Constraints on the kinetic, kinematic and spatiotemporal parameters of gait in Parkinson's disease

Gait variability in Parkinson's disease: an indicator of non-dopaminergic contributors to gait dysfunction?

Gait variability has potential utility as a predictive measure of dysfunction in Parkinson's disease (PD). Current understanding implicates non-dopaminergic pathways. This study investigated the explanatory characteristics of gait variability in PD on and off medication under single and dual task conditions. Fifty people with PD were assessed twice at home (on and off L: -dopa) whilst walking under single and dual task conditions, and variability (coefficient of variation, CV) was calculated for stride time and double limb support (DLS) time. Hierarchical regression analysis was used to identify predictors. The first block of variables included age, gait speed, depression (Hospital Anxiety and Depression Scale) and fatigue (Multidimensional Fatigue Inventory), and the second block included motor severity (UPDRS III), executive function (Hayling and Brixton) and attention (Test of Everyday Attention). Motor severity predicted stride time variability and DLS time variability independent of L: -dopa during single task gait. Dual task gait yielded a more complex picture. Depression made a unique contribution of 9.0% on medication and 5.0% off medication to stride time variability, and visual attention and younger age contributed to DLS variability on medication, explaining 3% and 2%, respectively. Motor severity predicted DLS variability off medication, explaining 74% of variance. Different characteristics explain the two measures of gait variability, pointing to different control mechanisms.

Using a shoe mounted tri-axial accelerometer to detect kinematic changes during stiff ankle walking

Ubiquitous analysis of gait is a rapidly emerging field in which research and commercial development has been focused mainly on determining spatio-temporal parameters. In this preliminary research we have developed an algorithm to determine gait metrics from a shoe mounted accelerometer and compared them with concurrent kinematic data. Subjects were tested at different walking speeds as well as an artificially induced stiff ankle condition, to determine what metrics estimate kinematic changes that are related to speed and those that are related to real kinematic changes. These preliminary findings suggest that accelerometer outputs from the foot combined with contextual knowledge of the general walking speed of the subject can be used to estimate ankle plantar flexion angular velocity in terminal stance.

Gait analysis comparing Parkinson's disease with healthy elderly subjects

There is a lack of studies comparing the kinematics data of idiopathic Parkinson's disease (IPD) patients with healthy elder (HE) subjects, and when there is such research, it is not correlated to clinical measures.

OBJECTIVE

To compare the spatio-temporal and kinematic parameters of Parkinsonian gait with the HE subjects group and measure the relation between these parameters and clinical instruments.

METHOD

Twelve patients with IPD and fifteen HE subjects were recruited and evaluated for clinical instruments and gait analysis.

RESULTS

There were statistically significant differences between HE group and the IPD group, in stride velocity, in stride length (SL), and in the hip joint kinematic data: on initial contact, on maximum extension during terminal contact and on maximum flexion during mid-swing. Regarding the clinical instruments there were significant correlated with in stride velocity and SL.

CONCLUSION

Clinical instruments used did not present proper psychometric parameters to measure the IPD patient's gait, while the 3D system characterized it better.

Mechanisms involved in treadmill walking improvements in Parkinson's disease

Patients with Parkinson's disease (PD) improve gait after treadmill training and while they are walking over the treadmill. However, the mechanisms of these improvements have not been addressed. We designed a treadmill simulator without a belt that could move on a walkway in a constant speed, in order to explore the mechanism underlying treadmill walking improvements in PD. All subjects were tested in three different sessions (treadmill, simulator(assisted) and simulator(not assisted)). In each session, subjects first walked overground and then walked using the treadmill or simulator with the hands over the handrails (simulator(assisted)) or with the hands free (simulator(not assisted)). Step length, cadence, double support time, swing time, support time and the coefficient of variation (CV) of step time and double support time were recorded. Over the treadmill PD patients increased their step length and reduced significantly their cadence and CV of double support time in comparison with overground walking. In the simulator(assisted) condition PD patients reduced significantly the CV of double support time in comparison with overground walking. With the simulator(not assisted) both groups decreased their step length and increased their cadence and CV of double support time, compared with walking overground. These findings suggest that the step length improvement observed in PD patients, walking over a treadmill, is due to the proprioceptive information generated by the belt movement, since no improvement was reported when patients using a treadmill simulator.

Gait analysis in patients with Parkinson's disease off dopaminergic therapy

OBJECTIVE

To compare time-distance, kinematic, and kinetic gait parameters in patients with idiopathic Parkinson's disease (PD) off dopaminergic therapy with a group of healthy control subjects.

DESIGN

A group-comparison study.

SETTING

Gait analysis laboratory.

PARTICIPANTS

Patients with PD (n=20) and healthy age-matched controls (n=20).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Time-distance, kinematic, and kinetic gait variables.

RESULTS

PD patients walked slower with shorter stride-length, comparable cadence, and longer double support times. Kinematics showed a reduction of the range of motion in the hip, knee, and ankle joints. Maximum hip extension and the ankle plantar flexion were significantly reduced. Kinetic gait parameters showed reduced push-off ankle power and lift-off hip power generation. Strong correlations between these important body advancement mechanisms and the walking velocity were observed.

CONCLUSIONS

In addition to previously described dysfunctional kinematics, abnormal kinetic parameters play an important role in the characterization of gait in PD patients off therapy. Hence, these parameters could be used to document treatment effects of parkinsonian gait disorders.

[Deep brain stimulation and gait disorders in Parkinson disease]

INTRODUCTION

Gait disorders and freezing of gait (FOG) are seen in most patients with advanced Parkinson disease. Response to levodopa and deep brain stimulation is variable across patients.

STATE OF ART

Thalamic stimulation is ineffective on gait and can even worsen balance when bilaterally applied. Pallidal stimulation moderately improves gait disorders and FOG although this effect tends to wane after three to five years. Stimulation of the subthalamic nucleus (STN) improves levodopa-responsive gait disorders and FOG. However, some patients worsen after STN stimulation and others are better improved under levodopa than under STN stimulation. Synergistic effects of the two treatments have been reported. As for pallidal stimulation, there is a failure of long-term STN stimulation to improve gait, probably due to the involvement of non-dopaminergic pathways as the disease progresses. Levodopa-resistant gait disorders and FOG do not usually benefit from STN stimulation. In the rare cases of levodopa-induced FOG, STN stimulation may be indirectly effective, as it enables reduction or arrest of the levodopa treatment.

PERSPECTIVES

Pedunculopontine nucleus stimulation has recently been performed in small groups of patients with disabling gait disorders and FOG. Although encouraging, the first results need to be confirmed by controlled studies involving larger series of patients.

CONCLUSIONS

Overall, gait disorders remain a motor PD symptom that is little improved, or only temporarily, by current pharmacological and surgical treatments. Patient management is complex.

Effects of postural threat on walking features of Parkinson's disease patients

This study investigated whether or not gait kinematics among healthy older individuals and Parkinson's disease (PD) patients are influenced by postural threat. Eight healthy older individuals and eight PD patients were examined while walking at self-selected velocities, under three conditions of postural threat: unconstrained floor; constrained floor (19cm wide); constrained and elevated floor (19cm wide by 10cm high). Independent of the surface conditions, due to motor disturbances caused by the PD these patients walked slower, with shorter strides, and spent more time in the double support phase and less time in the swing phase than did their matched controls. Increases in postural threat resulted in altered gait kinematics for all subjects. Specifically, stride length, stride velocity, cadence, and heel contact velocity decreased, and stride duration and double support duration increased relative to increases in postural threat. All gait alterations were the result of participants' attempts to facilitate locomotion control and maintain stability. The results of this study reveal that width and height constraints effectively perturbed the balance of all of the walking older individuals. The PD patients were able to modulate gait parameters when faced by a postural threat task.

Effects of tango on functional mobility in Parkinson's disease: a preliminary study

Recent research has shown that dance, specifically tango, may be an appropriate and effective strategy for ameliorating functional mobility deficits in people who are frail and elderly. Individuals with Parkinson's disease (PD) experience declines in functional mobility that may be even more pronounced than those experienced by frail elderly individuals without PD. The purpose of this study was to compare the effects of two movement programs: tango classes or exercise classes. Nineteen subjects with PD were randomly assigned to a tango group or a group exercise class representative of the current classes offered in our geographical area for individuals with PD. Subjects completed a total of 20 tango or exercise classes and were evaluated the week before and the week following the intervention. Both groups showed significant improvements in overall Unified Parkinson's Disease Rating Scale (UPDRS) score and nonsignificant improvements in self-reported Freezing of Gait. In addition, the tango group showed significant improvements on the Berg Balance Scale. The exercise group did not improve on this measure. Finally, the tango group showed a trend toward improvement on the Timed Up and Go test that was not observed in the exercise group. Future studies with a larger sample are needed to confirm and extend our observation that tango may be an effective intervention to target functional mobility deficits in individuals with PD.

Analyse de la marche dans la maladie de Parkinson par enregistrement baropodométrique à l’aide de semelles embarquées

INTRODUCTION

The literature reports some studies describing the walking pattern of patients with Parkinson's disease, its deterioration with disease severity and the effects of various treatments. Other studies concerned the plantar pressure distribution when walking. The aim of this study was to validate the use of baropodometric measurements for gait analysis of parkinsonian patients at various stages of disease severity and in on and off phases.

METHODS

Fifteen normal control subjects and fifteen parkinsonian patients equipped with a plantar pressure measurement system performed walking tests. The parkinsonian patients performed the walking tests in off phase then in on phase. A clinical examination was performed to score the motor handicap on the UPDRS scale.

RESULTS

Analysis of the plantar pressures of the parkinsonian subjects under various footprint areas detected significant baropodometric differences compared with controls, between groups with different UPDRS scores, and before and after L-Dopa treatment.

CONCLUSIONS

Plantar pressures measurements allow a sufficiently fine discrimination for using it to detect parkinsonism and monitor patients with Parkinson's disease.

The effects of visual rhythms and optic flow on stride patterns of patients with Parkinson's disease

This study was aimed at determining the effects of rhythmic visual cueing under changing visual conditions on stride frequency in patients with Parkinson's disease (PD; n = 21) and healthy age matched controls (n = 7) while walking at different speeds on a treadmill. Stride frequency and stride length in patients with PD as well as controls were not rigidly coupled to walking speed and could be manipulated with walking speed as well as by using spatial and temporal rhythmic visual cues.

Locomotor disorders in patients at early stages of Parkinson's disease: a quantitative analysis

Several studies have been performed with automatic motion analysis techniques to investigated the locomotor disorders of patients with severe Parkinson's disease (PD). These are mainly related to steady-state walking. Aim of the present study was to investigate the presence and the degree of these disorders in patients at early stages of PD. For this purpose a group of patients with mild PD (H&Y < or =2) and a group of age-matched controls were assessed by means of multifactorial analysis of kinematic and kinetic variables, during the execution of the following motor tasks: steady-state walking, gait initiation and turning around an obstacle. Results showed that PD patients did not differ from controls in steady-state walking, while significant differences emerged in gait initiation and turning strategies. Main differences consisted in a limitation of the amplitude of the imbalance phase and of the first step, and, for the turning task, in a delayed initiation of the turning movement, with an altered head-trunk rotational strategy. It is concluded that patients in early stages of PD do not reveal, during steady state walking, consistent impairments of kinematic and kinetic patterns typical of severe PD patients. Nevertheless, they present significant alterations in transient conditions such as gait initiation and change of walking direction. The above results suggest that a quantitative analysis of locomotor tasks which imply the transition from one condition to another, could provide parameters useful for the characterization of early stage PD patients and, potentially, markers for a precox differential diagnosis respect other neurodegenerative diseases characterized by parkinsonisms.

Quantitative gait analysis in Parkinson's disease: comparison with a healthy control group

OBJECTIVE

To compare gait parameters in Parkinson's disease (PD) during the on-phase of medication cycle with those of healthy elderly control subjects.

DESIGN

A group-comparison study.

SETTING

Gait analysis laboratory of a university hospital.

PARTICIPANTS

Fifteen patients with PD and 9 healthy elderly controls.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Spatiotemporal, kinematic, and kinetic gait parameters.

RESULTS

The PD spatiotemporal results showed a significant reduction in step length and walking velocity compared with controls. In the kinematics, the major feature of the PD group was a markedly reduced ankle plantarflexion excursion (at 50%-60% of the gait cycle). Most important, the kinetics showed reduced ankle push-off power and hip pull-off power. Unlike the control subjects, the patients with PD did not show any correlation between ankle generation (push-off) power and stride length ( r =.19) or with gait speed ( r =.29). Correction for walking velocity did not result in significant changes in the kinetics between the groups.

CONCLUSIONS

Reduced ankle (push-off) power generation and reduced hip flexion (pull-off) power persisted in PD gait despite being tested in the on-phase of the medication cycle. Lack of a correlation between ankle and hip power generation and walking velocity suggests that peripheral and central factors contribute to lack of forward progression. Patients with PD may benefit from intervention strategies that correct the kinematic and the kinetic gait components.

Training with Verbal Instructional Cues Results in Near-term Improvement of Gait in People with Parkinson Disease

PURPOSE

To assess immediate and near-term effects of an instructional set on select gait parameters in people living with Parkinson disease (PD).

SUBJECTS

Five individuals with early stage PD participated in a within subject design in Part One. Eleven individuals with early stage PD were randomly assigned to a treatment group (n = 5) or a control group (n = 6) in Part Two.

METHODS

The treatment consisted of a 10-day training program of walking 1800 feet per day and with the instructions to take long steps. Testing occurred before treatment (baseline), immediately after treatment, one week after treatment, and one month after treatment. Measurements of step length, velocity, and cadence were taken without the use of the instructional set.

RESULTS

There was a significant increase in step length and velocity and a significant decrease in cadence between baseline and all post-test measures for part one. For part 2, step length of the treatment group significantly increased between baseline and all 3 post-tests and there was a significant difference between the treatment group and control group at all posttests for step length.

CONCLUSIONS

The instructional set was effective in improving parameters of gait for at least 4 weeks. These data support the concept that people with Parkinson disease have a potential for motor learning.

Análisis de la marcha en la enfermedad de Parkinson y su respuesta al tratamiento dopaminérgico

BACKGROUND AND OBJECTIVE

The objective of this study was to analyze the gait abnormalities in patients with idiopathic Parkinson's disease (PD), and their response to dopaminergic treatment.

PATIENTS AND METHOD

15 patients and 15 healthy age-matched subjects were included for comparison between pathologic and "normal" gait, and 24 PD patients were included to assess the effects of treatment. Gait analysis was achieved with a new 3D-photogrammetry system.

RESULTS

Patients had significative lower velocity, stride length, step length and hip and knee ranges when compared with control subjects. There were no differences in cadence, step width and relative times of gait-cycle. There were no differences in the patients' gait variables after administration of a dopaminergic medication.

CONCLUSIONS

Gait analysis allows quantification of gait disturbances in patients with PD and the potential effects of treatment. The results of this study suggest a certain degree of "levodopa-resistance" in gait in these patients.

Effects of bilateral subthalamic stimulation on gait kinematics and kinetics in Parkinson?s disease

Subthalamic nucleus (STN) stimulation, a recent surgical approach to Parkinson's disease (PD), has been shown to be effective in relieving motor symptoms. The present study carried out a full body gait analysis, during overground walking, on ten PD patients with bilaterally implanted STN stimulation devices. Walking performance was analyzed on the same day, in four conditions (Stim Off-Med Off, Stim On-Med Off, Stim Off-Med On, Stim On-Med On). The results showed that, on average, STN stimulation alone (S+M-) and L-dopa alone (S-M+), significantly increased gait speed, stride length and the lower limb joint Range of Motion (ROM) with respect to the basal condition (S-M-); also cadence was found to play a role in velocity increase, particularly when L-dopa was administered. Both treatments improved pelvis and trunk kinematics, and power production at the ankle and hip joints. The combination of the two treatments (S+M+) produced an additional effect on gait speed, stride length, ROM of knee and ankle joints, pelvis obliquity and trunk inclination. Given the additive and synergistic effects, it can be hypothesized that the two treatments have different mechanisms of action. Our results confirm the findings of earlier studies that employed treadmill walking.

Gait assessment in Parkinson's disease: toward an ambulatory system for long-term monitoring

An ambulatory gait analysis method using body-attached gyroscopes to estimate spatio-temporal parameters of gait has been proposed and validated against a reference system for normal and pathologic gait. Later, ten Parkinson's disease (PD) patients with subthalamic nucleus deep brain stimulation (STN-DBS) implantation participated in gait measurements using our device. They walked one to three times on a 20-m walkway. Patients did the test twice: once STN-DBS was ON and once 180 min after turning it OFF. A group of ten age-matched normal subjects were also measured as controls. For each gait cycle, spatio-temporal parameters such as stride length (SL), stride velocity (SV), stance (ST), double support (DS), and gait cycle time (GC) were calculated. We found that PD patients had significantly different gait parameters comparing to controls. They had 52% less SV, 60% less SL, and 40% longer GC. Also they had significantly longer ST and DS (11% and 59% more, respectively) than controls. STN-DBS significantly improved gait parameters. During the stim ON period, PD patients had 31% faster SV, 26% longer SL, 6% shorter ST, and 26% shorter DS. GC, however, was not significantly different. Some of the gait parameters had high correlation with Unified Parkinson's Disease Rating Scale (UPDRS) subscores including SL with a significant correlation (r = -0.90) with UPDRS gait subscore. We concluded that our method provides a simple yet effective way of ambulatory gait analysis in PD patients with results confirming those obtained from much more complex and expensive methods used in gait labs.

Investigating body motion patterns in patients with Parkinson's disease using matching pursuit algorithm

Several recent studies have quantified abnormalities in Parkinsonian gait. However, few studies have attempted to quantify the regularity of body motion during walking in patients with Parkinson's disease. The aim of the paper was to characterise body motion patterns in healthy, elderly subjects and patients with Parkinson's disease during walking. Body motion was recorded during walking for 16 patients with Parkinson's disease and ten healthy, elderly subjects using a tri-axial accelerometer device. To characterise the body motion patterns, time-frequency patterns of the body acceleration signal were estimated using a matching pursuit algorithm. Data from the study showed that the healthy, elderly subjects and patients with Parkinson's disease had different time-frequency patterns. The time-frequency patterns were classified into four distinct patterns based on their time durations: vertical (< 0.15 s), circular (0.15-0.5 s), short horizontal (0.5-2.0 s) and long horizontal (> 2.0 s). The data showed that the energy of the long horizontal patterns, representing long-term smooth and regular (rhythmic) activities, significantly decreased, but the energy of the circular patterns, representing irregular activities, increased in the patients with mild Parkinson's disease, compared with those of the healthy, elderly subjects (p < 0.01). Futhermore, these features were seen more clearly in the body motions of severe case patients than is that of mild case patients. It was concluded that these differences are probably due to a lack of ability to control normal and smooth movement is Parkinson's disease.

Fractal dynamics of body motion in patients with Parkinson's disease

In this paper, we assess the complexity (fractal measure) of body motion during walking in patients with Parkinson's disease. The body motion of 11 patients with Parkinson's disease and 10 healthy elderly subjects was recorded using a triaxial accelerometry technique. A triaxial accelerometer was attached to the lumbar region. An assessment of the complexity of body motion was made using a maximum-likelihood-estimator-based fractal analysis method. Our data suggest that the fractal measures of the body motion of patients with Parkinson's disease are higher than those of healthy elderly subjects. These results were statistically different in the X (anteroposterior), Y (lateral) and Z (vertical) directions of body motion between patients with Parkinson's disease and the healthy elderly subjects (p < 0.01 in X and Z directions and p < 0.05 in Y direction). The complexity (fractal measure) of body motion can be useful to assess and monitor the output from the motor system during walking in clinical practice.

The power of cueing to circumvent dopamine deficits: a review of physical therapy treatment of gait disturbances in Parkinson's disease

Gait disturbances are among the primary symptoms of Parkinson's disease (PD) and contribute significantly to a patient's loss of function and independence. Standard treatment includes antiparkinsonian drugs, primarily levodopa. In addition to the standard drug regime, physical therapy is often prescribed to help manage the disease. In recent years, there have been promising reports of physical therapy programs combined with various types of sensory cueing for PD. In this brief review of the literature, we summarize the evidence regarding the clinical efficacy of different physical therapy programs for PD, specifically with respect to improving gait. We also discuss the potential therapeutic mechanisms of sensory cueing and review the studies that have used cueing in the treatment of gait in PD. This review of the literature shows two key findings: (1) despite its relatively long history, the evidence supporting the efficacy of conventional physical therapy for treatment of gait in PD is not strong; and (2) although further investigation is needed, sensory cueing appears to be a powerful means of improving gait in PD.

Quantitative analysis of gait in Parkinson's disease: a pilot study on the effects of bilateral sub-thalamic stimulation

Four patients with Parkinson's disease who had a Subthalamic Nucleus (STN) stimulator implanted and four age-matched controls underwent gait analysis using a three-dimensional system. STN stimulation substantially improved most of the key variables in the patients, without producing inefficient compensatory movements of the trunk. A reduction of ankle power production during push off was the most persistent abnormality seen when the patients were stimulated. We also found a reduction of trunk lateral bending and torsion when the patients were not stimulated when compared with controls.

The effect of a home physiotherapy program for persons with Parkinson's disease

The purpose of this study was to evaluate the effect of a home physiotherapy program for persons with Parkinson's disease. Thirty-three patients took part in the study using a within-subject controlled design. Functional activities including walking and carrying out transfers were measured at home and in the hospital before and after a 6-week baseline period, after 6 weeks home physiotherapy and after 3 months follow-up. Spatiotemporal and plantar force variables of gait were determined with video and pododynography. Treatment provided by community physiotherapists consisted of teaching cueing and conscious movement control 3 times a week. The study revealed that patients had significantly higher scores on a functional activity scale after treatment in the home setting and to a lesser degree in hospital, a result, which was partly sustained at follow-up. However, duration of the transfer movements, spatiotemporal and plantar force variables were not significantly improved except for stride length. The results support application and development of the treatment concept and highlight that physiotherapy aimed at improving function in Parkinson's disease is best provided in the home situation.

The biomechanics and motor control of gait in Parkinson disease

Parkinson disease is a progressive neurological condition characterised by hypokinesia (reduced movement), akinesia (absent movement), tremor, rigidity and postural instability. These movement disorders are associated with a slow short-stepped, shuffling gait pattern. Analysis of the biomechanics of gait in response to medication, visual cues, attentional strategies and neurosurgery provides insight into the nature of the motor control deficit in Parkinson disease and the efficacy of current therapeutic interventions. In this article we supplement a critical evaluation of the Parkinson disease gait literature with two case examples. The first case describes the kinematic gait response of an individual with Parkinson disease to visual cues in the "off" phase of the levodopa medication cycle. The second case investigates the biomechanics and motor control of turning during walking in a patient with Parkinson disease compared with elderly and young control subjects. The results are interpreted in light of the need for gait analysis to investigate complex functional walking tasks rather than confining assessment to straight line walking, which has been the trend to date.

Movement Disorders in People With Parkinson Disease: A Model for Physical Therapy

People who are diagnosed with idiopathic Parkinson disease (PD) experience movement disorders that, if not managed, can lead to considerable disability. The premise of this perspective is that physical therapy for people with PD relies on clinicians having: (1) up-to-date knowledge of the pathogenesis of movement disorders, (2) the ability to recognize common movement disorders in people with PD, (3) the ability to implement a basic management plan according to a person's stage of disability, and (4) problem-solving skills that enable treatment plans to be tailored to individual needs. This article will present a model of physical therapy management for people with idiopathic PD based on contemporary knowledge of the pathogenesis of movement disorders in basal ganglia disease as well as a review of the evidence for physical therapy interventions. The model advocates a task-specific approach to training, with emphasis on treating people with PD-related movement disorders such as hypokinesia and postural instability within the context of functional tasks of everyday living such as walking, turning over in bed, and manipulating objects. The effects of medication, cognitive impairment, the environment, and coexisting medical conditions are also taken into consideration. An argument is put forward that clinicians need to identify core elements of physical therapy training that apply to all people with PD as well as elements specific to the needs of each individual. A case history is used to illustrate how physical therapy treatment is regularly reviewed and adjusted according to the changing constellation of movement disorders that present as the disease progresses.