Digital gait biomarkers in Parkinson's disease: susceptibility/risk, progression, response to exercise, and prognosis

This narrative review examines the utility of gait digital biomarkers in Parkinson's disease (PD) research and clinical trials across four contexts: disease susceptibility/risk, disease progression, response to exercise, and fall prediction. The review of the literature to date suggests that upper body characteristics of gait (e.g., arm swing, trunk motion) may indicate susceptibility/risk of PD, while pace aspects (e.g., gait speed, stride length) are informative for tracking disease progression, exercise response, and fall likelihood. Dynamic stability aspects (e.g., trunk regularity, double-support time) worsen with disease progression but can improve with exercise. Gait variability emerges as a sensitive biomarker across all 4 contexts but with low specificity. The lack of standardized gait testing protocols and the lack of a minimum set of quantified digital gait biomarkers limit data harmonization across studies. Future studies, using a commonly agreed upon protocol, could be used to demonstrate the utility of specific gait biomarkers for clinical practice.

The impact of aerobic exercise dose based on ACSM recommendations on patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

Background

To explore the effects of different dose of aerobic exercise on motor function, balance, mobility, and quality of life in Parkinson's disease patients, aiming to provide insights into determining the optimal aerobic exercise dose for treating PD.

Methods

Searching was conducted in four databases: PubMed, Embase, Web of Science, and Cochrane. The dose of aerobic exercise intervention was evaluated based on the recommendations of the American College of Sports Medicine regarding the development and maintenance of cardiorespiratory health, muscle strength, and functional mobility in patients with PD. The exercise intervention dose of the included studies were first classified into high ACSM compliance and low ACSM compliance based on meeting 4/6 of the ACSM recommendations. The reliability of the results was then validated using the criterion of meeting 5/6 of the ACSM recommendations. Comparisons of the effects of aerobic exercise dose on Motor function, Balance, Mobility, and QOL in PD patients using standardized mean difference with 95% confidence intervals.

Results

When using the 4/6 ACSM compliance criterion, 17 studies were categorized as high ACSM compliance and 12 as low ACSM compliance. The SMD ratios for high versus low ACSM compliance were: UPDRS-III (-0.79: -0.18), BBS (0.60: 0.05), TUG (-0.60: -0.60), and QOL (-1.05: -0.15). When using the 5/6 ACSM compliance criterion, 11 studies were categorized as high ACSM compliance and 19 as low ACSM compliance. The SMD ratios for high versus low ACSM compliance were: UPDRS-III (-0.95: -0.38), BBS (0.48: 0.37), TUG (-0.71: -0.55), and QOL (-0.7: 0.04).

Conclusion

This study provides preliminary support for the potential of aerobic exercise to improve certain clinical symptoms in patients with PD. Furthermore, the results indicate that compliance to higher doses of aerobic exercise, as per ACSM standards, may contribute to improvements in motor function, balance, mobility, and quality of life for patients with PD. However, due to the heterogeneity in the studies and the influence of factors that have not yet been fully explored, these conclusions should be interpreted with caution. More high-quality randomized controlled trials are needed in the future to further verify and clarify the effects of aerobic exercise.

Systematic review registration

https://www.crd.york.ac.uk/prospero, identifier PROSPERO: CRD42024517548.

Parkinson's Critical Heart Rate Test: Applying the Critical Power Model for People with Parkinson's Disease

Aerobic exercise with the correct intensity can attenuate motor and non-motor symptoms of Parkinson's disease (PD) and improve the quality of life. However, a specific, validated, non-invasive, and outside the laboratory protocol that assesses physiological variables to prescribe optimal aerobic exercise intensity for people with PD is nonexistent. Therefore, this study aimed to propose a protocol, the Parkinson's critical heart rate test (Parkinson-CHR test), to determine the critical heart rate (CHR) in individuals with PD and verify its validity, reliability, and sensitivity. Fifteen people with idiopathic PD, who were able to practice exercises, were recruited to participate in the study (71.1 ± 6.6 years). The study consisted of two experiments: i) the first one aimed to assess the validity and reliability of the protocol, with participants performing the test twice at a one-week interval; ii) the second experiment aimed to investigate the protocol sensitivity, with individuals being evaluated before and after an 8-week training program according to Parkinson-CHR intensity. In experiment 1, no differences between test and retest were observed in the time to cover the distances (400, 800 and 1200 m), the total heart rate, the critical heart rate, and critical speed (p > 0.05). In experiment 2, there was a reduction in time to cover 400 and 800 m as well as in the total heart rate for all distances after the 8-week training program. The Parkinson-CHR test is a reliable, reproducible, inexpensive, and non-invasive protocol to assess, prescribe, and monitor aerobic exercise intensity in people with PD.

The effects of exercise dose on patients with Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The effects of different exercise doses on motor function, balance, mobility, and quality of life (QOL) in patients with Parkinson's disease (PD) were evaluated.

METHOD

The exercise intervention dose was evaluated based on the recommendations of the American College of Sports Medicine (ACSM) for developing and maintaining cardiorespiratory health, muscle strength, and physical function for PD patients and classified into high ACSM compliance and low or uncertain ACSM compliance. The impact of ACSM compliance on Unified Parkinson's Disease Rating Scale, Part III (UPDRS-III), Berg Balance Scale (BBS), Timed Up and Go (TUG), and 39-item Parkinson's Disease Questionnaire (PDQ-39) in patients with PD was compared using the standardized mean difference (SMD) along with the corresponding 95% confidence interval (95% CI).

RESULTS

A total of 26 articles were included, comprising 32 studies. Twenty-one studies were classified as high ACSM compliance, and 11 studies were classified as low or uncertain ACSM compliance. For the four outcome measures, the SMD ratio of exercise interventions with high ACSM compliance to those with low or uncertain ACSM compliance was as follows: UPDRS-III (- 0.74: - 0.17), TUG (- 0.62: - 0.17), PDQ-39 (- 0.58: - 0.31), and BBS (0.51: 0.52).

CONCLUSION

The results suggest that compared with exercise interventions with low or uncertain ACSM compliance, exercise interventions with high ACSM compliance had a more significant improvement effect on motor function, mobility, and QOL in PD patients. However, the effect on balance was not as pronounced, and further research is needed to validate these findings.

Effect of Physiotherapy Interventions on Motor Symptoms in People With Parkinson's Disease: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effectiveness of different types of physiotherapy interventions in people with Parkinson's disease (PD).

DESIGN

Systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

Five databases (PubMed, Embase, Cochrane Library, CINAHL and Web of Science Core Collection) were searched for relevant RCTs published from database inception to July 14, 2022. Reviewers independently screened the literature, extracted data, and assessed the literature quality according to the Cochrane Collaboration Risk of Bias Tool and PEDro Scale. This meta-analysis was conducted using RevMan 5.4.1 and reported in compliance with the PRISMA statement.

RESULTS

Forty-two RCTs with 2,530 participants were included. Across all types of physiotherapy, strength training, mind-body exercise, aerobic exercise, and non-invasive brain stimulation (NiBS) were effective in improving motor symptoms as measured by the (Movement Disorders Society-) Unified PD Scale, whereas balance and gait training (BGT) and acupuncture were not. The pooled results showed that the change in mind-body exercise (MD = -5.36, 95% CI [-7.97 to -2.74], p < .01, I2 = 68%) and NiBS (MD = -4.59, 95% CI [-8.59 to -0.59], p = .02, I2 = 78%) reached clinical threshold, indicating clinically meaningful improvements. Considering the effectiveness of the interventions on motor symptoms, balance, gait and functional mobility, mind-body exercise was recommended the most.

CONCLUSIONS

Exercise appears to be a better form of physiotherapy than NiBS and acupuncture for improving motor function. Mind-body exercise showed beneficial effects on motor symptoms, balance, gait and functional mobility in people with PD, and is worthy of being promoted.

A retrospective evaluation of the Brain and Body Fitness Studio service on functional capacity and quality of life in people with neurological disorders

Background

People with neurological disorders (ND) are less physically active than the general population due to physical, sensory, and/or cognitive impairments. These individuals often feel intimidated to join mainstream health and wellness centers due to lack of specialized support for people with ND. The Brain and Body Fitness Studio (BBFS) is one of the first Accredited Exercise Physiologist-led interprofessional services in Adelaide South Australia to provide individualized evidence-based multimodal exercise prescription and social support for this population. This comprehensive retrospective study evaluated the impact of BBFS on functional capacity (FC) determined as the 6-min walk distance (6 MWD) achieved during a 6-min walk test (6 MWT), of its members with ND.

Methods

Sixty-two BBFS members (age, 66 ± 10 years; 60% male) with ND (85% Parkinson's Disease; average time since diagnosis, 4 years [IQR, 2 to 12 years]) and complete pre- and post-6-month clinical assessment of the primary outcome of the study, the 6 MWD, were included in this retrospective analysis. A series of sub-analyses were also performed to investigate the effects of adherence to the recommended prescription of at least twice a week in the program (≥80 vs. < 80% adherence), and disease stage (time since diagnosis; ≥6 vs. < 6 years) on FC.

Results

Although there was no statistically significant change in 6 MWD from pre- to post-6-month BBFS program (+15 ± 90 m, p = 0.19), a clinically meaningful improvement of >14 m was evident. Improvement in 6 MWD was significantly greater in members who attended at least 80% of the recommended visits (≥80% visits, +37 ± 58 m; ≤ 80% visits,-1 ± 105 m, p = 0.046). We also found a 6 MWD improvement from pre- to post-6 months in those in the early years of their ND (< 6 years since diagnosis, +39 ± 76 m), but not in those in the later years of their ND (≥6 years since diagnosis, -36 ± 123 m, between group difference, p = 0.029).

Conclusion

A clinically meaningful 6 MWD improvement may be elicited by services provided by BBFS in people with ND. Overall, the benefits appear to be more evident in members who attended the BBFS for at least 80% of the recommended visits and those who were in the early stage of their ND diagnosis.

A systematic review and meta-analysis on effects of aerobic exercise in people with Parkinson's disease

Previous studies have shown that aerobic exercise is an effective way to improve symptoms of Parkinson's disease (PD). The aim of this study [PROSPERO CRD42022340730] was to explore the effects of aerobic exercises on balance, gait, motor function, and quality of life in PD patients. Searches were performed in PubMed, Web of Science, and EBSCO electronic databases. The Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. From 1287 search records initially identified, 20 studies were considered eligible for systematic review and meta-analysis. There was a significant effect of aerobic exercise on improving timed up and go test [standardized mean difference (SMD), -0.41 (95% CI, -0.61 to -0.22), p < 0.00001], Berg Balance Scale [0.99 (95% CI, 0.76 to 1.23), p < 0.00001], stride/step length [0.32 (95% CI, 0.03 to 0.61), p = 0.03], gait velocity [0.49 (95% CI, 0.20 to 0.78), p = 0.0009], Unified Parkinson's Disease Rating Scale Part-III [-0.40 (95% CI, -0.55 to -0.24), p < 0.00001], and 6-minute walking test [0.35 (95% CI, 0.13 to 0.56), p = 0.002] in people with PD, but not in step cadence [-0.08 (95% CI, -0.43 to 0.27), p = 0.65] and Parkinson's Disease Questionnaire-39 [-0.113 (95% CI, -0.39 to 0.13), p = 0.32]. Aerobic exercise had beneficial effects in improving balance, gait (velocity and stride/step length), and motor function in PD patients. However, aerobic exercise had no significant associations with the step cadence and quality of life in PD patients.

Assessing the Effect of 12 Weeks of Pilates and Aquatic Exercise on Muscle Strength and Range of Motion in Patients with Mild to Moderate Parkinson’s Disease

Background: Parkinson's disease is a chronic, progressive and degenerative disorder of the central nervous system with four main symptoms of bradykinesia, tremor, muscular rigidity, and postural instability. Objectives: The effect of 12 weeks of Pilates and aquatic exercise on muscle strength and range of motion (ROM) in male patients with Parkinson's disease was assessed in this article. Methods: In this quasi-experimental study, 25 male patients reporting to Al-Zahra Hospital, Isfahan, were selected randomly and grouped in Pilates (n = 7), Aquatic exercise (n = 10), and Control (n = 8). The experimental groups received 1-hour sessions of training three times a week for 12 weeks. Muscle strength and ROM of each patient was measured through the Biodex Isokinetic System 3 before entering the study and after the final assigned session. Results: Pilates and Aquatic exercise groups had a significant improvement in ROM, while no significant difference was observed in the control group. Muscle strength and ROM increased significantly in the experimental groups compared to the control group (P < 0.05). The effect of Pilates on muscle strength was not significant (P < 0.05). Conclusions: Non-pharmacological modalities could be contributive in the patients with Parkinson's disease recovery and lead to significant improvements in their physiological parameters of muscle strength and ROM. Next to the pharmacological treatments, patients could benefit from inexpensive and readily available options like Pilates and aquatic exercises to alleviate the disease symptoms. Further studies should be run to reveal the aforementioned and plausible benefits of these complementary activities.

Training in varying environmental contexts facilitates transfer of improved gait performance to new contexts for individuals with Parkinson's disease - a randomized controlled trial

OBJECTIVE

To investigate whether varying practice context during gait training could reduce context-dependency and facilitate transfer of improved gait performance to a new context.

DESIGN

A single-blind, parallel-group randomized controlled trial.

SETTING

Medical university rehabilitation settings.

PARTICIPANTS

Forty-nine participants with PD were recruited and randomized into the constant (CONS) or varied (VARI) context group.

INTERVENTIONS

All participants received 12 sessions of treadmill and over-ground gait training. The CONS group was trained in a constant environmental context throughout the study, while the VARI group received training in 2 different contexts in an alternating order.

MAIN OUTCOME MEASURES

The primary outcome was gait performance, including velocity, cadence, and stride length. The participants were assessed in the original training context as well as in a novel context at post-test to determine the influence of changed environmental context on gait performance.

RESULTS

While both groups improved significantly after training, the CONS group showed greater improvement in stride length than the VARI group when assessed in the original practice context. However, the CONS group showed a decreased velocity and stride length in the novel context, while the VARI group maintained their performance.

CONCLUSIONS

Varying practice context could facilitate transfer of improved gait performance to a novel context.

Effect of Treadmill Training Interventions on Spatiotemporal Gait Parameters in Older Adults with Neurological Disorders: Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective: Treadmill interventions have been shown to promote ‘normal’ walking patterns, as they facilitate the proper movement and timing of the lower limbs. However, prior reviews have not examined which intervention provides the most effective treatment of specific gait impairments in neurological populations. The objective of this systematic review was to review and quantify the changes in gait after treadmill interventions in adults with neurological disorders. Data Sources: A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (January 2000−December 2021). We performed the search algorithm including all possible combinations of keywords. Full-text articles were examined further using forward/backward search methods. Study Selection: Studies were thoroughly screened using the following inclusion criteria: study design: Randomized Controlled Trial (RCT); adults ≥55 years old with a neurological disorder; treadmill intervention; spatiotemporal gait characteristics; and language: English. Data Extraction: A standardized data extraction form was used to collect the following methodological outcome variables from each of the included studies: author, year, population, age, sample size, and spatiotemporal gait parameters including stride length, stride time, step length, step width, step time, stance time, swing time, single support time, double support time, or cadence. Data Synthesis: We found a total of 32 studies to be included in our systematic review through keyword search, out of which 19 studies included adults with stroke and 13 studies included adults with PD. We included 22 out of 32 studies in our meta-analysis that examined gait in adults with neurological disorders, which only yielded studies including Parkinson’s disease (PD) and stroke patients. A meta-analysis was performed among trials presenting with similar characteristics, including study population and outcome measure. If heterogeneity was >50% (denoted by I2), random plot analysis was used, otherwise, a fixed plot analysis was performed. All analyses used effect sizes and standard errors and a p < 0.05 threshold was considered statistically significant (denoted by *). Overall, the effect of treadmill intervention on cadence (z = 6.24 *, I2 = 11.5%) and step length (z = 2.25 *, I2 = 74.3%) in adults with stroke was significant. We also found a significant effect of treadmill intervention on paretic step length (z = 2.34 *, I2 = 0%) and stride length (z = 6.09 *, I2 = 45.5%). For the active control group, including adults with PD, we found that overground physical therapy training had the largest effect on step width (z = −3.75 *, I2 = 0%). Additionally, for PD adults in treadmill intervention studies, we found the largest significant effect was on step length (z = 2.73 *, I2 = 74.2%) and stride length (z = −2.54 *, I2 = 96.8%). Conclusion: Treadmill intervention with sensory stimulation and body weight support treadmill training were shown to have the largest effect on step length in adults with PD and stroke.

Effects of Treadmill Exercise on Neural Mitochondrial Functions in Parkinson's Disease: A Systematic Review of Animal Studies

This systematic review sought to determine the effects of treadmill exercise on the neural mitochondrial respiratory deficiency and neural mitochondrial quality-control dysregulation in Parkinson's disease. PubMed, Web of Science, and EMBASE databases were searched through March 2020. The English-published animal studies that mentioned the effects of treadmill exercise on neural mitochondria in Parkinson's disease were included. The CAMARADES checklist was used to assess the methodological quality of the studies. Ten controlled trials were included (median CAMARADES score = 5.7/10) with various treadmill exercise durations (1-18 weeks). Seven studies analyzed the neural mitochondrial respiration, showing that treadmill training attenuated complex I deficits, cytochrome c release, ATP depletion, and complexes II-V abnormalities in Parkinson's disease. Nine studies analyzed the neural mitochondrial quality-control, reporting that treadmill exercise improved mitochondrial biogenesis, mitochondrial fusion, and mitophagy in Parkinson's disease. The review findings supported the hypothesis that treadmill training could attenuate both neural mitochondrial respiratory deficiency and neural mitochondrial quality-control dysregulation in Parkinson's disease, suggesting that treadmill training might slow down the progression of Parkinson's disease.

Effect of a Training Protocol on Movement Function in Men with Cerebrovascular Accident

: Cerebrovascular accident (CVA) refers to any kind of damage caused by direct or indirect damage to the brain and its related elements. It is estimated that about 60% of brain injury victims have a permanent disorder. The consequences of CVA include reduced movement speed, weakness, functional impairment, reduced power, and balance. The purpose of this study was to investigate the effect of a 12-week selected training protocol on motor function following brain injury. In a semi-experimental study, 30 male subjects with a mean and standard deviation of 52.2 ± 5.4 years, weight 173.2 ± 4.2 kg, and height of 78.8 ± 5.3 cm were selected purposefully and accessible with inclusion and exclusion criteria. The participants were randomly divided into experimental (n = 15) and control groups (n = 15). In order to evaluate the physical-motor performance, 10-meter walking tests, get up and go tests, and climbing stairs tests were used. The training program lasted for 12 weeks, three sessions per week, and each session for 30 - 60 minutes. Data were analyzed by independent t-test and dependent t-test using SPSS-21 software at P ≤ 0.05 level. Based on dependent t-test and covariance test, there were significant differences in all three components of motor function (10 m walk time tests, get up and go test, and stair climbing test), there was a significant increase after training in men with CVA (P = 0.00). From the findings of this study, it can be concluded that the special exercises of the present study have a positive effect on motor function parameters of male patients with CVA, so it can be recommended as one of the most important rehabilitation strategies for these patients.

Cardiovascular, perceived exertion and affective responses during aerobic exercise performed with imposed and a self-selected intensity in patients with Parkinson's disease

BACKGROUND

Exercise with self-selected intensity (SSI) has emerged as a new strategy for exercise prescription aiming to increase exercise adherence in Parkinson's disease (PD).

OBJECTIVE

We compared the cardiovascular, perceived exertion and affective responses during traditional aerobic exercise and with SSI in PD.

METHODS

Twenty patients with PD performed two aerobic exercise sessions in random order with an interval of at least 72 h between them: Traditional session (cycle ergometer, 25 min, 50 rpm) with imposed intensity (II) (60-80% maximum heart rate [HR]) and SSI: (cycle ergometer, 25 min, 50 rpm) with SSI. The HR (Polar V800 monitor), systolic blood pressure (auscultatory method), rating of perceived exertion (Borg scale 6-20) and affective responses (feeling scale) were assessed during the exercise at 8th and 18th minute. The Generalized Estimating Equation Model was used for comparison between both sessions (P < 0.05).

RESULTS

The exercise intensity was not significantly different between both exercise sessions (8th minute: II -76.3±1.0 vs. SSI -76.5±1.3 % of maximal HR; 18th minute: II -78.9±0.9 vs. SSI -79.1±1.3 % of maximal HR, p = 0.93). Blood pressure, perceived exertion and affective responses were also not significantly different between both sessions (P > 0.05).

CONCLUSIONS

Cardiovascular and psychophysiological responses were not different during aerobic exercise performed with II and with SSI in patients with PD.

Effect of aerobic exercise on functional capacity and quality of life in individuals with Parkinson's disease: A systematic review of randomized controlled trials

OBJECTIVES

To investigate the effect of aerobic exercise (AE) on functional capacity and quality of life in individuals with Parkinson's disease (PD) in the mild to moderate stages.

DATA SOURCES

Medline, Embase, Web of Science, The Cochrane Library, Lilacs and PEDro were searched from inception until January 2021 using the MeSH terms.

STUDY SELECTION

Studies conducted in individuals with PD involving AE compared to a control group were included.

DATA EXTRACTION

Characteristics of the studies were independently extracted by two reviewers. The PEDro scale was used to assess the methodological quality, and the level of evidence was analyzed and synthesized using the GRADE approach.

DATA SYNTHESIS

Of the ten studies, 411 individuals with PD were included. The level of synthesized evidence for cardiorespiratory function was low and without effect, and very low and without effect. For gait was very low and with effect for speed and stride length and without effect for cadence. For mobility was very low and with effect. For muscle strength was very low and with effect for the lower limbs as well as without effect for the upper limbs. For postural balance was very low and without effect. For quality of life was low and without effect.

CONCLUSION

Aerobic exercise was capable of promoting improvements in gait (walking speed and stride length), mobility, and lower limb muscle strength in individuals with PD in the mild to moderate stages. No significant improvement in quality of life was found due to the practice of AE.

Do All Resistance Exercise Protocols Improve the Functional Parameters of the Elderly? A Review Study

Context: Aging has been associated with negative changes in the neuromuscular system, significantly impairing the performance of daily life activities. A number of studies have validated functional tests (e.g. timed-up-and-go, gait speed) for the assessment of daily activity performance in the elderly. Thus, it is critical to understand the role of exercise training in this context. The practice of resistance training (RT) has been found to promote muscle strength in the elderly; however, we cannot safely state that any of these resistance exercise protocols would lead to improved performance of functional parameters (e.g. timed-up-and-go, gait speed, getting out of a chair) of this population. To assess the effects of RT on functional parameters of the elderly and to undertake a detailed assessment of the exercise protocols surveyed. Methods: PubMed, Cochrane CENTRAL, and PEDro databases were used to search the literature. A total of 917 articles were initially selected, of which 10 peer-reviewed articles met the search criteria. Results: In the included studies, the positive effects of RT on the functional parameters of the elderly were observed. The training protocols presented the following characteristics: duration of 12 – 16 - 24 - 36 - 60 - 72 sec and 96 sessions; frequency of 1 - 3 sessions per week; training volume of 2 - 5 sets of 4 - 15 repetitions; 40 - 60 - 90 - 120 - 180 sec rest interval between sets; 40 - 60 - 90 - 120 - 180 sec rest interval between exercises; 24 - 48 - 72 hour rest interval between sessions; 40 - 85% intensity of one maximum repetition; isotonic contractions, contraction velocity (as fast as possible-1 - 2 - 3 seconds to concentric and 2 - 3 seconds to eccentric phases). Conclusions: Although the benefits of RT were observed, it was not possible to determine that any of these resistance exercise protocols would lead to improved performance of functional parameters (e.g. timed-up-and-go, gait speed, getting out of a chair) of this population, given the limitations we found in the research papers reviewed.