Influence of visual cues on gait in Parkinson's disease during treadmill walking at multiple velocities

Testing protocols and measurement techniques when using pressure sensors for sport and health applications: A comparative review

Plantar pressure measurement systems are routinely used in sports and health applications to assess locomotion. The purpose of this review is to describe and critically discuss: (a) applications of the pressure measurement systems in sport and healthcare, (b) testing protocols and considerations for clinical gait analysis, (c) clinical recommendations for interpreting plantar pressure data, (d) calibration procedures and their accuracy, and (e) the future of pressure sensor data analysis. Rigid pressure platforms are typically used to measure plantar pressures for the assessment of foot function during standing and walking, particularly when barefoot, and are the most accurate for measuring plantar pressures. For reliable data, two step protocol prior to contacting the pressure plate is recommended. In-shoe systems are most suitable for measuring plantar pressures in the field during daily living or dynamic sporting movements as they are often wireless and can measure multiple steps. They are the most suitable equipment to assess the effects of footwear and orthotics on plantar pressures. However, they typically have lower spatial resolution and sampling frequency than platform systems. Users of pressure measurement systems need to consider the suitability of the calibration procedures for their chosen application when selecting and using a pressure measurement system. For some applications, a bespoke calibration procedure is required to improve validity and reliability of the pressure measurement system. The testing machines that are commonly used for dynamic calibration of pressure measurement systems frequently have loading rates of less than even those found in walking, so the development of testing protocols that truly measure the loading rates found in many sporting movements are required. There is clear potential for AI techniques to assist in the analysis and interpretation of plantar pressure data to enable the more complete use of pressure system data in clinical diagnoses and monitoring.

Force-sensing treadmill gait analysis system can detect gait abnormalities in haemophilia patients without arthropathy

BACKGROUND

Joint damage in patients with haemophilia (PwH) is commonly assessed by imaging, but few reports have described how structural changes in joints, for example, haemophilic arthropathy (HA)-affect gait ability.

OBJECTIVES

We evaluated gait function among PwH with HA, PwH without HA, and people without haemophilia (non-PwH) using a Zebris FDM-T treadmill (FDM-T), an easy-to-use gait assessment instrument with a force sensor matrix.

METHODS

The following gait parameters were collected: centre of pressure trajectory intersection (COPi) anterior/posterior variability, COPi lateral variability, COPi anterior/posterior symmetry, COPi lateral symmetry, single-limb support line (SLSL) length, and SLSL variability. Participants walked at their typical gait speed. The physical function of the PwH was assessed by the Hemophilia Joint Health Score (HJHS). Parameters were compared among the three groups.

RESULTS

Twelve PwH with HA, 28 PwH without HA, and 12 non-PwH were enrolled. Gait speed significantly differed between groups (non-PwH, 3.1 ± 0.7; PwH without HA, 2.0 ± 0.7; PwH with HA; 1.5 ± 0.4). The COPi anterior/posterior variability, COPi lateral variability, SLSL length, and SLSL variability were greater in the PwH groups than in the non-PwH group. The COPi lateral symmetry differed between PwH with HA and the other groups. The HJHS was not correlated with gait parameters among PwH with HA.

CONCLUSIONS

Gait parameters and speed were abnormal in both PwH with HA and PwH without HA. The FDM-T can be used to identify early stages of physical dysfunction that cannot be detected by conventional functional assessments such as the HJHS.

Visual feedback improves propulsive force generation during treadmill walking in people with Parkinson disease

Persons with Parkinson's disease experience gait alterations, such as reduced step length. Gait dysfunction is a significant research priority as the current treatments targeting gait impairment are limited. This study aimed to investigate the effects of visual biofeedback on propulsive force during treadmill walking in persons with Parkinson's. Sixteen ambulatory persons with Parkinson's participated in the study. They received real-time biofeedback of anterior ground reaction force during treadmill walking at a constant speed. Peak propulsive force values were measured and normalized to body weight. Spatiotemporal parameters were also assessed, including stride length and double support percent. Persons with Parkinson's significantly increased peak propulsive force during biofeedback compared to baseline (p <.0001, Cohen's dz = 1.69). Variability in peak anterior ground reaction force decreased across repeated trials (p <.0001, dz = 1.51). While spatiotemporal parameters did not show significant changes individually, stride length and double support percent improved marginally during biofeedback trials. Persons with Parkinson's can increase propulsive force with visual biofeedback, suggesting the presence of a propulsive reserve. Though stride length did not significantly change, clinically meaningful improvements were observed. Targeting push-off force through visual biofeedback may offer a potential rehabilitation technique to enhance gait performance in Persons with Parkinson's. Future studies could explore the long-term efficacy of this intervention and investigate additional strategies to improve gait in Parkinson's disease.

Gait Adaptability and the Effect of Ocular Disorders on Visually Guided Walking in Parkinson's Disease

Gait disorders are a disabling feature of Parkinson's disease (PD). To avoid falls, people with PD should be able to adequately adapt their gait. This requires correct response inhibition and integration of visual information. In this small pilot study, we investigated PD-related impairments in gait adaptability and the influence of ocular disorders thereon. Compared with controls, persons with PD were less able to adapt their gait in unexpected situations (U = 21.5, p = 0.013), with only a small influence of ocular disorders on precision stepping (U = 6, p = 0.012 in the ML-direction and in the AP-direction, (U = 20, p = 0.456). This shows that people with PD have more difficulty with precision stepping than healthy controls and experience more problems with adapting their gait. We found only a small impact of ocular disorders on successfully execute precision stepping. The ability to adapt gait, particularly in challenging environmental conditions or with impaired vision, may provide a useful assessment and training option for fall prevention in PD.

Investigating gait-responsive somatosensory cueing from a wearable device to improve walking in Parkinson's disease

Freezing-of-gait (FOG) and impaired walking are common features of Parkinson's disease (PD). Provision of external stimuli (cueing) can improve gait, however, many cueing methods are simplistic, increase task loading or have limited utility in a real-world setting. Closed-loop (automated) somatosensory cueing systems have the potential to deliver personalised, discrete cues at the appropriate time, without requiring user input. Further development of cue delivery methods and FOG-detection are required to achieve this. In this feasibility study, we aimed to test if FOG-initiated vibration cues applied to the lower-leg via wearable devices can improve gait in PD, and to develop real-time FOG-detection algorithms. 17 participants with Parkinson's disease and daily FOG were recruited. During 1 h study sessions, participants undertook 4 complex walking circuits, each with a different intervention: continuous rhythmic vibration cueing (CC), responsive cueing (RC; cues initiated by the research team in response to FOG), device worn with no cueing (NC), or no device (ND). Study sessions were grouped into 3 stages/blocks (A-C), separated by a gap of several weeks, enabling improvements to circuit design and the cueing device to be implemented. Video and onboard inertial measurement unit (IMU) data were analyzed for FOG events and gait metrics. RC significantly improved circuit completion times demonstrating improved overall performance across a range of walking activities. Step frequency was significantly enhanced by RC during stages B and C. During stage C, > 10 FOG events were recorded in 45% of participants without cueing (NC), which was significantly reduced by RC. A machine learning framework achieved 83% sensitivity and 80% specificity for FOG detection using IMU data. Together, these data support the feasibility of closed-loop cueing approaches coupling real-time FOG detection with responsive somatosensory lower-leg cueing to improve gait in PD.

Commercially available pressure sensors for sport and health applications: A comparative review

Pressure measurement systems have numerous applications in healthcare and sport. The purpose of this review is to: (a) describe the brief history of the development of pressure sensors for clinical and sport applications, (b) discuss the design requirements for pressure measurement systems for different applications, (c) critique the suitability, reliability, and validity of commercial pressure measurement systems, and (d) suggest future directions for the development of pressure measurements systems in this area. Commercial pressure measurement systems generally use capacitive or resistive sensors, and typically capacitive sensors have been reported to be more valid and reliable than resistive sensors for prolonged use. It is important to acknowledge, however, that the selection of sensors is contingent upon the specific application requirements. Recent improvements in sensor and wireless technology and computational power have resulted in systems that have higher sensor density and sampling frequency with improved usability - thinner, lighter platforms, some of which are wireless, and reduced the obtrusiveness of in-shoe systems due to wireless data transmission and smaller data-logger and control units. Future developments of pressure sensors should focus on the design of systems that can measure or accurately predict shear stresses in conjunction with pressure, as it is thought the combination of both contributes to the development of pressure ulcers and diabetic plantar ulcers. The focus for the development of in-shoe pressure measurement systems is to minimise any potential interference to the patient or athlete, and to reduce power consumption of the wireless systems to improve the battery life, so these systems can be used to monitor daily activity. A potential solution to reduce the obtrusiveness of in-shoe systems include thin flexible pressure sensors which can be incorporated into socks. Although some experimental systems are available further work is needed to improve their validity and reliability.

Acclimatization of force production during walking in persons with Parkinson's disease

Individuals with Parkinson's disease walk slowly, with short strides resulting in decreased mobility. Treadmill walking assessments are utilized to understand gait impairment in persons with Parkinson's disease and treadmill-based interventions to mobility have become increasingly popular. While walking on a treadmill, there is a reported initial acclimatization period where individuals adjust to the speed and dynamics of the moving belt before producing consistent walking patterns. It is unknown how much walking time is required for individuals with Parkinson's disease to acclimate to the treadmill. We investigated how spatiotemporal parameters and ground reaction forces changed during treadmill acclimatization. Twenty individuals with idiopathic Parkinson's (15 Males, 5 Females) walked for a five-minute treadmill session on an instrumented treadmill while motion capture data were collected. The measures of interest included ground reaction force measures (peak propulsive force, peak braking force, propulsive impulse, and braking impulse) and spatiotemporal measures (stride length, stride time, or double support time). Analyses demonstrated significantly increased propulsive impulse (p <.001) after the first minute, with no significant difference for the remaining minutes (p ≥ 0.395). There were no significant changes in the spatiotemporal measures (P =.065). These results quantify the stabilization of ground reaction force during the treadmill acclimatization period. Based on our findings, if steady-state gait is desired, we recommend participants walk for at least two minutes before data collection. Future clinical investigations should consider ground reaction force as sensitive parameters for evaluating gait in persons with Parkinson's disease in treadmill-based assessments or interventional therapies.

Efeito imediato da estimulação auditiva rítmica nos parâmetros espaços-temporais da marcha de idosos sedentários: um estudo piloto

Resumo Objetivos Avaliar o efeito imediato da estimulação auditiva rítmica (EAR) com música sobre os parâmetros espaços-temporais da marcha em idosos sedentários e analisar possíveis interações com os episódios de quedas. Métodos Estudo piloto de intervenção com idosos sedentários (n=15), idade ≥ 60 anos, ambos os sexos, independentes na marcha. Adicionalmente, os idosos foram divididos em dois grupos, caidores (n=5) e não caidores (n=10), baseado no histórico de quedas no último ano. A avaliação dos parâmetros espaços-temporais da marcha foi realizada através do teste de Caminhada de 10 metros executado em marcha livre (T0), repetido com suporte da EAR com música (T1) e executado em marcha livre novamente (T2). Para a análise dos dados, foram utilizados a ANOVA de medidas repetidas e a ANOVA (two-way) para comparação entre os grupos, com o post hoc de Tukey. O tamanho do efeito das intervenções também foi calculado. Resultados Houve redução significativa do tempo e do número de passos e um aumento da velocidade da marcha (p<0,0001; com efeito grande) entre os momentos T0-T1 e T0-T2. Ambos os grupos caidores e não caidores apresentaram redução significativa do tempo e do número de passos (p<0,0001) e aumento da velocidade (p<0,0001), mas apenas na variável cadência houve efeito do grupo e da interação tempo e grupo. Conclusão Verificou-se um efeito imediato positivo do uso da EAR nos parâmetros espaços-temporais da marcha de idosos sedentários com maior efeito na cadência de idosos não caidores.

Cueing Paradigms to Improve Gait and Posture in Parkinson's Disease: A Narrative Review

Progressive gait dysfunction is one of the primary motor symptoms in people with Parkinson’s disease (PD). It is generally expressed as reduced step length and gait speed and as increased variability in step time and step length. People with PD also exhibit stooped posture which disrupts gait and impedes social interaction. The gait and posture impairments are usually resistant to the pharmacological treatment, worsen as the disease progresses, increase the likelihood of falls, and result in higher rates of hospitalization and mortality. These impairments may be caused by perceptual deficiencies (poor spatial awareness and loss of temporal rhythmicity) due to the disruptions in processing intrinsic information related to movement initiation and execution which can result in misperceptions of the actual effort required to perform a desired movement and maintain a stable posture. Consequently, people with PD often depend on external cues during execution of motor tasks. Numerous studies involving open-loop cues have shown improvements in gait and freezing of gait (FoG) in people with PD. However, the benefits of cueing may be limited, since cues are provided in a consistent/rhythmic manner irrespective of how well a person follows them. This limitation can be addressed by providing feedback in real-time to the user about performance (closed-loop cueing) which may help to improve movement patterns. Some studies that used closed-loop cueing observed improvements in gait and posture in PD, but the treadmill-based setup in a laboratory would not be accessible outside of a research setting, and the skills learned may not readily and completely transfer to overground locomotion in the community. Technologies suitable for cueing outside of laboratory environments could facilitate movement practice during daily activities at home or in the community and could strongly reinforce movement patterns and improve clinical outcomes. This narrative review presents an overview of cueing paradigms that have been utilized to improve gait and posture in people with PD and recommends development of closed-loop wearable systems that can be used at home or in the community to improve gait and posture in PD.

Classification of gait patterns between patients with Parkinson's disease and healthy controls using phase space reconstruction (PSR), empirical mode decomposition (EMD) and neural networks

Parkinson's disease (PD) is a common neurodegenerative disorder that affects human's quality of life, especially leading to locomotor deficits such as postural instability and gait disturbances. Gait signal is one of the best features to characterize and detect movement disorders caused by a malfunction in parts of the brain and nervous system of the patients with PD. Various classification approaches using spatiotemporal gait variables have been presented earlier to classify Parkinson's gait. In this study we propose a novel method for gait pattern classification between patients with PD and healthy controls, based upon phase space reconstruction (PSR), empirical mode decomposition (EMD) and neural networks. First, vertical ground reaction forces (GRFs) at specific positions of human feet are captured and then phase space is reconstructed. The properties associated with the gait system dynamics are preserved in the reconstructed phase space. Three-dimensional (3D) PSR together with Euclidean distance (ED) has been used. These measured parameters demonstrate significant difference in gait dynamics between the two groups and have been utilized to form a reference variable set. Second, reference variables are decomposed into Intrinsic Mode Functions (IMFs) using EMD, and the third IMFs are extracted and served as gait features. Third, neural networks are then used as the classifier to distinguish between patients with PD and healthy controls based on the difference of gait dynamics preserved in the gait features between the two groups. Finally, experiments are carried out on 93 PD patients and 73 healthy subjects to assess the effectiveness of the proposed method. By using 2-fold, 10-fold and leave-one-out cross-validation styles, the correct classification rates are reported to be 91.46%, 96.99% and 98.80%, respectively. Compared with other state-of-the-art methods, the results demonstrate superior performance and the proposed method can serve as a potential candidate for the automatic and non-invasive classification between patients with PD and healthy subjects.

Neural Substrates of Cognitive Motor Interference During Walking; Peripheral and Central Mechanisms

Current gait control models suggest that independent locomotion depends on central and peripheral mechanisms. However, less information is available on the integration of these mechanisms for adaptive walking. In this cross-sectional study, we investigated gait control mechanisms in people with Parkinson’s disease (PD) and healthy older (HO) adults: at self-selected walking speed (SSWS) and at fast walking speed (FWS). We measured effect of additional cognitive task (DT) and increased speed on prefrontal (PFC) and motor cortex (M1) activation, and Soleus H-reflex gain. Under DT-conditions we observed increased activation in PFC and M1. Whilst H-reflex gain decreased with additional cognitive load for both groups and speeds, H-reflex gain was lower in PD compared to HO while walking under ST condition at SSWS. Attentional load in PFC excites M1, which in turn increases inhibition on H-reflex activity during walking and reduces activity and sensitivity of peripheral reflex during the stance phase of gait. Importantly this effect on sensitivity was greater in HO. We have previously observed that the PFC copes with increased attentional load in young adults with no impact on peripheral reflexes and we suggest that gait instability in PD may in part be due to altered sensorimotor functioning reducing the sensitivity of peripheral reflexes.

Basal ganglia and beyond: The interplay between motor and cognitive aspects in Parkinson's disease rehabilitation

Parkinson's disease (PD) is characterized by motor and cognitive dysfunctions, affecting the motor behaviour. We summarize evidence that the interplay between motor and cognitive approaches is crucial in PD rehabilitation. Rehabilitation is complementary to pharmacological therapy and effective in reducing the PD disturbances, probably acting by inducing neuroplastic effects. The motor behaviour results from a complex integration between cortical and subcortical areas, underlying the motor, cognitive and motivational aspects of movement. The close interplay amongst these areas makes possible to learn, control and express habitual-automatic actions, which are dysfunctional in PD. The physiopathology of PD could be considered the base for the development of effective rehabilitation treatments. As the volitional action control is spared in early-medium stages of disease, rehabilitative approaches engaging cognition permit to achieve motor benefits and appear to be the most effective for PD. We will point out data supporting the relevance of targeting both motor and cognitive aspects in PD rehabilitation. Finally, we will discuss the role of cognitive engagement in motor rehabilitation for PD.

Repeatability of spatiotemporal, plantar pressure and force parameters during treadmill walking and running

BACKGROUND

Instrumented treadmills with integrated pressure mats measure spatiotemporal, pressure and force parameters and are often used to investigate changes in gait patterns due to injury or rehabilitation.

RESEARCH QUESTION

What is the within- and between-day repeatability of such an instrumented treadmill for spatiotemporal parameters, peak pressures and forces during walking and running?

METHODS

Treadmill gait and running analysis were performed at 5.0, 6.5, and 9.0 km/h in 33 healthy adults (age: 31.6 ± 7.4 years; body mass index: 23.8 ± 3.2 kg/m²) once on day 1 and twice on day 7. For all three speeds, intraclass correlation coefficents (ICC) and smallest detectable differences (SDC) corresponding to 95% limits of agreement were calculated for spatiotemporal parameters and peak pressures and forces in the heel, midfoot, and forefoot regions.

RESULTS

All spatiotemporal parameters and peak forces in the heel, midfoot, and forefoot regions showed a good within- and between-day repeatability (ICCs > 0.878) for all gait speeds with within-day repeatability being generally higher. For peak pressures, only the heel and forefoot regions but not the midfoot region, showed good repeatability (ICC > 0.9) at all gait speeds. SDCs ranged from 1.5 to 2.5° for foot rotation, 4.4 to 6.6 cm for stride length, 0.7 to 2.5% for length of stance phases, and 2.8 to 9.2 N/cm² for peak pressures in all foot regions. For walking, SDCs of peak forces in the heel, midfoot and forefoot regions were below 60 N, and for running below 135 N.

SIGNIFICANCE

Except for peak pressures in the midfoot, spatiotemporal and kinetic gait parameters during walking and running showed a good within- and between-day repeatability. Hence, the investigated treadmill is suitable to analyze gait patterns and changes in gait patterns due to interventions.

Internally Versus Externally Cued Speech in Parkinson's Disease and Cerebellar Disease

PURPOSE

The purpose of this study was to examine the effects of an internally versus externally cued speech task on perceived understandability and naturalness in speakers with Parkinson's disease (PD) and cerebellar disease (CD).

METHOD

Sentences extracted from a covertly recorded conversation (internally cued) were compared to the same sentences read aloud (externally cued) by speakers with PD and a clinical comparison group of speakers with CD. Experienced listeners rated the speech samples using a visual analog scale for the perceptual dimensions of understandability and naturalness.

RESULTS

Results suggest that experienced listeners rated the speech of participants with PD as significantly more natural and more understandable during the reading condition. Participants with CD were also rated as significantly more understandable during the reading condition, but ratings of naturalness did not differ between conversation and reading.

CONCLUSIONS

Speech tasks can have a pronounced impact on perceived speech patterns. For individuals with PD, both understandability and naturalness can improve during reading tasks versus conversational tasks. The speech benefits from reading may be attributed to several mechanisms, including possible improvement from an externally cued speech task. These findings have implications for speech task selection in evaluating individuals with dysarthria.

Spatiotemporal treadmill gait measurements using a laser range scanner: feasibility study of the healthy young adults

OBJECTIVE

Spatio-temporal parameters are typically used for gait analysis. Although these parameters are measured by sophisticated systems such as 3D motion capture system or optoelectronic bars, these systems cannot be deployed easily because of their high costs, large space requirements and elaborate set-up. The purpose of this study is to develope a system for measuring spatiotemporal gait parameters using a laser range scanner during treadmill gait.

APPROACH

To calculate accurate spatiotemporal parameters, the differences between the laser range scanner measured values and the reference values obtained from a 3D motion capture system were investigated in thirty subjects. From measurements in time and position at foot contact/off, adjustments to compensate for the differences in time and position were derived. Then, to determine the validity of the proposed system, values from the proposed system and the reference system were compared in four additional subjects.

MAIN RESULTS

The results indicate that the data from the laser range scanner demonstrate certain differences in time and position compared with reference values. However, when compensation values were introduced, each spatiotemporal parameter correlated well with the reference values.

SIGNIFICANCE

This newer system is smaller, is easier to deploy and requires less training than the 3D motion capture system.

Temporal and spatial gait parameters in children with Cri du Chat Syndrome under single and dual task conditions

AIM

To describe temporal and spatial gait characteristics in individuals with Cri du Chat syndrome (CdCS) and to explore the effects of performing concurrent manual tasks while walking.

METHODS

The gait parameters of 14 participants with CdCS (mean age 10.3, range 3-20 years) and 14 age-matched controls (mean age 10.1, range 3-20 years) were collected using the GAITRite^® instrumented walkway. All participants first walked without any concurrent tasks and then performed 2 motor dual task walking conditions (pitcher and tray).

RESULTS

Individuals with CdCS took more frequent, smaller steps than controls, but, on average, had a comparable gait speed. In addition, there was a significant task by group interaction. Participants decreased gait speed, decreased cadence, decreased step length, and increased% time in double limb support under dual task conditions compared to single task conditions. However, the age-matched controls altered their gait for both manual tasks, and the participants with CdCS only altered their gait for the tray task.

INTERPRETATION

Although individuals with CdCS ambulate with a comparable gait speed to age-matched controls under single task conditions, they did not significantly alter their gait when carrying a pitcher with a cup of water inside, like controls. It is not clear whether or not individuals with CdCS had difficulty attending to task demands or had difficulty modifying their gait.

Auditory and visual cueing modulate cycling speed of older adults and persons with Parkinson's disease in a Virtual Cycling (V-Cycle) system

BACKGROUND

Evidence based virtual environments (VEs) that incorporate compensatory strategies such as cueing may change motor behavior and increase exercise intensity while also being engaging and motivating. The purpose of this study was to determine if persons with Parkinson's disease and aged matched healthy adults responded to auditory and visual cueing embedded in a bicycling VE as a method to increase exercise intensity.

METHODS

We tested two groups of participants, persons with Parkinson's disease (PD) (n = 15) and age-matched healthy adults (n = 13) as they cycled on a stationary bicycle while interacting with a VE. Participants cycled under two conditions: auditory cueing (provided by a metronome) and visual cueing (represented as central road markers in the VE). The auditory condition had four trials in which auditory cues or the VE were presented alone or in combination. The visual condition had five trials in which the VE and visual cue rate presentation was manipulated. Data were analyzed by condition using factorial RMANOVAs with planned t-tests corrected for multiple comparisons.

RESULTS

There were no differences in pedaling rates between groups for both the auditory and visual cueing conditions. Persons with PD increased their pedaling rate in the auditory (F 4.78, p = 0.029) and visual cueing (F 26.48, p < 0.000) conditions. Age-matched healthy adults also increased their pedaling rate in the auditory (F = 24.72, p < 0.000) and visual cueing (F = 40.69, p < 0.000) conditions. Trial-to-trial comparisons in the visual condition in age-matched healthy adults showed a step-wise increase in pedaling rate (p = 0.003 to p < 0.000). In contrast, persons with PD increased their pedaling rate only when explicitly instructed to attend to the visual cues (p < 0.000).

CONCLUSIONS

An evidenced based cycling VE can modify pedaling rate in persons with PD and age-matched healthy adults. Persons with PD required attention directed to the visual cues in order to obtain an increase in cycling intensity. The combination of the VE and auditory cues was neither additive nor interfering. These data serve as preliminary evidence that embedding auditory and visual cues to alter cycling speed in a VE as method to increase exercise intensity that may promote fitness.

Effects of Auditory Rhythm and Music on Gait Disturbances in Parkinson's Disease

Gait abnormalities, such as shuffling steps, start hesitation, and freezing, are common and often incapacitating symptoms of Parkinson’s disease (PD) and other parkinsonian disorders. Pharmacological and surgical approaches have only limited efficacy in treating these gait disorders. Rhythmic auditory stimulation (RAS), such as playing marching music and dance therapy, has been shown to be a safe, inexpensive, and an effective method in improving gait in PD patients. However, RAS that adapts to patients’ movements may be more effective than rigid, fixed-tempo RAS used in most studies. In addition to auditory cueing, immersive virtual reality technologies that utilize interactive computer-generated systems through wearable devices are increasingly used for improving brain–body interaction and sensory–motor integration. Using multisensory cues, these therapies may be particularly suitable for the treatment of parkinsonian freezing and other gait disorders. In this review, we examine the affected neurological circuits underlying gait and temporal processing in PD patients and summarize the current studies demonstrating the effects of RAS on improving these gait deficits.

Visual cues combined with treadmill training to improve gait performance in Parkinson’s disease: a pilot randomized controlled trial

Objective:

To evaluate the effects of visual cues combined with treadmill training on gait performance in patients with Parkinson’s disease and to compare the strategy with pure treadmill training.

Design:

Pilot, exploratory, non-blinded, randomized controlled trial.

Setting:

University Hospital of Munich, Germany.

Subjects:

Twenty-three outpatients with Parkinson’s disease (Hoehn and Yahr stage II–IV).

Interventions:

Patients received 12 training sessions within five weeks of either visual cues combined with treadmill training ( n = 12) or pure treadmill training ( n = 11).

Main measures:

Outcome measures were gait speed, stride length and cadence recorded on the treadmill. Functional tests included the Timed Up and Go Test, the Unified Parkinson’s Disease Rating Scale and the Freezing of gait-questionnaire. Assessments were conducted at baseline, after the training period and at two months follow-up.

Results:

After the training period ( n = 20), gait speed and stride length had increased in both groups ( p ⩽ 0.05). Patients receiving the combined training scored better in the Timed Up and Go Test compared with the patients receiving pure treadmill training ( p ⩽ 0.05). At two months follow-up ( n = 13), patients who underwent the combined training sustained better results in gait speed and stride length ( p ⩽ 0.05) and sustained the improvement in the Timed Up and Go Test ( p ⩽ 0.05).

Conclusions:

This pilot study suggests that visual cues combined with treadmill training have more beneficial effects on gait than pure treadmill training in patients with a moderate stage of Parkinson’s disease. A large-scale study with longer follow-up is required.

Sensory aspects of movement disorders

Movement disorders, which include disorders such as Parkinson's disease, dystonia, Tourette's syndrome, restless legs syndrome, and akathisia, have traditionally been considered to be disorders of impaired motor control resulting predominantly from dysfunction of the basal ganglia. This notion has been revised largely because of increasing recognition of associated behavioural, psychiatric, autonomic, and other non-motor symptoms. The sensory aspects of movement disorders include intrinsic sensory abnormalities and the effects of external sensory input on the underlying motor abnormality. The basal ganglia, cerebellum, thalamus, and their connections, coupled with altered sensory input, seem to play a key part in abnormal sensorimotor integration. However, more investigation into the phenomenology and physiological basis of sensory abnormalities, and about the role of the basal ganglia, cerebellum, and related structures in somatosensory processing, and its effect on motor control, is needed.

Reliability of spatiotemporal and kinetic gait parameters determined by a new instrumented treadmill system

Background

Despite the emerging use of treadmills integrated with pressure platforms as outcome tools in both clinical and research settings, published evidence regarding the measurement properties of these new systems is limited. This study evaluated the within– and between–day repeatability of spatial, temporal and vertical ground reaction force parameters measured by a treadmill system instrumented with a capacitance–based pressure platform.

Methods

Thirty three healthy adults (mean age, 21.5 ± 2.8 years; height, 168.4 ± 9.9 cm; and mass, 67.8 ± 18.6 kg), walked barefoot on a treadmill system (FDM–THM–S, Zebris Medical GmbH) on three separate occasions. For each testing session, participants set their preferred pace but were blinded to treadmill speed. Spatial (foot rotation, step width, stride and step length), temporal (stride and step times, duration of stance, swing and single and double support) and peak vertical ground reaction force variables were collected over a 30–second capture period, equating to an average of 52 ± 5 steps of steady–state walking. Testing was repeated one week following the initial trial and again, for a third time, 20 minutes later. Repeated measures ANOVAs within a generalized linear modelling framework were used to assess between–session differences in gait parameters. Agreement between gait parameters measured within the same day (session 2 and 3) and between days (session 1 and 2; 1 and 3) were evaluated using the 95% repeatability coefficient.

Results

There were statistically significant differences in the majority (14/16) of temporal, spatial and kinetic gait parameters over the three test sessions (P < .01). The minimum change that could be detected with 95% confidence ranged between 3% and 17% for temporal parameters, 14% and 33% for spatial parameters, and 4% and 20% for kinetic parameters between days. Within–day repeatability was similar to that observed between days. Temporal and kinetic gait parameters were typically more consistent than spatial parameters. The 95% repeatability coefficient for vertical force peaks ranged between ± 53 and ± 63 N.

Conclusions

The limits of agreement in spatial parameters and ground reaction forces for the treadmill system encompass previously reported changes with neuromuscular pathology and footwear interventions. These findings provide clinicians and researchers with an indication of the repeatability and sensitivity of the Zebris treadmill system to detect changes in common spatiotemporal gait parameters and vertical ground reaction forces.

Simple method to reduce the effect of patient positioning variation on three-dimensional motion analysis during treadmill gait

Recently, three-dimensional (3D) closed curve trajectories of markers placed at strategic body locations, called cyclograms or Lissajous-like graphs, are used for treadmill gait analysis. A simple method is presented to reduce the effect of patient positioning variation. After breaking down movement into three components (anterior-posterior, medial-lateral and superior-inferior), the time-series data and time-inverted data are serially concatenated. A fast Fourier transform (FFT) is done, and a high-pass filter (except 0 Hz) is applied to the anterior-posterior and medial-lateral components. Next an inverse FFT is executed, and the posterior half of the outcome, corresponding to time-inverted data, is deleted. The 3D closed curve is then reconstructed. Results showed that the proposed method was able to reduce the effect of patient positioning variation. Since the adjusted curve is simply a symbolized gait pattern, the method might be useful as an adjunct tool in observational gait analysis.

[Visual cues as a therapeutic tool in Parkinson's disease. A systematic review]

Sensory stimuli or sensory cues are being used as a therapeutic tool for improving gait disorders in Parkinson's disease patients, but most studies seem to focus on auditory stimuli. The aim of this study was to conduct a systematic review regarding the use of visual cues over gait disorders, dual tasks during gait, freezing and the incidence of falls in patients with Parkinson to obtain therapeutic implications. We conducted a systematic review in main databases such as Cochrane Database of Systematic Reviews, TripDataBase, PubMed, Ovid MEDLINE, Ovid EMBASE and Physiotherapy Evidence Database, during 2005 to 2012, according to the recommendations of the Consolidated Standards of Reporting Trials, evaluating the quality of the papers included with the Downs & Black Quality Index. 21 articles were finally included in this systematic review (with a total of 892 participants) with variable methodological quality, achieving an average of 17.27 points in the Downs and Black Quality Index (range: 11-21). Visual cues produce improvements over temporal-spatial parameters in gait, turning execution, reducing the appearance of freezing and falls in Parkinson's disease patients. Visual cues appear to benefit dual tasks during gait, reducing the interference of the second task. Further studies are needed to determine the preferred type of stimuli for each stage of the disease.