Does Nordic Walking restore the temporal organization of gait variability in Parkinson's disease?

Nordic walking and arm swing asymmetry in people with Parkinson's disease: protocol for a randomised clinical trial

People with Parkinson's disease (PD) face disruptions in arm swing (AS) motion during walking, including a reduction in amplitude and an increase in asymmetry. Both conditions are detrimental to gait performance. Nordic walking (NW) is a walking modality that uses poles and can positively affect the parameters of AS. This study aims to compare an NW with a free walking (FW) protocol and investigate its effects on AS asymmetry, AS amplitude and gait parameters in people with PD. Twenty-eight people with PD, stages 1-3 on the Hoehn and Yahr Scale, will be randomly assigned to the NW training group (n=14) or the FW training group (n=14). The primary outcomes are amplitude asymmetry of AS (%) and AS amplitude (deg). We will also analyse temporospatial measurements during walking, functional mobility and quality of life. Blinded researchers will conduct evaluations at baseline (T0), postintervention (T1) and at 1 month follow-up (T2). Participants will complete 24 supervised NW or FW training sessions for 12 weeks. This is the first study to address the effects of NW on the asymmetry of AS, AS amplitude and its influence on gait parameters. We hypothesise that an NW programme in PD will reduce the asymmetry and increase the AS amplitude during gait to a greater extent than FW. The results of this study may provide new evidence to understand the effects of NW on gait in people with PD. The study was registered in ClinicalTrial.gov (NCT06342271).

Carpets with visual cues can improve gait in Parkinson's disease patients: may be independent of executive function

BACKGROUND

Gait impairment is common in Parkinson's disease (PD) patients, which greatly reduces their quality of life. Executive dysfunction is associated with gait impairment. Compensatory strategies, including visual cues, have been shown to be effective in improving PD gait. In this study, we aimed to understand whether carpets with visual cues could improve PD gait, and how the improvement varies across patients with different executive function state.

METHODS

We designed carpets with chessboard and stripe cues. A total of 65 Chinese PD patients were recruited. Movement Disorder Society Unified Parkinson's Disease Rating Scale, L-dopa equivalent daily dosage, Hoehn & Yahr stage, Frontal Assessment Battery, Mini Mental State Examination Scale, Hamilton Anxiety Scale, and Hamilton Depression Scale were evaluated. Gait parameters including stride length, gait speed and fall risk were recorded by a wearable electronic device.

RESULTS

The stride length and gait speed were significantly improved and the fall risk was significantly mitigated when PD patients walked on carpets with chessboard and stripe patterns. Further analysis showed the amelioration of gait parameters was independent of executive dysfunction.

CONCLUSIONS

Our study demonstrates that carpets with visual cues can improve the gait of PD patients even in those with mild executive dysfunction.

Nordic walking training in persons with Parkinson's disease: Individualized prescription-A case series

INTRODUCTION

Physical therapy interventions for patients with Parkinson's disease prioritize task-specific exercise to address gait and motor dysfunction. Nordic walking (NW) is a moderate intensity exercise promoting walking speed and rhythm. This case series describes the application of customized NW training in individuals with varied severity of Parkinson's gait dysfunction and the outcomes specific to gait, motor and non-motor symptoms; and NW engagement and retention in the follow-up phase.

CASE DESCRIPTION

Three individuals with idiopathic PD (two males and one female; ages 59-69; Hoehn & Yahr stages II-III) participated. Supervised NW training phase included 15 one-hour sessions over 6-weeks, individually progressed for each participant. During the 3-month follow-up phase independent NW exercise was prescribed 3 times a week. Primary outcome measures examined gait function and impairment-based measures assessed Parkinson's motor and nonmotor symptoms.

OUTCOMES

Participants improved in: 10-Meter walk-fast speed (0.13, 0.18, 0.15 m/s; respectively); 6-Minute Walk distance (137.5, 56.4, 129.4 m, respectively); Unified Parkinson's Disease Rating Scale-Motor Score (-6, -7, -14, respectively); and all Timed-Up-Go subtests. Participant 2 had 44.4% decline in freezing episodes and reduced fall rate. Participants' gains were retained at the 3-month follow-up.

DISCUSSION

This case series suggests that NW has therapeutic benefits for three individuals with varied Parkinson's gait dysfunction. Independent NW exercise was sustained post-training and motor and gait function gains were retained.

Spectral parameters of gait differentiate diabetic patients from healthy individuals

BACKGROUND

Diabetes mellitus (DM) is a clinical condition that affects gait performance and control in millions of individuals worldwide. Contrary to basic spatiotemporal parameters, gait-based spectral analysis may provide useful insights into gait neuromotor control. Hence, this study was set to investigate the spectral content of gait at the preferred speed in patients with DM.

METHODS

Total 1117 individuals [658 DM and 649 healthy adults (HA)] performed a 10 m walk while wearing an inertial measurement unit over the fourth lumbar vertebra. Mann-Whitney-U test was used for between-group gait parameters comparisons.

RESULTS

DM group had a slower step time (1.2%, p < 0.05) and gait speed (2.4%, p < 0.05) than HA. Additionally, DM individuals showed reduced dominant frequency (DM:0.24 Hz vs HA:0.25 Hz on average, p < 0.05). Increased antero-posterior and vertical dominant frequency width (DM:1.73 Hz vs HA:1.76 Hz on average, p < 0.05) and medio-lateral relative power spectral density at the dominant frequency (DM:6.19% vs HA:5.96%, p < 0.05).

CONCLUSIONS

It was demonstrated for the first time that the gait spectral content, not only corroborates spatiotemporal characteristics, but also provides further insight into their neuromotor control deficits in diabetic patients. Ultimately, this type of analysis in the diabetic population can help guide the therapeutic interventions to prevent diabetic foot.

Effects of nordic walking exercise on gait, motor/non-motor symptoms, and serum brain-derived neurotrophic factor in individuals with Parkinson's disease

Objective

The primary purpose of this study was to investigate the immediate and long-term effects of Nordic Walking (NW) exercise on walking function, motor/non-motor Parkinson's Disease (PD) symptoms, and serum brain-derived neurotrophic factor (BDNF) in persons with idiopathic PD.

Methods

Twelve community-dwelling participants with mild to moderate idiopathic PD and varied degrees of gait dysfunction were recruited for this prospective, repeated measures design that examined clinical measures and BDNF levels at baseline (T0), post-intervention (T1) and 3-month follow-up (T2). Participants engaged in 6 weeks of supervised NW exercise training with individualized instruction, followed by 14 weeks of independent NW exercise with remote coaching. Outcome measurements included daily step counts, 6-Minute Walk Test (6-MinWT), 10-Meter Walk Test (10MWT), spatiotemporalparameters, Timed Up and Go Test (TUG), dual-task TUG, Revised-Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Revised-Freezing of Gait Questionnaire, MDS-Nonmotor Symptom scale (NMS), Parkinson's Fatigue Scale, and serum BDNF levels. The Friedman test with post hoc Wilcoxon sign-ranked pairwise comparisons were used to compare baseline to T1, baseline to T2, and T1 to T2 timepoints with a Benjamini-Hockberg correction applied.

Results

Statistically significant improvements found post-training and retained at 3-month follow-up included 6-MinWT, daily step count, 10mWT, MDS-UPDRS, and TUG with effect sizes of 0.57 to 1.03. Serum BDNF at T2 was significantly greater than T0 and T1. Although no statistically significant improvements were observed in the MDS-NMS, 9 of 12 participants had improved non-motor symptoms. There was good adherence, sustained independent exercise engagement, and no adverse events over the 5-month study duration.

Conclusions

This study demonstrated that NW exercise was a safe, feasible, and sustainable mode of aerobic exercise for this sample of participants with varied Parkinson's disease duration and severity. Following an individualized and progressive NW training intervention, significant improvements in walking function, daily activity level, and motor function were observed. Following the supervised NW training phase, independent three-month engagement in NW exercise was sustained with long-term retention of these clinical improvements and an increase in serum BDNF levels over this five-month NW exercise trial.

Impact

Nordic walking exercise may be a safe, feasible and sustainable mode of independent exercise for improving daily ambulatory activity, gait and motor function, and serum BDNF in individuals with mild to moderate PD with varied gait abilities.

Clinical Trials Registry ID

20-101-H.

The Proper Diet and Regular Physical Activity Slow Down the Development of Parkinson Disease

From year to year, we know more about neurodegeneration and Parkinson’s disease (PD). A positive influence of various types of physical activity is more often described in the context of neuroprotection and prevention as well as the form of rehabilitation in Parkinson’s patients. Moreover, when we look at supplementation, clinical nutrition and dietetics, we will see that balancing consumed products and supplementing the vitamins or minerals is necessary. Considering the biochemical pathways in skeletal muscle, we may see that many researchers desire to identify molecular mediators that have an impact through exercise and balanced diet on human health or development of the neurodegenerative disease. Therefore, it is mandatory to study the potential mechanism(s) related to diet and factors resulted from physical activity as molecular mediators, which play a therapeutic role in PD. This review summarizes the available literature on mechanisms and specific pathways involved in diet-exercise relationship and discusses how therapy, including appropriate exercises and diet that influence molecular mediators, may significantly slow down the progress of neurodegenerative processes. We suggest that a proper diet combined with physical activity will be a good solution for psycho-muscle BALANCE not only in PD but also in other neurodegenerative diseases.

Step Length Is a Promising Progression Marker in Parkinson's Disease

Current research on Parkinson’s disease (PD) is increasingly concerned with the identification of objective and specific markers to make reliable statements about the effect of therapy and disease progression. Parameters from inertial measurement units (IMUs) are objective and accurate, and thus an interesting option to be included in the regular assessment of these patients. In this study, 68 patients with PD (PwP) in Hoehn and Yahr (H&Y) stages 1–4 were assessed with two gait tasks—20 m straight walk and circular walk—using IMUs. In an ANCOVA model, we found a significant and large effect of the H&Y scores on step length in both tasks, and only a minor effect on step time. This study provides evidence that from the two potentially most important gait parameters currently accessible with wearable technology under supervised assessment strategies, step length changes substantially over the course of PD, while step time shows surprisingly little change in the progression of PD. These results show the importance of carefully evaluating quantitative gait parameters to make assumptions about disease progression, and the potential of the granular evaluation of symptoms such as gait deficits when monitoring chronic progressive diseases such as PD.

[Nordic walking in winter as the multitask training in patients with Parkinson's disease]

OBJECTIVE

To evaluate an influence of 8-week course of winter nordic walking as the multitask on the spatial-temporal characteristics of walking and motor disturbances in patients with Parkinson's disease (PD).

MATERIAL AND METHODS

Eleven patients (3 men and 8 women, mean age 66.82±3.97 years) with Hoehn and Yahr stage 1 to 2 PD were included in the study. Preliminary medical examination, including the anthropometric profile with the calculation of the body mass index (BMI), the grip strength on the right and left sides, spirometry, functional tests with the physical load (orthostatic test with the determination of systolic and diastolic blood pressure (SBP and DPB) and type of reaction (normal, hypertonic, hypotonic), the 6 Minute Walk Test, timed Up and Go test), was performed to evaluate the physical state. The evaluation of motor function was performed using the unified Parkinson's disease rating scale of the Movement Disorder Society (MDS UPDRS), part III. A 8-week course of nordic walking training was carried out at the certified track on the stadium localized outside of the city, in the wood and parks area in the winter.

RESULTS

Compared to the first training, gait velocity increased at the 3^rd session, the step length at the 6^th. The improvement of the spatial-temporal characteristics of walking was accompanied by the improvement of the motor function as measured by MDS UPDRS, part III.

CONCLUSION

Winter nordic walking as multitask is the effective measure of exercise treatment in patients with PD, because it improves the spatial-temporal characteristics of walking and the motor function.

Spatiotemporal characteristics of locomotor adaptation of walking with two handheld poles

Pole walking (PW) has received attention not only as a whole-body exercise that can be adapted for elderly people with poor physical fitness but also as a possible intervention for the restoration of gait function in normal walking without the use of poles (i.e., conventional walking CW). However, the characteristics of PW, especially how and why PW training affects CW, remain unclear. The purpose of this study was to examine the characteristics of locomotor adaptation in PW from the perspective of kinematic variables. For this purpose, we compared the locomotor adaptation in PW and CW to that when walking on a split-belt treadmill in terms of spatial and temporal coordination. The result showed that adaptations to the split-belt treadmill in PW and CW were found only in interlimb parameters (step length and double support time ratios (fast/slow limb)), not in intralimb parameters (stride length and stance time ratios). In these interlimb parameters, the movement patterns acquired through split-belt locomotor adaptations (i.e., the aftereffects) were transferred between CW and PW regardless of whether the novel movement patterns were learned in CW or PW. The aftereffects of double support time and step length learned in CW were completely washed out by the subsequent execution in PW. On the other hand, the aftereffect of double support time learned in PW was not completely washed out by the subsequent execution in CW, whereas the aftereffect of step length learned in PW was completely washed out by the subsequent execution in CW. These results suggest that the neural mechanisms related to controlling interlimb parameters are shared between CW and PW, and it is possible that, in interlimb coordination, temporal coordination is preferentially stored in adaptation during PW.

Effectiveness of 6-Week Nordic Walking Training on Functional Performance, Gait Quality, and Quality of Life in Parkinson's Disease

Background and objectives: Motor rehabilitation improves physical mobility and quality of life in Parkinson’s disease (PD). As specialized rehabilitation is expensive and resource-consuming, there is a need for simpler, cost-effective methods. The purpose of the study was to determine whether Nordic Walking (NW) training may support the management of motor disability in PD. Materials and Methods: Forty patients (median age 64.0 years, range 50–75 years) with idiopathic PD, Hoehn and Yahr stages II–III, were randomly assigned to NW or standard rehabilitation (SR) programs, comprising twelve rehabilitation sessions conducted bi-weekly throughout the 6-week study period. Results: Median Unified Parkinson’s Disease Rating Scale part III scores were significantly reduced with NW, by 8.5, and with SR, by 6.0 points (both p < 0.001), with significantly greater improvement with NW than with SR (p = 0.047). Gait quality and balance control, measured using the Dynamic Gait Index, improved with NW by a median of 8.0 and with SR by 5.5 points (both p < 0.001), with slightly greater improvement with NW, compared to the SR group (p = 0.064). Quality of life, assessed using the Parkinson’s Disease Questionnaire (PDQ-39), improved with NW by a median of 15 and with SR by 12 points, p = 0.001 and p = 0.008, respectively. Conclusions: The 6-week Nordic Walking program improves functional performance, quality of gait, and quality of life in patients with PD and has comparable effectiveness to standard rehabilitation.

Nordic walking influence on biomechanical parameters: a systematic review

INTRODUCTION

Nordic walking (NW) as a form of physical activity has been shown to have benefits in various domains, but little is known about the effect of NW on more specific biomechanical parameters. The purpose is to determine the impact of NW on the following parameters: walking speed/distance, muscle activation, spatiotemporal parameters, kinematics and ground reaction force.

EVIDENCE ACQUISITION

A literature search was carried out in different databases from October 2008 to October 2018. This review was conducted and reported in accordance with the PRISMA statement. Finally, 42 studies with a median PEDro Score of 5.5/10 were included.

EVIDENCE SYNTHESIS

The included studies reported increased walking distance (+14.8%, P<0.05), walking speed (+25.5%, P<0.05), and stride length (+10.4%, P<0.05), but decreased cadence (-6.2%, P<0.05). NW generally increased: muscle activation and strength for upper limbs; upper and lower limb range of motion, and ground reaction force.

CONCLUSIONS

NW has beneficial effects on many biomechanical parameters. It appears to be an effective way of doing physical activity and could be used in physical rehabilitation or in daily life.

Entropy of Real-World Gait in Parkinson's Disease Determined from Wearable Sensors as a Digital Marker of Altered Ambulatory Behavior

Parkinson’s disease (PD) is a common age-related neurodegenerative disease. Gait impairment is frequent in the later stages of PD contributing to reduced mobility and quality of life. Digital biomarkers such as gait velocity and step length are predictors of motor and cognitive decline in PD. Additional gait parameters may describe different aspects of gait and motor control in PD. Sample entropy (SampEnt), a measure of signal predictability, is a nonlinear approach that quantifies regularity of a signal. This study investigated SampEnt as a potential biomarker for PD and disease duration. Real-world gait data over a seven-day period were collected using an accelerometer (Axivity AX3, York, UK) placed on the low back and gait metrics extracted. SampEnt was determined for the stride time, with vector length and threshold parameters optimized. People with PD had higher stride time SampEnt compared to older adults, indicating reduced gait regularity. The range of SampEnt increased over 36 months for the PD group, although the mean value did not change. SampEnt was associated with dopaminergic medication dose but not with clinical motor scores. In conclusion, this pilot study indicates that SampEnt from real-world data may be a useful parameter reflecting clinical status although further research is needed involving larger populations.

The Therapeutic Effect of Nordic Walking on Freezing of Gait in Parkinson's Disease: A Pilot Study

Introduction. The effectiveness of the currently utilized therapies for FoG is limited. Several studies demonstrated a beneficial impact of Nordic walking (NW) on several gait parameters in Parkinson's disease, but only one paper reported reduction of freezing. Research Question. In the present study, the question is whether NW is an effective therapeutic intervention in FoG.

Occupational therapy with Nordic walking and therapeutic touch: A pilot study for multidisciplinary rehabilitation in Parkinson's disease

BACKGROUND

Physical exercise combined with occupational therapy (OT) can lead to a global improvement in personal well-being.

OBJECTIVE

To assess in PD patients: 1) if a rehabilitation program involving OT, Nordic walking (NW) and therapeutic touch (TT) yields motor/non-motor benefits; 2) if the time collocation of OT within the program influences results.

METHODS

This is a pilot study on 17 PD patients undergoing a 10-week rehabilitation program consisting of OT, NW and TT. Patients were randomized to receive OT in the first [Group 1, n = 8] vs. last five weeks [Group 2, n = 9] of the program. Scales (MMSE, FAB, BDI, UPDRS II and III, PDQ39 and AES-S) and 6MWT, Gait speed and length were assessed at three time-points.

RESULTS

Thirteen out of 17 patients were analyzed. 6MWT, Gait speed and length improved in time without between-group differences (p < 0.05) as did UPDRII, UPDRSIII, FAB and PDQ39 (p < 0.05). Baseline UPDRS II and III significantly determined Δ6MWT (adjusted R2 = 0.6738) and ΔGAIT speed (R2 = 0.6746) at multiple regression, while ΔGAIT length showed the best regression (adjusted R2 = 0.8247) with impact of age, gender and baseline PDQ39 (ADL and cognition dimensions).

CONCLUSIONS

Multidisciplinary rehabilitation including OT can improve motor and non-motor conditions in PD patients. The OT time-collocation at beginning or end of the rehabilitation program does not significantly affect results.

Overcoming randomness does not rule out the importance of inherent randomness for functionality

Randomness is intrinsic to many natural processes. It is also clear that, under certain conditions, disorders are not associated with functionality. Several examples in which overcoming, suppressing, or combining both randomness and non-randomness is required are drawn from various fields. However, the need to suppress or overcome randomness does not negate its importance under certain conditions and its significance in valid processes and organ functions. Randomness should be acknowledged rather than ignored or suppressed; it can be viewed, at worst, as a disturbing disorder that may be treated to produce order, or, at best, as a 'beneficial disorder' that can be considered as a higher level of functionality.

Improvement of Attention, Executive Functions, and Processing Speed in Elderly Women as a Result of Involvement in the Nordic Walking Training Program and Vitamin D Supplementation

Research indicates that life satisfaction declines with age, and cognitive abilities are gradually reduced—mainly attentional functioning and cognitive processing speed. Therefore, scientists seek to find protective factors and test possible intervention programs; moderately intensive physical activity stands out as particularly promising. In this context, we evaluated the influence of Nordic Walking training supported by vitamin D supplementation (as this nutrient is especially deficient in older people in Poland) on the cognitive and psychological functioning of elderly women. A total of 52 healthy elderly women took part in a Nordic Walking training program complemented by vitamin D supplementation. Cognitive functioning was assessed with the Trail Making Test and the D2 Test of Attention. Quality of life and severity of depressive symptoms were measured with the Short Form Health Survey and the Beck Depression Inventory 2. Significant improvements in all aspects of cognitive functioning was observed (p = 0.01–0.47). The study also showed a decrease in depressive symptoms (p = 0.026). Physical activity and adequate levels of vitamin D can be the key factors in maintaining self-reliance in old age. Involvement in Nordic Walking training, supported by vitamin D supplementation, can strengthen the cognitive functioning of older people—reflected in higher attentional capabilities, better executive functions, and improved cognitive processing speed.

Gait impairments in Parkinson's disease

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

Assessing Gait in Parkinson's Disease Using Wearable Motion Sensors: A Systematic Review

Abstract: Parkinson’s disease (PD) is a progressive neurodegenerative disorder. Gait impairments are common among people with PD. Wearable sensor systems can be used for gait analysis by providing spatio-temporal parameters useful to investigate the progression of gait problems in Parkinson disease. However, various methods and tools with very high variability have been developed. The aim of this study is to review published articles of the last 10 years (from 2008 to 2018) concerning the application of wearable sensors to assess spatio-temporal parameters of gait in patients with PD. We focus on inertial sensors used for gait analysis in the clinical environment (i.e., we do not cover the use of inertial sensors to monitor walking or general activities at home, in unsupervised environments). Materials and Methods: Relevant articles were searched in the Medline database using Pubmed. Results and Discussion: Two hundred ninety-four articles were initially identified while searching the scientific literature regarding this topic. Thirty-six articles were selected and included in this review. Conclusion: Wearable motion sensors are useful, non-invasive, low-cost, and objective tools that are being extensively used to perform gait analysis on PD patients. Being able to diagnose and monitor the progression of PD patients makes wearable sensors very useful to evaluate clinical efficacy before and after therapeutic interventions. However, there is no uniformity in the use of wearable sensors in terms of: number of sensors, positioning, chosen parameters, and other characteristics. Future research should focus on standardizing the measurement setup and selecting which spatio-temporal parameters are the most informative to analyze gait in PD. These parameters should be provided as standard assessments in all studies to increase replicability and comparability of results.

Complexity Matching: Restoring the Complexity of Locomotion in Older People Through Arm-in-Arm Walking

The complexity matching effect refers to a maximization of information exchange, when interacting systems share similar complexities. Additionally, interacting systems tend to attune their complexities in order to enhance their coordination. This effect has been observed in a number of synchronization experiments, and interpreted as a transfer of multifractality between systems. Finally, it has been shown that when two systems of different complexity levels interact, this transfer of multifractality operates from the most complex system to the less complex, yielding an increase of complexity in the latter. This theoretical framework inspired the present experiment that tested the possible restoration of complexity in older people. In young and healthy participants, walking is known to present 1/f fluctuations, reflecting the complexity of the locomotion system, providing walkers with both stability and adaptability. In contrast walking tends to present a more disordered dynamics in older people, and this whitening was shown to correlate with fall propensity. We hypothesized that if an aged participant walked in close synchrony with a young companion, the complexity matching effect should result in the restoration of complexity in the former. Older participants were involved in a prolonged training program of synchronized walking, with a young experimenter. Synchronization within the dyads was dominated by complexity matching. We observed a restoration of complexity in participants after 3 weeks, and this effect was persistent 2 weeks after the end of the training session. This work presents the first demonstration of a restoration of complexity in deficient systems.

Gait Complexity and Regularity Are Differently Modulated by Treadmill Walking in Parkinson's Disease and Healthy Population

Variability raises considerable interest as a promising and sensitive marker of dysfunction in physiology, in particular in neurosciences. Both internally (e.g., pathology) and/or externally (e.g., environment) generated perturbations and the neuro-mechanical responses to them contribute to the fluctuating dynamics of locomotion. Defective internal gait control in Parkinson's disease (PD), resulting in typical timing gait disorders, is characterized by the breakdown of the temporal organization of stride duration variability. Influence of external cue on gait pattern could be detrimental or advantageous depending on situations (healthy or pathological gait pattern, respectively). As well as being an interesting rehabilitative approach in PD, treadmills are usually implemented in laboratory settings to perform instrumented gait analysis including gait variability assessment. However, possibly acting as an external pacemaker, treadmill could modulate the temporal organization of gait variability of PD patients which could invalidate any gait variability assessment. This study aimed to investigate the immediate influence of treadmill walking (TW) on the temporal organization of stride duration variability in PD and healthy population. Here, we analyzed the gait pattern of 20 PD patients and 15 healthy age-matched subjects walking on overground and on a motorized-treadmill (randomized order) at a self-selected speed. The temporal organization and regularity of time series of walking were assessed on 512 consecutive strides and assessed by the application of non-linear mathematical methods (i.e., the detrended fluctuation analysis and power spectral density; and sample entropy, for the temporal organization and regularity of gait variability, respectively). A more temporally organized and regular gait pattern seems to emerge from TW in PD while no influence was observed on healthy gait pattern. Treadmill could afford the necessary framework to regulate gait rhythmicity in PD. Overall, the results support the hypothesis of a greater dependence to regulatory inputs as an explanatory factor of treadmill influence observed in PD. Also, since treadmill misrepresents the gait as more healthy than it is, the present findings underline that gait analysis using treadmill devices should be cautiously considered in PD and especially for gait variability assessment in gait lab.

Metabolic and kinematic parameters during walking with poles in Parkinson's disease

In healthy people, energy expenditure is generally higher during walking with poles (WP) than during conventional walking (W). In persons with Parkinson's disease (PD), walking is slower and may be associated with greater energy consumption, stride-to-stride variability, and difficulty in regulating stride length. The aim of this study was to determine whether treadmill WP at three different speeds could induce changes in gait kinematics and oxygen consumption in PD patients. The study sample was 20 patients with mild-to-moderate PD and 20 age-matched healthy controls. Subjects underwent 5-min W and WP treadmill tests at three different speeds (2.5, 3.5, and 4.5 km/h). Metabolic and gait parameters (ventilation, gas exchange, stride count and length) were recorded. As compared with the healthy controls, higher energy consumption (P < 0.05) (and other metabolic parameters), shorter stride, and reduced cadence (P < 0.05) were observed for the PD patients, independent of the walking technique. All subjects were noted to take longer strides during WP (P < 0.001), especially at the lowest treadmill speed. However, significantly higher energy consumption was observed only for the healthy controls (P < 0.05). No changes in metabolic parameters during WP were recorded; however, a substantial improvement in gait cycle length was noted for the PD patients.