Walking and balance in older adults with age-related hearing loss: A cross-sectional study of cases and matched controls.

BACKGROUND: Hearing loss (HL) is prevalent in older individuals. It is suggested that there is an association between age-related HL, walking and balance, leading to poorer function and increased risk of falls in older individuals. RESEARCH QUESTION: Is HL associated with physical performance, gait variability, and postural sway in older adults, and will additional dizziness moderate the effect of HL on balance? METHODS: In this cross-sectional study we examined 100 older individuals (age ≥70 years, 60 % females), divided in two groups, with or without age-related HL. Physical function and balance were evaluated by the Short Physical Performance Battery (SPPB), postural sway measured on a force platform (posturography), and balance in walking (gait variability) measured with a body-worn sensor. Multiple linear regression was used to examine the relationships between the variables, with physical function and balance as outcomes and HL as a dichotomous exposure (>30 dB). For all analyses, we further tested if associations were modified by self-reported dizziness. RESULTS: Multiple regression analysis with HL, age, sex, education, diabetes, and cardiovascular disease revealed a significant association between reduced SPPB and HL. Multiple linear regression analysis also showed that HL was associated with increased postural sway on firm surface with eyes open and closed after adjusting for age, sex, education, diabetes, and cardiovascular disease. There was significant association between HL and increased gait variability during dual task walking in all directions after adjusting for age, sex, education, diabetes, and cardiovascular disease. Further, we found that the association between HL and SPPB was significantly stronger in those with dizziness compared with those without dizziness. Dizziness also modified the association of HL with the other SPPB sub-scores but not for the other outcomes of postural sway or gait variability. SIGNIFICANCE: In this study, age-related HL was associated with worse physical performance as measured by SPPB, postural sway, and gait variability. This relationship illustrates the importance of assessing physical performance in people with HL to prevent risk of falls and disability.

The plurality of mechanisms of gait initiation disorders in Parkinson's disease: Relationships with motor, cognitive and limbic functions.

BACKGROUND: Deficient postural adaptation and freezing lead to gait initiation abnormalities in Parkinson's disease. Gait initiation is characterized by longer motor preparation, which is a marker of increased risk of falling, and by abnormal postural adjustments. Better understanding the nature of these motor preparation disturbances will enable us to adapt rehabilitation and reduce falls. RESEARCH QUESTION: Our objective was to describe the different components (in the motor, cognitive and limbic domains) of gait initiation parameters in Parkinson's disease. METHODS: Forty-four patients with Parkinson's disease performed repeated step initiations under high attentional load with decision-making. The proportions of multiple anticipatory postural adjustments and anticipatory postural adjustment errors, markers of abnormal motor preparation, were measured. A logistic regression analysis studied the relationships between step initiation perturbations and the demographic, motor, cognitive, and neuropsychiatric characteristics of the patients. RESULTS: Multiple anticipatory postural adjustments and anticipatory postural adjustments errors lengthened step execution time. Motor severity explained the multiple anticipatory postural adjustments, suggesting a pathological role. Attentional performance explained anticipatory postural adjustments errors. Demographic and neuropsychiatric characteristics didn't contribute significantly to the abnormal anticipatory postural adjustments. SIGNIFICANCE: Motor disability contributes to the delay in step execution in Parkinson's disease through multiple anticipatory postural adjustments, highlighting the need to target motor preparation improvement in rehabilitation.

A usability study on the inGAIT-VSO: effects of a variable-stiffness ankle-foot orthosis on the walking performance of children with cerebral palsy.

BACKGROUND: Ankle-foot orthoses (AFOs) are commonly used by children with cerebral palsy (CP), but traditional solutions are unable to address the heterogeneity and evolving needs amongst children with CP. One key limitation lies in the inability of current passive devices to customize the torque-angle relationship, which is essential to adapt the support to the specific individual needs. Powered alternatives can provide customized behavior, but often face challenges with reliability, weight, and cost. Overall, clinicians find certain barriers that hinder their prescription. In recent work, the Variable Stiffness Orthosis (VSO) was developed, enabling stiffness customization without the need for motors or sophisticated control. METHODS: This work evaluates a pediatric version of the VSO (inGAIT-VSO) by investigating its impact on the walking performance of children with CP and its potential to be used as a tool for assessing the effect of variable stiffness on pathological gait. Data was collected for three typical developing (TD) children and six pediatric participants with CP over two sessions involving walking/balance tasks and questionnaires. RESULTS: The sensors of the inGAIT-VSO provided useful information to assess the impact of the device. Increasing the stiffness of the inGAIT-VSO significantly reduced participants' dorsiflexion and plantarflexion. Despite reduced range of motion, the peak restoring torque increased with stiffness. Overall the participants' gait pattern was altered by reducing crouch gait, preventing drop-foot and supporting body weight. Participants with CP exhibited significantly lower (p < 0.05) physiological cost when walking with the inGAIT-VSO compared to normal condition (own AFO or shoes only). Generally, the device did not impair walking and balance of the participants compared to normal conditions. According to the questionnaire results, the inGAIT-VSO was easy to use and participants reported positive experiences. CONCLUSION: The inGAIT-VSO stiffnesses significantly affected participants' plantarflexion and dorsiflexion and yielded objective data regarding walking performance in pathological gait (e.g. ankle angle, exerted torque and restored assistive energy). These effects were captured by the sensors integrated in the device without using external equipment. The inGAIT-VSO shows promise for customizing AFO stiffness and aiding clinicians in selecting a personalized stiffness based on objective metrics.

Muscle activation patterns and gait changes in unilateral knee osteoarthritis patients: a comparative study with healthy controls.

The objective of this study was to investigate the differences in muscle activation and kinematic parameters between patients with unilateral knee osteoarthritis (OA) and healthy individuals. Additionally, the study aimed to determine the correlation between muscle activation and kinematic parameters with knee OA symptoms. Participants with unilateral knee OA (n = 32) and healthy individuals (n = 32) completed the gait test. Electromyography (EMG) and motion capture were employed to collect muscle activation data and kinematic parameters. Spearman's correlation coefficient was used to analysis the correlation between BMI, symptomatic side EMG parameters, kinematic parameters, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. Furthermore, a multiple linear regression analysis of WOMAC pain was also conducted. The peak root mean square, integrated electromyography, and co-activation index (CCI) were increased bilaterally in the unilateral knee OA group compared to the healthy group. Furthermore, these values were higher on the symptomatic side than on the asymptomatic side. Compared with the healthy group, the knee OA group had lower gait speed, decreased stride length and cadence on bilateral sides, longer total stance time and double-stance time, and shorter single stance time and swing time. The maximum knee flexion angle of the swing phase on the symptomatic side of the knee OA group was smaller than that on the asymptomatic side and healthy group. Changes in EMG and gait parameters on the symptomatic side correlated with WOMAC scores. The main factors influencing WOMAC pain were the CCI values of the lateral femoral and biceps femoris muscles and gait speed. Muscle activation and kinematic parameters in the lower limbs of patients with unilateral knee OA were altered bilaterally during walking. These alterations on the symptomatic side were associated with knee OA-related pain. ChiCTR2200064958. Date of registration: 2022-10-24. Key Points • Unilateral symptomatic knee OA leads to bilateral alterations in muscle activation and gait parameters. • Symptomatic muscle activation and gait parameter changes in knee OA patients are associated with knee OA symptoms. • Correcting abnormal muscle activation conditions and gait training may reduce knee OA-related pain.

EFFECTS OF TREADMILL GAIT TRAINING ON BALANCE IN PARKINSON'S PATIENTS AFTER DEEP BRAIN STIMULATION.

Objective: After deep brain stimulation (DBS), patients with Parkinson's disease (PD) typically still present significant gait and postural stability problems, and thus additional interventions are needed. In this way, our purpose was evaluate the comparative effectiveness of treadmill training, with and without body weight support, on balance outcomes among patients with PD after DBS. Methods: Eleven patients with PD that were using bilateral subthalamic nucleus DBS were evaluated using Time Up and Go test (TUG); Berg Balance Scale (BBS) and Static Posturography. In phase 1, all subjects participated in 8-weeks of treadmill training in conjunction with conventional physiotherapy. After six weeks (wash-out), each patient then participated in a subsequent 8-weeks of treadmill training with partial body weight support. Results: After the phase 1, there were improvements on the cognitive TUG performance (Before: 15.7 ± 1,8 sec; After: 13.7 ± 3.1 sec; p < 0.01) and an increase of anteroposterior and medio-lateral body oscillation with eyes closed. After the phase 2, there were improvements in conventional (Before: 12.3 ± 2.0 sec; After: 10.7 ± 1.7 sec; p < 0.01) and cognitive (Before: 14.6 ± 3.5 sec; After: 12.5 ± 1.6 sec; p < 0.05) TUG performances. There were no significant changes in the Berg Balance Scale following either training protocol. Conclusion: Both trainings improved static and dynamic balance and had similar results; however, supported treadmill training seemed to be a potentially superior option, as patients tended to feel safer. Level of Evidence II, therapeutic studies - investigation of treatment outcomes.

Objetivo: Mesmo após a estimulação cerebral profunda (ECP), os pacientes com doença de Parkinson (DP) muitas vezes ainda apresentam problemas significativos de marcha e estabilidade postural, e, portanto, intervenções adicionais são necessárias. Avaliar a eficácia comparativa do treinamento em esteira, com e sem suporte de peso corporal, nos resultados de equilíbrio de pacientes com DP após ECP. Métodos: Onze pacientes com DP em uso de ECP bilateral do núcleo subtalâmico foram avaliados pelos testes Time Up and Go (TUG), escala de equilíbrio de Berg (EEB) e posturografia estática. Na fase 1, todos participaram de oito semanas de treinamento em esteira em conjunto com fisioterapia convencional. Após seis semanas (wash-out), cada paciente participou de oito semanas subsequentes de treinamento em esteira com suporte parcial de peso corporal. Resultados: Depois da fase 1, houve melhora no desempenho cognitivo do TUG (antes: 15,7 ± 1,8 s; depois: 13,7 ± 3,1 s; p < 0,01) e aumento da oscilação anteroposterior e médio-lateral do corpo com os olhos fechados. Após a fase 2, os resultados do TUG convencional (antes: 12,3 ± 2,0 seg; depois: 10,7 ± 1,7 seg; p < 0,01) e cognitivo (antes: 14,6 ± 3,5 s; depois: 12,5 ± 1,6 s; p < 0,05) demonstraram melhora. Os protocolos de treinamento não causaram mudanças significativas na EEB.. Conclusão: Ambos os treinos melhoraram o equilíbrio estático e dinâmico e tiveram resultados semelhantes; no entanto, o treinamento em esteira com suporte é uma opção potencialmente superior, uma vez que os pacientes tendiam a se sentir mais seguros. Nível de Evidência II, estudos terapêuticos - investigação de resultados de tratamento.

Detection of freezing of gait in Parkinson's disease from foot-pressure sensing insoles using a temporal convolutional neural network.

Backgrounds: Freezing of gait (FoG) is a common and debilitating symptom of Parkinson's disease (PD) that can lead to falls and reduced quality of life. Wearable sensors have been used to detect FoG, but current methods have limitations in accuracy and practicality. In this paper, we aimed to develop a deep learning model using pressure sensor data from wearable insoles to accurately detect FoG in PD patients. Methods: We recruited 14 PD patients and collected data from multiple trials of a standardized walking test using the Pedar insole system. We proposed temporal convolutional neural network (TCNN) and applied rigorous data filtering and selective participant inclusion criteria to ensure the integrity of the dataset. We mapped the sensor data to a structured matrix and normalized it for input into our TCNN. We used a train-test split to evaluate the performance of the model. Results: We found that TCNN model achieved the highest accuracy, precision, sensitivity, specificity, and F1 score for FoG detection compared to other models. The TCNN model also showed good performance in detecting FoG episodes, even in various types of sensor noise situations. Conclusions: We demonstrated the potential of using wearable pressure sensors and machine learning models for FoG detection in PD patients. The TCNN model showed promising results and could be used in future studies to develop a real-time FoG detection system to improve PD patients' safety and quality of life. Additionally, our noise impact analysis identifies critical sensor locations, suggesting potential for reducing sensor numbers.

Vibrotactile Foot Device for Freezing of Gait in Parkinson's Disease: A Pilot Study.

BACKGROUND: Vibrotactile stimulation has been studied in its efficacy of reducing freezing of gait (FOG) in patients with Parkinson's disease (PD). However, the results are still controversial. We evaluated the efficacy of a newly developed vibrotactile foot device on freezing severity and gait measures in PD patients with FOG. OBJECTIVE: To evaluate the efficacy of vibrotactile foot device on PD patients with FOG. METHODS: Thirty-three PD patients with FOG were examined during their "off" medication state. The efficacy of the vibrotactile foot device was evaluated using a gait protocol comprising walking trials with vibrotactile stimulation "off" and "on." Walking trials were videotaped for the offline rating by two movement disorder specialists. The Opal inertial sensor unit (128 Hz; Mobility Lab; APDM Inc., Portland, OR, USA) was used for quantitative gait analysis. RESULTS: The results demonstrated 33.1% reduction in number of FOG episodes (P < 0.001) and 32.6% reduction of freezing episodes (P < 0.001). Quantitative gait analysis showed a significant increase in step length (P = 0.033). A moderate negative correlation was observed between the change of percent time frozen and age (r = -0.415, P = 0.016). 73% of participants reported minimal to substantial improvement in walking with this vibrating stimulation delivered by the vibrotactile foot device. CONCLUSIONS: The vibrotactile foot device is an efficient device that could significantly reduce freezing severity and provide gait regulation to patients with PD experiencing frequent freezing. It could potentially be used in the home environment for improving the quality of life.

Extraction and Validation of Biomechanical Gait Parameters with Contactless FMCW Radar.

A 77 GHz frequency-modulated continuous wave (FMCW) radar was utilized to extract biomechanical parameters for gait analysis in indoor scenarios. By preprocessing the collected raw radar data and eliminating environmental noise, a range-velocity-time (RVT) data cube encompassing the subjects' information was derived. The strongest signals from the torso in the velocity and range dimensions and the enveloped signal from the toe in the velocity dimension were individually separated for the gait parameters extraction. Then, six gait parameters, including step time, stride time, step length, stride length, torso velocity, and toe velocity, were measured. In addition, the Qualisys system was concurrently utilized to measure the gait parameters of the subjects as the ground truth. The reliability of the parameters extracted by the radar was validated through the application of the Wilcoxon test, the intraclass correlation coefficient (ICC) value, and Bland-Altman plots. The average errors of the gait parameters in the time, range, and velocity dimensions were less than 0.004 s, 0.002 m, and 0.045 m/s, respectively. This non-contact radar modality promises to be employable for gait monitoring and analysis of the elderly at home.

Cautious Gait during Navigational Tasks in People with Hemiparesis: An Observational Study.

Locomotor and balance disorders are major limitations for subjects with hemiparesis. The Timed Up and Go (TUG) test is a complex navigational task involving oriented walking and obstacle circumvention. We hypothesized that subjects with hemiparesis adopt a cautious gait during complex locomotor tasks. The primary aim was to compare spatio-temporal gait parameters, indicators of cautious gait, between the locomotor subtasks of the TUG (Go, Turn, Return) and a Straight-line walk in people with hemiparesis. Our secondary aim was to analyze the relationships between TUG performance and balance measures, compare spatio-temporal gait parameters between fallers and non-fallers, and identify the biomechanical determinants of TUG performance. Biomechanical parameters during the TUG and Straight-line walk were analyzed using a motion capture system. A repeated measures ANOVA and two stepwise ascending multiple regressions (with performance variables and biomechanical variables) were conducted. Gait speed, step length, and % single support phase (SSP) of the 29 participants were reduced during Turn compared to Go and Return and the Straight-line walk, and step width and % double support phase were increased. TUG performance was related to several balance measures. Turn performance (R2 = 63%) and Turn trajectory deviation followed by % SSP on the paretic side and the vertical center of mass velocity during Go (R2 = 71%) determined TUG performance time. People with hemiparesis adopt a cautious gait during complex navigation at the expense of performance.

Impacts of Wearable Resistance Placement on Running Efficiency Assessed by Wearable Sensors: A Pilot Study.

Wearable resistance training is widely applied to enhance running performance, but how different placements of wearable resistance across various body parts influence running efficiency remains unclear. This study aimed to explore the impacts of wearable resistance placement on running efficiency by comparing five running conditions: no load, and an additional 10% load of individual body mass on the trunk, forearms, lower legs, and a combination of these areas. Running efficiency was assessed through biomechanical (spatiotemporal, kinematic, and kinetic) variables using acceleration-based wearable sensors placed on the shoes of 15 recreational male runners (20.3 ± 1.23 years) during treadmill running in a randomized order. The main findings indicate distinct effects of different load distributions on specific spatiotemporal variables (contact time, flight time, and flight ratio, p ≤ 0.001) and kinematic variables (footstrike type, p < 0.001). Specifically, adding loads to the lower legs produces effects similar to running with no load: shorter contact time, longer flight time, and a higher flight ratio compared to other load conditions. Moreover, lower leg loads result in a forefoot strike, unlike the midfoot strike seen in other conditions. These findings suggest that lower leg loads enhance running efficiency more than loads on other parts of the body.

Prediction of Freezing of Gait in Parkinson's disease based on multi-channel time-series neural network.

Freezing of Gait (FOG) is a noticeable symptom of Parkinson's disease, like being stuck in place and increasing the risk of falls. The wearable multi-channel sensor system is an efficient method to predict and monitor the FOG, thus warning the wearer to avoid falls and improving the quality of life. However, the existing approaches for the prediction of FOG mainly focus on a single sensor system and cannot handle the interference between multi-channel wearable sensors. Hence, we propose a novel multi-channel time-series neural network (MCT-Net) approach to merge multi-channel gait features into a comprehensive prediction framework, alerting patients to FOG symptoms in advance. Owing to the causal distributed convolution, MCT-Net is a real-time method available to give optimal prediction earlier and implemented in remote devices. Moreover, intra-channel and inter-channel transformers of MCT-Net extract and integrate different sensor position features into a unified deep learning model. Compared with four other state-of-the-art FOG prediction baselines, the proposed MCT-Net obtains 96.21% in accuracy and 80.46% in F1-score on average 2 s before FOG occurrence, demonstrating the superiority of MCT-Net.

Relationship of total sagittal spinal alignment index of thoracic kyphosis and lumbar lordosis with physical function in community-dwelling older adults.

BACKGROUND: Overall spinal curvature is evaluated by calculating the difference between the angles of lumbar lordosis (LL) and thoracic kyphosis (TK) and is expressed as LL minus TK (LL-TK). It is unclear whether LL-TK is associated with physical function in community-dwelling older adults and whether it is more relevant than TK or LL alone. OBJECTIVE: This study aimed to identify whether LL-TK is associated with physical function in community-dwelling older adults, and whether it is strongly associated than TK or LL alone. METHODS: The participants comprised 1,674 community-dwelling older adults who underwent physical assessments (women, n = 1,099; mean age, 67.4 ± 5.3 years). As spinal alignment indices, TK and LL were measured using skin surface methods, and LL-TK was calculated as the difference between them. Decreased LL-TK indicated increased overall spinal curvature. Physical function was determined by measuring single-leg standing, five-times chair-stand, and usual gait speed. Stepwise multiple regression analyses were performed with each physical function as the dependent variable and spinal alignment indices as the independent variables, with adjustments. RESULTS: Multiple regression analyses showed that single-leg standing (ß = 0.092, 95% confidence interval [CI] = 0.071 to 0.214, p < .001) and five-times chair-stand (ß=-0.142, 95% CI = -0.037 to -0.019, p < .001) were significantly associated with LL-TK, but not LL. Both LL-TK (ß = 0.121, 95% CI = 0.001 to 0.004, p < .001) and LL (ß = 0.087, 95% CI = 0.001 to 0.003, p = .003) were significant determinants of usual gait speed. CONCLUSIONS: This study showed that decreased LL-TK may be associated with poor physical function. This association may be stronger than that observed for TK or LL alone.

Effects of combining rTMs and augmented reality gait adaptive training on walking function of patients with stroke based on three-dimensional gait analysis and sEMG: a randomized controlled trial.

BACKGROUND: Augmented reality gait adaptive training (ARGAT) and repetitive transcranial magnetic stimulation (rTMS) have both demonstrated efficacy in improving lower limb motor function in survivors of stroke. PURPOSE: To investigate the effects of combining rTMS and ARGAT on motor function in survivors of stroke. METHODS: The experimental group received a combination of rTMS and ARGAT, while the control group received ARGAT alone. The interventions comprised a total of 20 sessions, conducted over four weeks with five consecutive daily sessions. Outcome measures included three-dimensional gait analysis (3DGA), surface electromyography (sEMG), Fugl-Meyer assessment for the lower extremity (FMA-LE), and the Berg Balance Scale (BBS). RESULTS: Following the intervention, both groups showed significant improvements in walking speed, symmetry index, affected step length, affected stride length, FMA-LE, and BBS scores (p < .05). Furthermore, the experimental group demonstrated greater improvements in walking speed (F = 4.58, p = .040), cadence (F = 5.67, p = .023), affected step length (F = 5.79, p = .022), affected stride length (F = 4.84, p = .035), FMA-LE (Z = 2.43, p = .019), and BBS (F = 4.76, p = .036) compared to the control group. The experimental group demonstrated a significant improvement in the co-contraction index (CCI) of the knee joint (F = 14.88, p < .001), a change not observed in the control group (F = 2.16, p = .151). However, neither group showed significant alterations in CCI of the ankle joint (F = 1.58, p = .218), step width (F = 0.24, p = .630), unaffected step length (F = 0.22, p = .641), or unaffected stride length (F = 2.99, p = .093). CONCLUSION: The combination of low-frequency rTMS and ARGAT demonstrated superior effects on motor function recovery compared to ARGAT alone in survivors of stroke.

Inter-joint coordination with and without dopaminergic medication in Parkinson's disease: a case-control study.

BACKGROUND: How the joints exactly move and interact and how this reflects PD-related gait abnormalities and the response to dopaminergic treatment is poorly understood. A detailed understanding of these kinematics can inform clinical management and treatment decisions. The aim of the study was to investigate the influence of different gait speeds and medication on/off conditions on inter-joint coordination, as well as kinematic differences throughout the whole gait cycle in well characterized pwPD. METHODS: 29 controls and 29 PD patients during medication on, 8 of them also during medication off walked a straight walking path in slow, preferred and fast walking speeds. Gait data was collected using optical motion capture system. Kinematics of the hip and knee and coordinated hip-knee kinematics were evaluated using Statistical Parametric Mapping (SPM) and cyclograms (angle-angle plots). Values derived from cyclograms were compared using repeated-measures ANOVA for within group, and ttest for between group comparisons. RESULTS: PD gait differed from controls mainly by lower knee range of motion (ROM). Adaptation to gait speed in PD was mainly achieved by increasing hip ROM. Regularity of gait was worse in PD but only during preferred speed. The ratios of different speed cyclograms were smaller in the PD groups. SPM analyses revealed that PD participants had smaller hip and knee angles during the swing phase, and PD participants reached peak hip flexion later than controls. Withdrawal of medication showed an exacerbation of only a few parameters. CONCLUSIONS: Our findings demonstrate the potential of granular kinematic analyses, including > 1 joint, for disease and treatment monitoring in PD. Our approach can be extended to further mobility-limiting conditions and other joint combinations. TRIAL REGISTRATION: The study is registered in the German Clinical Trials Register (DRKS00022998, registered on 04 Sep 2020).

Factors leading to falls in transfemoral prosthesis users: a case series of prosthesis-side stumble recovery responses.

BACKGROUND: Falls due to stumbling are prevalent for transfemoral prosthesis users and may lead to increased injury risk. This preliminary case series analyzes the transfemoral prosthesis user stumble recovery response to highlight key deficits in current commercially-available prostheses and proposes potential interventions to improve recovery outcomes. METHODS: Six transfemoral prosthesis users were perturbed on their prosthetic limb at least three times while walking on a treadmill using obstacle perturbations in early, mid and late swing. Kinematic data were collected to characterize the response, while fall rate and key kinematic recovery metrics were used to assess the quality of recovery and highlight functional deficits in current commercially-available prostheses. RESULTS: Across all participants, 13 (54%) of the 24 trials resulted in a fall (defined as > 50% body-weight support) with all but one participant (83%) falling at least once and two participants (33%) falling every time. In contrast, in a previous study of seven young, unimpaired, non-prosthesis users using the same experimental apparatus, no falls occurred across 190 trials. For the transfemoral prosthesis users, early swing had the highest rate of falling at 64%, followed by mid-swing at 57%, and then late swing at 33%. The trend in falls was mirrored by the kinematic recovery metrics (peak trunk angle, peak trunk angular velocity, forward reach of the perturbed limb, and knee angle at ground contact). In early swing all four metrics were deficient compared to non-prosthesis user controls. In mid swing, all but trunk angular velocity were deficient. In late swing only forward reach was deficient. CONCLUSION: Based on the stumble recovery responses, four potential deficiencies were identified in the response of the knee prostheses: (1) insufficient resistance to stance knee flexion upon ground contact; (2) insufficient swing extension after a perturbation; (3) difficulty initiating swing flexion following a perturbation; and (4) excessive impedance against swing flexion in early swing preventing the potential utilization of the elevating strategy. Each of these issues can potentially be addressed by mechanical or mechatronic changes to prosthetic design to improve quality of recovery and reduce the likelihood a fall.

Prediction of joint moments from kinematics using machine learning in children with congenital talipes equino varus and typically developing peers.

Background: Understanding joint loading and the crucial role of joint moments is essential for developing treatment strategies in gait analysis, which often requires the precise estimation of joint moments through an inverse dynamic approach. This process necessitates the use of a force plate synchronized with a motion capture system. However, effectively capturing ground reaction force in typically developing (TD) children and those with congenital talipes equino varus (CTEV) presents challenges, while the availability and high cost of additional force plates pose additional challenges. Therefore the study aimed to develop, train, and identify the most effective machine learning (ML) model to predict joint moments from kinematics for TD children and those with CTEV. Method: In a study at the Gait Lab, 13 children with bilateral CTEV and 17 TD children underwent gait analysis to measure kinematics and kinetics, using a 12-camera Qualisys Motion Capture System and an AMTI force plate. ML models were then trained to predict joint moments from kinematic data as input. Results: The random forest regressor and deep neural networks (DNN) proved most effective in predicting joint moments from kinematics for TD children, yielding better results. The Random Forest regressor achieved an average r of 0.75 and nRMSE of 23.03 % for TD children, and r of 0.74 and 23.82 % for CTEV. DNN achieved an average r of 0.75 and nRMSE of 22.83 % for TD children, and r of 0.76 and nRMSE of 23.9 % for CTEV. Conclusions: The findings suggest that using machine learning to predict joint moments from kinematics shows moderate potential as an alternative to traditional gait analysis methods for both TD children and those with CTEV. Despite its potential, the current prediction accuracy limitations hinder the immediate clinical application of these techniques for decision-making in a pediatric population.

Biomechanical variations in patients with flatfoot deformity: Impact of gender, age, and BMI on foot kinetics and kinematics.

Background: Flatfoot is considered by the collapse of the foot arch, altered biomechanics and impacting functional abilities. The biomechanical gait alteration of foot kinematics and kinetics in individuals with flatfoot, based on gender, age and Body mass index (BMI) in each cohort is unclear. This study explores how gender, age, and body mass index (BMI) impact distinct foot biomechanical characteristics, including ankle joint angle (Jc°), Ground force reaction angle (GFR°), Achilles tendon force (T), Ankle joint force (Jc) and vertical ground reaction force (VGRF) during the gait stance phase, in flatfoot versus normal-foot individuals on Indian Population. Method: A foot pressure test and sagittal plane motion analysis were performed on 142 individuals with normal-foot arches and 102 with flatfoot, stratified by gender, age, and BMI. Calculations of the magnitude and direction of forces in ankle joint equilibrants relied on inverse dynamic analysis, vertical ground force reaction and mapping motion data of the gait stance phases. Result: In the midstance phase, females with high BMI (HBMI) in the middle and older age group (p = 0.029 and p = 0.014), and males with HBMI in the older age group (p = 0.039) demonstrate significantly higher V G R F . Females and males with HBMI in middle and older age groups, along with males with normal BMI in the older age cohort, show positive and negative ranges of GFR°, indicating gait instability. In the push-off phase, females with HBMI in a middle-aged group exhibit significantly lower T a n d J c (p = 0.023 and p = 0.026) respectively. Conclusion: The biomechanical issues in individuals with flatfoot, while accounting for the influence of gender, age and BMI, are crucial for tailored interventions and precise solutions to biomechanical issues, thereby enhancing foot function and reducing discomfort.

Machine learning model comparison for freezing of gait prediction in advanced Parkinson's disease.

Introduction: Freezing of gait (FOG) is a paroxysmal motor phenomenon that increases in prevalence as Parkinson's disease (PD) progresses. It is associated with a reduced quality of life and an increased risk of falls in this population. Precision-based detection and classification of freezers are critical to developing tailored treatments rooted in kinematic assessments. Methods: This study analyzed instrumented stand-and-walk (SAW) trials from advanced PD patients with STN-DBS. Each patient performed two SAW trials in their OFF Medication-OFF DBS state. For each trial, gait summary statistics from wearable sensors were analyzed by machine learning classification algorithms. These algorithms include k-nearest neighbors, logistic regression, naïve Bayes, random forest, and support vector machines (SVM). Each of these models were selected for their high interpretability. Each algorithm was tasked with classifying patients whose SAW trials MDS-UPDRS FOG subscore was non-zero as assessed by a trained movement disorder specialist. These algorithms' performance was evaluated using stratified five-fold cross-validation. Results: A total of 21 PD subjects were evaluated (average age 64.24 years, 16 males, mean disease duration of 14 years). Fourteen subjects had freezing of gait in the OFF MED/OFF DBS. All machine learning models achieved statistically similar predictive performance (p < 0.05) with high accuracy. Analysis of random forests' feature estimation revealed the top-ten spatiotemporal predictive features utilized in the model: foot strike angle, coronal range of motion [trunk and lumbar], stride length, gait speed, lateral step variability, and toe-off angle. Conclusion: These results indicate that machine learning effectively classifies advanced PD patients as freezers or nonfreezers based on SAW trials in their non-medicated/non-stimulated condition. The machine learning models, specifically random forests, not only rely on but utilize salient spatial and temporal gait features for FOG classification.

Altered connectivity between frontal cortex and supplementary motor area in various types of Parkinson's disease.

BACKGROUND: Tremor-dominant (TD) and postural instability/gait difficulty (PIGD) are common subtypes of Parkinson's disease, each with distinct clinical manifestations and prognoses. The neural mechanisms underlying these subtypes remain unclear. This study aimed to investigate the altered connectivity of the frontal cortex and supplementary motor area (SMA) in different types of Parkinson's disease. METHODS: Data of 173 participants, including 41 TD patients, 65 PIGD patients, and 67 healthy controls, were retrospectively analyzed. All subjects underwent resting-state functional magnetic resonance imaging (rs-fMRI) and clinical assessments. Differences in amplitude of low frequency fluctuation (ALFF), voxel-wise functional connectivity (FC), and functional network connectivity (FNC) among the three groups were compared, followed by partial correlation analysis. RESULTS: Compared to healthy controls, the left dorsolateral superior frontal gyrus (DLSFG) ALFF was significantly increased in both PIGD and TD patients. The FC between the left DLSFG and the left SMA, as well as between the left paracentral lobule and the right DLSFG, was significantly decreased. Similarly, the FNC between the visual network and the auditory network was reduced. Compared to TD patients, PIGD patients showed a significantly higher ALFF in the left DLSFG and a notably reduced FC between the left DLSFG and left SMA. Additionally, the FC of the left DLSFG-SMA was inversely correlated with the PIGD score exclusively in PIGD patients. The FNC of the visual-auditory network was inversely associated with the tremor score only in TD patients. CONCLUSION: Decreases in the left DLSFG-SMA connectivity may be a key feature of the PIGD subtype, while reduced VN-AUD connectivity may characterize the TD subtype.

Circular walking is useful for assessing the risk of falls in early progressive supranuclear palsy.

BACKGROUND: Progressive supranuclear palsy (PSP) is characterized by early onset postural instability and frequent falls. Circular walking necessitates dynamic postural control, which is impaired in patients with PSP. We aimed to explore gait parameters associated with the risk of falls in patients with PSP, focusing on circular walking. METHODS: Sixteen drug-naïve patients with PSP, 22 drug-naïve patients with Parkinson's disease (PD), and 23 healthy controls were enrolled. Stride lengths/velocities and their coefficients of variation (CV) during straight and circular walking (walking around a circle of 1-m diameter) were measured under single-task and cognitive dual-task conditions. Correlation analysis was performed between gait parameters and postural instability and gait difficulty (PIGD) motor subscores, representing the risk of falls. RESULTS: Patients with PSP had significantly higher CVs of stride lengths/velocities during circular walking than those during straight walking, and the extent of exacerbation of CVs in patients with PSP was larger than that in patients with PD under single-task conditions. Stride lengths/velocities and their CVs were significantly correlated with PIGD motor subscores in patients with PSP only during single-task circular walking. In addition, patients with PSP showed progressive decrements of stride lengths/velocities over steps only during single-task circular walking. CONCLUSIONS: Worse gait parameters during circular walking are associated with an increased risk of falls in patients with PSP. Circular walking is a challenging task to demand the compromised motor functions of patients with PSP, unmasking impaired postural control and manifesting sequence effect. Assessing circular walking is useful for evaluating the risk of falls in patients with early PSP.