Reduced Stride Length Research Articles

Gait analysis in the early stage of Parkinson's disease with a machine learning approach.

Gait disorder is a prominent motor symptom in Parkinson's disease (PD), objective and quantitative assessment of gait is essential for diagnosing and treating PD, particularly in its early stage. This study utilized a non-contact gait assessment system to investigate gait characteristics between individuals with PD and healthy controls, with a focus on early-stage PD. Additionally, we trained two machine learning models to differentiate early-stage PD patients from controls and to predict MDS-UPDRS III score. Early-stage PD patients demonstrated reduced stride length, decreased gait speed, slower stride and swing speeds, extended turning time, and reduced cadence compared to controls. Our model, after an integrated analysis of gait parameters, accurately identified early-stage PD patients. Moreover, the model indicated that gait parameters could predict the MDS-UPDRS III score using a machine learning regression approach. The non-contact gait assessment system facilitates the objective and quantitative evaluation of gait disorder in PD patients, effectively distinguishing those in the early stage from healthy individuals. The system holds significant potential for the early detection of PD. It also harnesses gait parameters for a reasoned prediction of the MDS-UPDRS III score, thereby quantifying disease severity. Overall, gait assessment is a valuable method for the early identification and ongoing monitoring of PD.

Treatment effect analysis of the Frailty Care Bundle (FCB) in a cohort of patients in acute care settings

PurposeThe aim of this study is to explore the feasibility of using machine learning approaches to objectively differentiate the mobilization patterns, measured via accelerometer sensors, of patients pre- and post-intervention.MethodsThe intervention tested the implementation of a Frailty Care Bundle to improve mobilization, nutrition and cognition in older orthopedic patients. The study recruited 120 participants, a sub-group analysis was undertaken on 113 patients with accelerometer data (57 pre-intervention and 56 post-intervention), the median age was 78 years and the majority were female. Physical activity data from an ankle-worn accelerometer (StepWatch 4) was collected for each patient during their hospital stay. These data contained daily aggregated gait variables. Data preprocessing included the standardization of step counts and feature computation. Subsequently, a binary classification model was trained. A systematic hyperparameter optimization approach was applied, and feature selection was performed. Two classifier models, logistic regression and Random Forest, were investigated and Shapley values were used to explain model predictions.ResultsThe Random Forest classifier demonstrated an average balanced accuracy of 82.3% (± 1.7%) during training and 74.7% (± 8.2%) for the test set. In comparison, the logistic regression classifier achieved a training accuracy of 79.7% (± 1.9%) and a test accuracy of 77.6% (± 5.5%). The logistic regression model demonstrated less overfitting compared to the Random Forest model and better performance on the hold-out test set. Stride length was consistently chosen as a key feature in all iterations for both models, along with features related to stride velocity, gait speed, and Lyapunov exponent, indicating their significance in the classification.ConclusionThe best performing classifier was able to distinguish between patients pre- and post-intervention with greater than 75% accuracy. The intervention showed a correlation with higher gait speed and reduced stride length. However, the question of whether these alterations are part of an adaptive process that leads to improved outcomes over time remains.

Effects of mediolateral whole-body vibration during gait with additional cognitive load

Whole-body vibration (WBV) may increase musculoskeletal disorder risk among workers standing on vibrating surfaces for prolonged periods. Limited studies were conducted to comprehend WBV impact on individuals engaged in dynamic activities. This study explored the effects of different horizontal WBV frequencies on gait parameters, lower limb kinematics, and the cognitive response of healthy subjects. Forty participants walked at constant speed on a treadmill mounted on a horizontal shaker providing harmonic vibration with an amplitude of 1 m/s2 and frequencies 2–10 Hz, with inversely proportional amplitudes. A Psychomotor Vigilance Test measured reaction time while a motion capture system recorded walking kinematics. ANOVA results revealed no significant impact of vibration frequencies on the reaction time. At 2 Hz, alterations in gait spatiotemporal parameters were significant, with reduced stride length, stride time, step length, and stance time and increased step width and cadence. Similarly, gait variability measured by standard deviation and coefficient of variation significantly increased at 2 Hz compared to the other conditions. Comparably, kinematic time series analyzed through statistical parametric mapping showed significant adjustments in different portions of the gait cycle at 2 Hz, including increased hip abduction and flexion, greater knee flexion around the heel strike, and augmented ankle dorsiflexion. Participants exhibited gait kinematic variations, mainly at 2 Hz, where the associated mediolateral displacement was higher, as a plausible strategy to maintain stability and postural control during perturbed locomotion. These findings highlight individuals’ complex biomechanical adaptations in response to horizontal WBV, especially at lower frequencies, under dual-task conditions.

Stride length and cerebellar regulation: Key features of early gait disorder in cerebral small vessel disease.

Gait disorder (GD) is a common problem in cerebral small vessel disease (CSVD). This study aimed to determine (1) the early characteristics of GD in CSVD, (2) cerebellar neuroimaging features related to GD in CSVD, and (3) the association of cognitive impairment with GD. In total, 183 subjects were enrolled in this study: patients with CSVD with normal cognitive function (CSVD-NC) group (64 subjects), patients with CSVD with mild cognitive impairment (CSVD-MCI) group (66 subjects), and a healthy control (HC) group (53 subjects). The GD patterns were evaluated using the ReadyGo three-dimensional motion balance testing system. Meanwhile, we analyzed the cerebrum and cerebellum structurally and functionally. Correlation analyses were conducted among gait indicators, neuroimaging features, and neuropsychological tests. Both the CSVD-NC and CSVD-MCI groups had a reduced stride length, cortical atrophy in the left cerebellum VIIIb, and decreased functional connectivity between the left cerebellum VIIIb and left SFGmed compared with the HC group. In the correlation analysis, the gray matter probability of the left cerebellum VIIIb was closely related to stride length in the HC group. In the CSVD-MCI group, linguistic function, memory, and attention were significantly correlated with gait performance. Decreased stride length was the earliest characteristic of GD in CSVD. Structural and functional regulation of the left cerebellum VIIIb could play a particularly important role in early GD in CSVD.

Laser-light cueing shoes with integrated foot pressure and inertial sensing for investigating the impact of visual cueing on gait characteristics in Parkinson's disease individuals.

Gait disorders are a fundamental challenge in Parkinson's disease (PD). The use of laser-light visual cues emitted from shoes has demonstrated effective in improving freezing of gait within less restrictive environments. However, the effectiveness of shoes-based laser-light cueing may vary among individuals with PD who have different types of impairments. We introduced an innovative laser-light visual shoes system capable of producing alternating visual cues for the left and right feet through one-side cueing at a time, while simultaneously recording foot inertial data and foot pressures. The effects of this visual cueing system on gait patterns were assessed in individuals with PD, both those with well-gait and those with worse-gait. Our device successfully quantified gait characteristics, including the asymmetry in the center of pressure trajectory, in individuals with PD. Furthermore, visual cueing prolonged stride times and increased the percentage of stance phase, while concurrently reducing stride length in PD individuals with well-gait. Conversely, in PD individuals with worse-gait, visual cueing resulted in a decreased freeze index and a reduction in the proportion of intervals prone to freezing episodes. The effects of visual cueing varied between PD individuals with well-gait and those with worse-gait. Visual cueing slowed down gait in the well-gait group while it appeared to mitigate freezing episodes in worse-gait group. Future researches, including enhancements to extend the projection distance of visual cues and clinical assessments conducted in real-world settings, will help establish the clinical utility of our proposed visual cueing system.

Development and Adaptive Assistance Control of the Robotic Hip Exoskeleton to Improve Gait Symmetry and Restore Normal Gait

Neurological disorders and aging induce abnormal gait kinematics such as asymmetric gait, reduced stride length, and walking speeds. Gait asymmetry increases musculoskeletal pain and joint impairment in the affected leg, increases the risk of patients falling, and induces higher energy expenditure. This paper presents a novel assistive control framework for the series elastic actuator-driven robotic hip exoskeleton that improves gait symmetry and restores normal gait. The proposed assistive control depends on virtual stiffness compensation with a series elastic actuator (SEA)-driven hip exoskeleton to assist without needing estimation, prediction of the gait phase, or human intent. In addition, adaptive adjustment of the virtual stiffness based on the approximate dynamic programming method is used to improve gait symmetry. The proposed control strategy is successfully implemented, and experiments are validated with human subjects’ gait assistance using a SEA-driven wearable hip exoskeleton. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —This paper was motivated by the problem of hip exoskeleton assistive control. The goal of hip exoskeleton assistance is to improve gait symmetry and restore the normal gait of the patient with neurological disorders and the elderly. Existing approaches to fixturing such parts generally need to estimate or predict the gait phase or human intent. And the existing approaches generally adopted fixed control parameters. The hip exoskeleton’s assistance cannot adapt to various walking conditions and human gait differences. The proposed assistive control is based on virtual stiffness compensation with a SEA-driven hip exoskeleton to assist with walking under various walking conditions without estimating or predicting the gait phase or human intent. And the proposed method is online adjusted control parameters with human-in-the-loop to improve the gait symmetry. The human walking experiment results showed that the hip exoskeleton assistive controller not only reduced muscle activation and human effort but also improved the interjoint coordination of the impaired joint online. We also showed how the assistance controller changes the control parameters according to the gait symmetry with a human-in-the-loop strategy.

Clinical gait analysis in older children with autism spectrum disorder

Individuals with autism spectrum disorder (ASD) often exhibit motor deficits that increase their risk of falls. There is a lack of understanding regarding gait biomechanics demonstrated by older children with ASD. The purpose of the study was to determine differences in gait patterns between older children with ASD and typically developing children. Eleven children with ASD and 11 age- and gender-matched typically developing children were recruited for the study. Participants walked on a force-instrumented treadmill at a constant speed (1.1 ​m/s ​- ​1.2 ​m/s) for five minutes (min). Participants performed maximal voluntary contractions to assess their knee muscular strength. Differences between individuals with ASD and matched control participants were examined through paired t-tests with a significance level of p ​≤ ​0.05. Individuals with ASD demonstrated a smaller knee extensor torque compared to controls (p ​= ​0.002). Participants with ASD exhibited a shorter stride length (p ​= ​0.04), a greater cadence (p ​= ​0.03), and a higher variation in stride width (p ​= ​0.04) compared to control participants. The individuals with ASD experienced a greater braking ground reaction force (p ​= ​0.03) during loading response. The results indicate older children with ASD develop a unique gait pattern signified by a reduced stride length, increased cadence, and an increase of variation in stride width. This unique gait pattern may represent a movement strategy used by the individuals with ASD to compensate for the weakness associated with their knee extensor muscles. Individuals with ASD who demonstrate these unique gait deviations may face reduced postural stability and an increased risk of fall-related injuries.

Effect of stride length on the running biomechanics of healthy women of different statures.

Tibial stress fracture is a debilitating musculoskeletal injury that diminishes the physical performance of individuals who engage in high-volume running, including Service members during basic combat training (BCT) and recreational athletes. While several studies have shown that reducing stride length decreases musculoskeletal loads and the potential risk of tibial injury, we do not know whether stride-length reduction affects individuals of varying stature differently. We investigated the effects of reducing the running stride length on the biomechanics of the lower extremity of young, healthy women of different statures. Using individualized musculoskeletal and finite-element models of women of short (N = 6), medium (N = 7), and tall (N = 7) statures, we computed the joint kinematics and kinetics at the lower extremity and tibial strain for each participant as they ran on a treadmill at 3.0m/s with their preferred stride length and with a stride length reduced by 10%. Using a probabilistic model, we estimated the stress-fracture risk for running regimens representative of U.S. Army Soldiers during BCT and recreational athletes training for a marathon. When study participants reduced their stride length by 10%, the joint kinetics, kinematics, tibial strain, and stress-fracture risk were not significantly different among the three stature groups. Compared to the preferred stride length, a 10% reduction in stride length significantly decreased peak hip (p = 0.002) and knee (p < 0.001) flexion angles during the stance phase. In addition, it significantly decreased the peak hip adduction (p = 0.013), hip internal rotation (p = 0.004), knee extension (p = 0.012), and ankle plantar flexion (p = 0.026) moments, as well as the hip, knee, and ankle joint reaction forces (p < 0.001) and tibial strain (p < 0.001). Finally, for the simulated regimens, reducing the stride length decreased the relative risk of stress fracture by as much as 96%. Our results show that reducing stride length by 10% decreases musculoskeletal loads, tibial strain, and stress-fracture risk, regardless of stature. We also observed large between-subject variability, which supports the development of individualized training strategies to decrease the incidence of stress fracture.

Reliability and Validity of the 10-Meter Walk Test (10MWT) in Adolescents and Young Adults with Down Syndrome.

People with Down syndrome (DS) have gait deficits because motor milestones are usually reached later. Decreased gait speed or reduced stride length are some of the main deficits. The main objective of the present work was to assess the reliability of the 10-Meter Walk Test (10MWT) in adolescents and young adults with DS. The objective has been to analyze the construct validity of the 10MWT with the Timed up and go (TUG) test. A total of 33 participants with DS were included. Reliability was verified by intraclass correlation coefficient (ICC). The agreement was analyzed by the Bland-Altman method. Finally, construct validity was evaluated through Pearson correlation coefficient. The 10MWT intra-rater and inter-rater reliability were good (ICC between 0.76 until 0.9) and excellent (ICC > 0.9), respectively. The minimal detectable change for intra-rater reliability was 0.188 m/s. Also, it has demonstrated moderate construct validity (r > 0.5) considering the TUG test. The 10MWT has shown high intra- and inter-rater reliability and validity in adolescent and adults with SD and a moderate construct validity between TUG test and 10MWT.

Does GERAS DANCE improve gait in older adults?

BackgroundOlder adults at increased fall risk walk slower with less rhythm and coordination. This study explored the effect of dance on spatiotemporal gait parameters in older adults. MethodsParticipants (N = 23) in a single-arm trial were enrolled in the 12-week GERAS DANCE program (total dose of 36 h). Gait was assessed at baseline and 12-weeks under two experimental conditions: normal walking or walking while performing serial subtraction by 3. Outcome measures were gait speed, stride length time, double support time, stride length and stride width. Separate two-way repeated measures ANOVAs were used to determine estimates of the magnitude of effect of GERAS DANCE on spatiotemporal gait parameters and a paired t-test was used to examine differences in cognitive performance before and after dance. ResultsOlder adults (72.50 ± 7.13 years; 75% female) had excellent attendance (82.73% adherence). GERAS DANCE resulted in increased gait speed (p<0.001), reduced stride length time (p = 0.034), reduced double support time (p = 0.001), increased stride length (p = 0.003) and marginally reduced stride width (p = 0.064), regardless of the experimental condition. Improvements in walking performance were observed with sustained performance on the serial subtraction task before and after GERAS DANCE. ConclusionsGERAS DANCE may be a safe and feasible program to help improve spatiotemporal gait parameters in older adults with early memory or mobility impairments. Next steps include testing the efficacy for fall prevention to help inform clinical practice guidelines and virtual intervention implementation.

Pedunculopontine Nucleus Dysconnectivity Correlates With Gait Impairment in Parkinson's Disease: An Exploratory Study.

BackgroundGait impairment is a debilitating and progressive feature of Parkinson’s disease (PD). Increasing evidence suggests that gait control is partly mediated by cholinergic signaling from the pedunculopontine nucleus (PPN).ObjectiveWe investigated whether PPN structural connectivity correlated with quantitative gait measures in PD.MethodsTwenty PD patients and 15 controls underwent diffusion tensor imaging to quantify structural connectivity of the PPN. Whole brain analysis using tract-based spatial statistics and probabilistic tractography were performed using the PPN as a seed region of interest for cortical and subcortical target structures. Gait metrics were recorded in subjects’ medication ON and OFF states, and were used to determine if specific features of gait dysfunction in PD were related to PPN structural connectivity.ResultsTract-based spatial statistics revealed reduced structural connectivity involving the corpus callosum and right superior corona radiata, but did not correlate with gait measures. Abnormalities in PPN structural connectivity in PD were lateralized to the right hemisphere, with pathways involving the right caudate nucleus, amygdala, pre-supplementary motor area, and primary somatosensory cortex. Altered connectivity of the right PPN-caudate nucleus was associated with worsened cadence, stride time, and velocity while in the ON state; altered connectivity of the right PPN-amygdala was associated with reduced stride length in the OFF state.ConclusionOur exploratory analysis detects a potential correlation between gait dysfunction in PD and a characteristic pattern of connectivity deficits in the PPN network involving the right caudate nucleus and amygdala, which may be investigated in future larger studies.

Suppression of Axial Tremor by Deep Brain Stimulation in Patients with Essential Tremor: Effects on Gait and Balance Measures.

Background:Deep brain stimulation (DBS) of the ventralis intermedius (VIM) nucleus of the thalamus has been successful in mitigating upper limb tremor, but the effect on gait and balance performance is unclear. Here, we aim to examine the effectiveness of VIM DBS on stride length variability, sway path length, and task-relevant tremor of various body segments in essential tremor (ET).Methods:Seventeen ET individuals treated with DBS (ET DBS) and 17 age-and sex-matched healthy controls (HC) performed a postural balance and overground walking task. In separate and consecutive visits, ET DBS performed gait and balance tasks with DBS ON or OFF. The main outcome measures were sway path length, stride length variability, and tremor quantified from upper limb, lower limb, upper and lower trunk (axial) during the gait and balance tasks.Results:With DBS OFF, ET DBS exhibited significantly greater stride length variability, sway path length, and tremor during gait and balance task relative to HC. Relative to DBS OFF, DBS ON reduced stride length variability and sway path length in ET DBS. The DBS-induced reduction in stride length variability was associated with the reduction in both upper trunk tremor and upper limb tremor. The DBS-induced reduction in sway path length was associated with the reduction in upper trunk tremor.Discussion:The findings of this study revealed that VIM DBS was effective in improving gait and balance in ET DBS and that improvements in gait and postural balance were associated with a reduction of axial tremor during the tasks.Highlights:ET patients exhibit tremor in various body locations during gait and balance.DBS reduced stride length variability and sway path length.DBS-induced improvements in gait and balance were associated with reduction in axial tremor.

Network-Based Transcranial Direct Current Stimulation May Modulate Gait Variability in Young Healthy Adults.

PurposePrevious studies have linked gait variability to resting-state functional connectivity between the dorsal attention network (DAN) and the default network (DN) in the brain. The purpose of this study was to examine the effects of a novel transcranial direct current stimulation (tDCS) paradigm designed to simultaneously facilitate the excitability of the DAN and suppress the excitability of the DN (i.e., DAN+/DN-tDCS) on gait variability and other gait characteristics in young healthy adults.MethodsIn this double-blinded randomized and sham-controlled study, 48 healthy adults aged 22 ± 2 years received one 20-min session of DAN+/DN-tDCS (n = 24) or no stimulation (the Sham group, n = 24). Immediately before and after stimulation, participants completed a gait assessment under three conditions: walking at self-selected speed (i.e., normal walking), walking as fast as possible (i.e., fast walking), and walking while counting backward (i.e., dual-task walking). Primary outcomes included gait stride time variability and gait stride length variability in normal walking conditions. Secondary outcomes include gait stride time and length variability in fast and dual-task conditions, and other gait metrics derived from the three walking conditions.ResultsCompared to the Sham group, DAN+/DN-tDCS reduced stride length variability in normal and fast walking conditions, double-limb support time variability in fast and dual-task walking conditions, and step width variability in fast walking conditions. In contrast, DAN+/DN-tDCS did not alter average gait speed or the average value of any other gait metrics as compared to the sham group.ConclusionIn healthy young adults, a single exposure to tDCS designed to simultaneously modulate DAN and DN excitability reduced gait variability, yet did not alter gait speed or other average gait metrics, when tested just after stimulation. These results suggest that gait variability may be uniquely regulated by these spatially-distinct yet functionally-connected cortical networks. These results warrant additional research on the short- and longer-term effects of this type of network-based tDCS on the cortical control of walking in younger and older populations.

Quantitative assessment of training effects using EksoGT® exoskeleton in Parkinson's disease patients: A randomized single blind clinical trial

BackgroundGait alterations are among the most disabling motor-symptoms associated with Parkinson's Disease (PD): reduced stride length, stride velocity and lower limb joint range of motion are hallmarks of parkinsonian gait. Research focusing on optimal functional rehabilitation methods has been directed towards powered lower-limb exoskeletons which combines the advantages delivered from the grounded robotic devices with the ability to train the patient in a real-world environment. As gait involves both central (CNS) and peripheral nervous systems (PNS), targeted rehabilitation must restore not only mechanics but also neurophysiological gait patterns. MethodsTwo cohorts of subjects will be enrolled and equally distributed between one group (n = 25) who will undergo a functional kinematic therapy, and one group (n = 25) who will undergo an overground wearable-exoskeleton training. Participants are evaluated at three time points: before the therapy (T0), after the therapy (T1), 4-weeks after T1 (T2). Comprehensive gait analysis and surface electromyography will be combined into neuromusculoskeletal modelling to determine modifications at the PNS level. Functional magnetic resonance imaging coupled with electroencephalography will be used to determine modifications at the CNS level. ConclusionThe findings of the proposed trial will likely give substantial solutions for the management of gait and postural disorders in PD where valid interventions are lacking. The coupling of movement evaluation, which assesses neuromuscular and biomechanical features, with neurological data, will better define the impact of the therapy on the relationship between PD motor alterations and brain activity. This will provide an active treatment that is personalized and shared to large populations.

A Fully-Immersive Virtual Reality Setup to Study Gait Modulation.

Objective: Gait adaptation to environmental challenges is fundamental for independent and safe community ambulation. The possibility of precisely studying gait modulation using standardized protocols of gait analysis closely resembling everyday life scenarios is still an unmet need.Methods: We have developed a fully-immersive virtual reality (VR) environment where subjects have to adjust their walking pattern to avoid collision with a virtual agent (VA) crossing their gait trajectory. We collected kinematic data of 12 healthy young subjects walking in real world (RW) and in the VR environment, both with (VR/A+) and without (VR/A-) the VA perturbation. The VR environment closely resembled the RW scenario of the gait laboratory. To ensure standardization of the obstacle presentation the starting time speed and trajectory of the VA were defined using the kinematics of the participant as detected online during each walking trial.Results: We did not observe kinematic differences between walking in RW and VR/A-, suggesting that our VR environment per se might not induce significant changes in the locomotor pattern. When facing the VA all subjects consistently reduced stride length and velocity while increasing stride duration. Trunk inclination and mediolateral trajectory deviation also facilitated avoidance of the obstacle.Conclusions: This proof-of-concept study shows that our VR/A+ paradigm effectively induced a timely gait modulation in a standardized immersive and realistic scenario. This protocol could be a powerful research tool to study gait modulation and its derangements in relation to aging and clinical conditions.

Clinical Disease Severity Mediates the Relationship between Stride Length and Speed and the Risk of Falling in Parkinson's Disease.

The shuffling gait with slowed speed and reduced stride length has been considered classic clinical features in idiopathic Parkinson’s disease (PD), and the risk of falling increases as the disease progresses. This raises the possibility that clinical disease severity might mediate the relationship between stride length and speed and the risk of falling in patients with PD. Sixty-one patients with PD patients underwent the clinical scores as well as quantitative biomechanical measures during walking cycles before and after dopamine replacement therapy. Mediation analysis tests whether the direct effect of an independent variable (stride length and speed) on a dependent variable (three-step fall prediction model score) can be explained by the indirect influence of the mediating variable (Unified Parkinson’s Disease Rating Scale (UPDRS) total scores). The results demonstrate that decreased stride length, straight walking speed, and turning speed is associated with increased three-step fall prediction model score (r = −0.583, p < 0.0001, r = −0.519, p < 0.0001, and r = −0.462, p < 0.0001, respectively). We further discovered that UPDRS total scores value is negatively correlated with stride length, straight walking, and turning speed (r = −0.651, p < 0.0001, r = −0.555, p < 0.0001, and r = −0.372, p = 0.005, respectively) but positively correlated with the fall prediction model score value (r = 0.527, p < 0.0001). Further mediation analysis shows that the UPDRS total score values serve as mediators between lower stride length, straight walking, and turning speed and higher fall prediction model score values. Our results highlighted the relationship among stride length and speed, clinical disease severity, and risk of falling. As decreased stride length and speed are hallmarks of falls, monitoring the changes of quantitative biomechanical measures along with the use of wearable technology in a longitudinal study can provide a scientific basis for pharmacology, rehabilitation programs, and selecting high-risk candidates for surgical treatment to reduce future fall risk.

Foot and Ankle Motion after Tibiotalocalcaneal Arthrodesis: Comparison with Tibiotalar Arthrodesis Using a Multi-Segment Foot Model.

Tibiotalocalcaneal arthrodesis is an established surgical procedure for treating patients with end-stage ankle joint arthritis and subtalar joint arthritis. Although it greatly relives pain, a major drawback is loss of range of motion. Although it is known to restrict an additional subtalar joint compared to tibiotalar arthrodesis, there is a lack of gait analysis studies comparing the two methods. This study aimed to evaluate the differences in kinematics of the foot and ankle joints between tibiotalar and tibiotalocalcaneal arthrodesis. We also compared preoperative and postoperative statuses for each surgical method. The study included 12 and 9 patients who underwent tibiotalar and tibiotalocalcaneal arthrodesis, respectively, and 40 healthy participants were included in the control group. The DuPont foot model was used to analyze intersegmental foot and ankle kinematics during gait. Compared to controls, both tibiotalar and tibiotalocalcaneal arthrodesis resulted in slow gait speed with reduced stride length, increased step width, and decreased range of sagittal plane motion. Both fusion methods showed similar range of motion in all segments and planes following surgery. Coronal positions showed more supination of the forefoot and pronation of the hindfoot segment after each operation, particularly tibiotalocalcaneal arthrodesis. Gait after tibiotalocalcaneal arthrodesis did not significantly differ from that after tibiotalar arthrodesis, but there was a tendency of more pronation in the hindfoot segment. Both fusion methods limited foot and ankle motion in similar ways. Comparing tibiotalar and tibiotalocalcaneal arthrodesis suggests that additionally fusing the subtalar joint does not cause greater movement restriction in patients. Objectively comparing tibiotalar and tibiotalocalcaneal arthrodesis will facilitate further understanding of the effect of tibiotalocalcaneal arthrodesis on movement and the value of subtalar joint motion for improved preoperative counselling.

Comparison of Spatiotemporal Parameters between Athletes and Non-Athletes at Upslope Running

Upslope locomotion is challenging in our day to day life for which neuromuscular system have to work extraordinarily [1]. Despite increasing popularity of trail running, trekking, hiking that include various slope inclination, the majority of running biomechanics studies have only considered level running [2]. To understand the control of human locomotion better, physiological and biomechanical variables related to incremental slopes running during the gait cycle is imperative. Several studies have examined upslope running but the results are inconclusive [2-6]. Running at higher upslope inclination showed higher step frequency [2] and reduced stride length [6]. Conversely some studies examining various parameters did not observe any difference between level and uphill running at constant speed [4,7]. Previous studies comparing spatiotemporal characteristics in varying level of trained runners [5,8-10] indicated longer flight time and better adaptation in elite runners compared to amateur runners with increased inclination [5]. Conversely, a study showed no difference in adaptation of spatiotemporal characteristics between amateur and highly trained athletes while running upslope at given speed [2]. This leaves questions whether non-athletes adapt to different slopes gradient in the same way as trained athletes. We aimed to determine the effect of different slope gradients on spatiotemporal gait parameters between athletes and non-athletes during running on an instrumented treadmill.

Biomechanical responses of Nordic walking in people with Parkinson's disease.

In healthy adults, Nordic walking (NW) is known to increase the external mechanical energy fluctuations, though the external work is unaltered due to an improved pendulum-like recovery in comparison with free walking (FW). We aimed to compare mechanical, pendulum-like, and spatiotemporal parameters of gait at different speeds with and without NW poles in people with Parkinson's disease and healthy controls. The study included 11 people (aged 65.6±7.0years) with idiopathic Parkinson's disease, scoring between 1 and 1.5 on the Hoehn and Yahr scale (H&Y), and nine healthy controls (aged 70.0±5.6years). All the people were experienced Nordic walkers. Walking tests were performed at 1.8kmh-1 and 4.7kmh-1 , on eight 3D force platforms on a walkway. We found greater pendulum-like energy recovery (p<0.05) in the Parkinson group during NW than in FW, while external mechanical work remained similar (p>0.05). People with Parkinson's disease showed a major increase in vertical and forward energy fluctuations using poles than in healthy controls. In addition, the Parkinson group showed increased stride frequency and reduced stride length compared to controls in the NW and FW conditions. Our findings partly justify the lower walking economy in Parkinson's disease due to reduced pendulum-like mechanism at commonly used speeds. NW alters gait mechanics similarly in Parkinson group and healthy control, increasing the total mechanical work. Therefore, NW can be a compelling strategy for rehabilitation because of its potential for improving functional mobility, increasing pendulum-like mechanism in Parkinson's disease.

Design and Validation of a Smartphone-based Haptic Feedback System for Gait Training

This letter presents a novel vibrotactile haptic system controlled by a smartphone that can be used for gait training of older adults. Compared to previous works, the system's modularity as well as its smartphone-based controller and user interface can enhance its usability and promote regular gait training of users during their daily living. Given the prevalence of reduced stride length and speed in older adults, we developed a biomechanical data-driven approach to enable improving those outcomes via modifying their underlying surrogates. A subject study was performed by recruiting 12 young participants (19-39 years) to assess the efficacy of the haptic system and our approach based on biomechanical surrogates. It was found that the participants could significantly increase their thigh and shank extensions (i.e., the surrogates) via the feedback provided by our system, and those increases resulted in higher values of their stride length and walking speed. The results provide a clear proof-of-concept for the developed biomechanics-driven haptic system for gait training of older adults to potentially improve their mobility and living independence.