared between the three groups using the Statistical Parametric Mapping technique, allowing to capture changes in time. In addition, muscle activation of lower leg muscles was measured using EMG.

Results: At baseline, FOG+ stood with more trunk flexion than HCs (p = 0.005), a result not found in FOG−. Following a perturbation, FOG+ reacted with increased trunk extension (p = 0.004) in comparison to HCs, a pattern not observed in FOG−. The CoM showed greater backward displacement in FOG− and FOG+ (p = 0.008, p = 0.027). Both FOG+ and FOG− showed increased co-activation of agonist and antagonist muscles compared to HCs (p = 0.010), with no differences between FOG+ and FOG−.

Conclusions: Automatic postural reactions after a sudden perturbation are similar between PD subgroups with and without FOG but different from HCs. Reactive postural control, largely regulated by brain stem centers, seems to be modulated by different mechanisms than those governing freezing of gait. Greater differences in initial stance position, enhanced by joint stiffening, could however underlie maladaptive postural responses and increase susceptibility for balance loss in FOG+ compared to FOG−.

Impaired set shifting is associated with previous falls in individuals with and without Parkinson's disease

BACKGROUND

Individuals with Parkinson's disease (PD) are at increased risk for falls, which lead to substantial morbidity and mortality. Understanding the motor and non-motor impairments associated with falls in PD is critical to informing prevention strategies. In addition to motor symptoms, individuals with PD exhibit non-motor deficits, including impaired set shifting, an aspect of executive function related to cognitive flexibility that can be measured quickly with the Trailmaking Test.

RESEARCH QUESTION

To determine whether impaired set shifting is associated with fall history in people with and without PD.

METHODS

We examined associations between set shifting, PD status, and fall history (≥1 falls in the previous 6 months) in data from PD patients (n = 65) with and without freezing of gait (FOG) and community-dwelling neurologically-normal older adults (NON-PD) (n = 73) who had participated in our rehabilitation studies.

RESULTS

Impaired set shifting was associated with previous falls after controlling for age, sex, overall cognitive function, PD status, FOG, and PD disease duration (OR = 1.29 [1.03-1.60]; P = 0.02). Consistent with literature, PD and FOG were also independently associated with increased fall prevalence (PD OR = 4.15 [95% CI 1.65-10.44], P < 0.01; FOG OR = 3.63 [1.22-10.80], P = 0.02). Although the strongest associations between set shifting and falling were observed among PD without FOG (OR = 2.11) compared to HOA (OR = 1.14) and PD with FOG (OR = 1.46), no statistically-significant differences were observed across groups.

SIGNIFICANCE

Impaired set shifting is associated with previous falls in older adults with and without PD. Set shifting may be useful to include in fall risk assessments, particularly when global cognitive measures are within reference limits.

Utilization of rehabilitation therapy services in Parkinson disease in the United States

OBJECTIVE

To examine rehabilitation therapy utilization for Parkinson disease (PD).

METHODS

We identified 174,643 Medicare beneficiaries with a diagnosis of PD in 2007 and followed them through 2009. The main outcome measures were annual receipt of physical therapy (PT), occupational therapy (OT), or speech therapy (ST).

RESULTS

Outpatient rehabilitation fee-for-service use was low. In 2007, only 14.2% of individuals with PD had claims for PT or OT, and 14.6% for ST. Asian Americans were the highest users of PT/OT (18.4%) and ST (18.4%), followed by Caucasians (PT/OT 14.4%, ST 14.8%). African Americans had the lowest utilization (PT/OT 7.8%, ST 8.2%). Using logistic regression models that accounted for repeated measures, we found that African American patients (adjusted odds ratio [AOR] 0.63 for PT/OT, AOR 0.63 for ST) and Hispanic patients (AOR 0.97 for PT/OT, AOR 0.91 for ST) were less likely to have received therapies compared to Caucasian patients. Patients with PD with at least one neurologist visit per year were 43% more likely to have a claim for PT evaluation as compared to patients without neurologist care (AOR 1.43, 1.30-1.48), and this relationship was similar for OT evaluation, PT/OT treatment, and ST. Geographically, Western states had the greatest use of rehabilitation therapies, but provider supply did not correlate with utilization.

CONCLUSIONS

This claims-based analysis suggests that rehabilitation therapy utilization among older patients with PD in the United States is lower than reported for countries with comparable health care infrastructure. Neurologist care is associated with rehabilitation therapy use; provider supply is not.

Brazilian Samba Protocol for Individuals With Parkinson's Disease: A Clinical Non-Randomized Study

BACKGROUND

In the 10 most populated countries in the world, Parkinson's disease (PD) affects more than 5 million individuals. Despite optimal treatment options already developed for the disease, concomitant involvement of other areas of health care plays an important role in complementing the treatment. From this perspective, dancing can be viewed as a non-drug alternative that can reduce falls by improving some motor skills, such as mobility, balance, gait, and posture, and can also improve the overall quality of life. Brazilian samba promotes improvement in motor and non-motor symptoms in individuals with PD, providing a new treatment option for this population.

OBJECTIVE

The main objective of this quasi-experimental study is to provide a 12-week samba protocol (2x/week) for individuals with PD and to compare its effects with the group without intervention. The hypothesis is that the Brazilian samba protocol will promote improvement in primary (motor) and secondary (non-motor) outcomes in individuals with PD.

METHODS

The sample will be selected at random from individuals diagnosed with PD in the city of Florianopolis (SC, Brazil). Sample size calculation was performed with the G*Power 3.1.9.2 software, with 0.447 effect size, at 5% significance level, power of 0.9, and test and sample loss of 20%. This yielded 60 individuals divided between the intervention and control groups. The questionnaires will be filled out before and after the dance intervention. The data collection for the control group will be held simultaneously to the intervention group. The classes will last for 1 hour, twice a week in the evening for 12 weeks, and all classes will be divided into warm-up, main part, and relaxation. Two-way analysis of variance with repeated measures and Sidak post-hoc comparison test will be used for a comparative analysis of the final results of the control group with the experimental group and of the within-group changes between pre- and postintervention period.

RESULTS

We expect to complete follow-up in September 2017.

CONCLUSIONS

The major inspiration for this study was to encourage the creation of new rehabilitation programs that do not emphasize doctor involvement. This is a unique protocol for PD and we believe it can be an important tool to alleviate the motor and non-motor symptoms of individuals with PD. Dance is a simple activity depending on little equipment and few financial resources, facilitating its implementation and improving the cost-benefit relationship. In addition, activities that have a cultural aspect for the population in question, and which are pleasant, enable the participants to commit long term. This can enhance patient's compliance with the therapy, which is often a problem for many rehabilitation programs.

Increased neuromuscular consistency in gait and balance after partnered, dance-based rehabilitation in Parkinson's disease

Here we examined changes in muscle coordination associated with improved motor performance after partnered, dance-based rehabilitation in individuals with mild to moderate idiopathic Parkinson's disease. Using motor module (a.k.a. muscle synergy) analysis, we identified changes in the modular control of overground walking and standing reactive balance that accompanied clinically meaningful improvements in behavioral measures of balance, gait, and disease symptoms after 3 wk of daily Adapted Tango classes. In contrast to previous studies that revealed a positive association between motor module number and motor performance, none of the six participants in this pilot study increased motor module number despite improvements in behavioral measures of balance and gait performance. Instead, motor modules were more consistently recruited and distinctly organized immediately after rehabilitation, suggesting more reliable motor output. Furthermore, the pool of motor modules shared between walking and reactive balance increased after rehabilitation, suggesting greater generalizability of motor module function across tasks. Our work is the first to show that motor module distinctness, consistency, and generalizability are more sensitive to improvements in gait and balance function after short-term rehabilitation than motor module number. Moreover, as similar differences in motor module distinctness, consistency, and generalizability have been demonstrated previously in healthy young adults with and without long-term motor training, our work suggests commonalities in the structure of muscle coordination associated with differences in motor performance across the spectrum from motor impairment to expertise.NEW & NOTEWORTHY We demonstrate changes in neuromuscular control of gait and balance in individuals with Parkinson's disease after short-term, dance-based rehabilitation. Our work is the first to show that motor module distinctness, consistency, and generalizability across gait and balance are more sensitive than motor module number to improvements in motor performance following short-term rehabilitation. Our results indicate commonalities in muscle coordination improvements associated with motor skill reacquisition due to rehabilitation and motor skill acquisition in healthy individuals.

Curved Walking Rehabilitation with a Rotating Treadmill in Patients with Parkinson's Disease: A Proof of Concept

Training subjects to step-in-place eyes open on a rotating platform while maintaining a fixed body orientation in space [podokinetic stimulation (PKS)] produces a posteffect consisting in inadvertent turning around while stepping-in-place eyes closed [podokinetic after-rotation (PKAR)]. Since the rationale for rehabilitation of curved walking in Parkinson's disease is not fully known, we tested the hypothesis that repeated PKS favors the production of curved walking in these patients, who are uneasy with turning, even when straight walking is little affected. Fifteen patients participated in 10 training sessions distributed in 3 weeks. Both counterclockwise and clockwise PKS were randomly administered in each session. PKS velocity and duration were gradually increased over sessions. The velocity and duration of the following PKAR were assessed. All patients showed PKAR, which increased progressively in peak velocity and duration. In addition, before and at the end of the treatment, all patients walked overground along linear and circular trajectories. Post-training, the velocity of walking bouts increased, more so for the circular than the linear trajectory. Cadence was not affected. This study has shown that parkinsonian patients learn to produce turning while stepping when faced with appropriate training and that this capacity translates into improved overground curved walking.