Mecánica y energética durante la marcha en cinta caminadora en Adultos Uruguayos Saludables: efecto del IMC y la edad

La evaluación de la marcha en cinta caminadora puede resultar relevante para la toma de decisiones clínicas. No obstante, factores demográficos como la edad y el IMC pueden alterar la interpretación de los resultados. Nuestro objetivo fue obtener variables espacio- temporales, energéticas y costo de transporte durante la velocidad autoseleccionada en cinta caminadora para una muestra representativa de adultos uruguayos (n=28) y evaluar si diferentes rangos de edades e IMC pueden ser factores a tener en cuenta en pruebas clínicas donde se consideren dichas variables. Participaron 17 hombres y 11 mujeres (39,3 ± 14,8 años, 75,9 ± 12,5 kg, 1,74 ± 0,09 m, IMC 25,2 ± 4,06). Se realizó una reconstrucción 3D del movimiento en forma sincronizada con el consumo energético. Se obtuvieron valores de referencia y luego de agrupar los participantes según su IMC y rango de edad se compararon los datos mediante test de t (p≤0.05). Los resultados revelaron discrepancias significativas en las medidas espacio-temporales y energéticas de los adultos uruguayos al caminar en cinta con respecto a la literatura. La marcha difiere entre adultos jóvenes y de mediana edad en su velocidad autoseleccionada (p=0,03), longitud de zancada (p=0,01), trabajo mecánico externo (<0,001) y recuperación de energía mecánica (0,009), destacando la importancia de considerar la edad en evaluaciones clínicas. El IMC no influyó significativamente en estas variables. Estos hallazgos subrayan la necesidad de ajustar las interpretaciones de las pruebas clínicas de la marcha sobre cinta caminadora en adultos uruguayos de mediana edad (45 a 65 años).

Treadmill gait assessment can be relevant for clinical decision-making. However, demographic factors such as age and BMI may alter result interpretation. Our aim was to obtain spatiotemporal, energetic, and cost of transport variables during self-selected treadmill walking speed for a representative sample of Uruguayan adults (n=28) and to assess if different age ranges and BMI could be factors to consider in clinical tests involving these variables. Seventeen men and eleven women participated (39.3 ± 14.8 years, 75.9 ± 12.5 kg, 1.74 ± 0.09 m, BMI 25.2 ± 4.06). A synchronized 3D motion reconstruction was performed with energy consumption. Reference values were obtained and data were compared using t-tests (p≤0.05), after grouping participants by BMI and age range. Results revealed significant discrepancies in spatiotemporal and energetic measures of Uruguayan adults walking on the treadmill, compared to the literature. Gait differed between young and middle-aged adults in their self-selected speed (p=0.03), stride length (p=0.01), external mechanical work (p<0.001), and mechanical energy recovery (0.009), emphasizing the importance of considering age in clinical evaluations. BMI did not significantly influence these variables. These findings underscore the need to adjust interpretations of treadmill gait clinical tests in middle-aged Uruguayan adults (45 to 65 years).

A avaliação da marcha na esteira pode ser relevante para a tomada de decisões clínicas. No entanto, fatores demográficos como idade e IMC podem alterar a interpretação dos resultados. Nosso objetivo foi obter variáveis espaço-temporais, energéticas e custo de transporte durante a velocidade de caminhada autoselecionada na esteira para uma amostra representativa de adultos uruguaios (n = 28) e avaliar se diferentes faixas etárias e IMC podem ser fatores a serem considerados em testes clínicos que envolvam essas variáveis. Dezessete homens e onze mulheres participaram (39,3 ± 14,8 anos, 75,9 ± 12,5 kg, 1,74 ± 0,09 m, IMC 25,2 ± 4,06). Foi realizada uma reconstrução tridimensional do movimento sincronizada com o consumo de energia. Foram obtidos valores de referência e os dados foram comparados usando testes t (p≤0,05), após agrupar os participantes por IMC e faixa etária. Os resultados revelaram discrepâncias significativas nas medidas espaço-temporais e energéticas dos adultos uruguaios ao caminhar na esteira, em comparação com a literatura. A marcha diferiu entre adultos jovens e de meia-idade em sua velocidade autoselecionada (p=0,03), comprimento da passada (p=0,01), trabalho mecânico externo (<0,001) e recuperação de energia mecânica (0,009), destacando a importância de considerar a idade em avaliações clínicas. O IMC não influenciou significativamente essas variáveis. Esses achados destacam a necessidade de ajustar as interpretações dos testes clínicos de marcha na esteira em adultos uruguaios de meia- idade (45 a 65 anos).

[Lower limb joint contact forces and ground reaction forces analysis based on Azure Kinect motion capture].

Traditional gait analysis systems are typically complex to operate, lack portability, and involve high equipment costs. This study aims to establish a musculoskeletal dynamics calculation process driven by Azure Kinect. Building upon the full-body model of the Anybody musculoskeletal simulation software and incorporating a foot-ground contact model, the study utilized Azure Kinect-driven skeletal data from depth videos of 10 participants. The in-depth videos were prepossessed to extract keypoint of the participants, which were then adopted as inputs for the musculoskeletal model to compute lower limb joint angles, joint contact forces, and ground reaction forces. To validate the Azure Kinect computational model, the calculated results were compared with kinematic and kinetic data obtained using the traditional Vicon system. The forces in the lower limb joints and the ground reaction forces were normalized by dividing them by the body weight. The lower limb joint angle curves showed a strong correlation with Vicon results (mean ρ values: 0.78 ~ 0.92) but with root mean square errors as high as 5.66°. For lower limb joint force prediction, the model exhibited root mean square errors ranging from 0.44 to 0.68, while ground reaction force root mean square errors ranged from 0.01 to 0.09. The established musculoskeletal dynamics model based on Azure Kinect shows good prediction capabilities for lower limb joint forces and vertical ground reaction forces, but some errors remain in predicting lower limb joint angles.

Effect of a Rehabilitation Program Including Home-Based Vibration-Assisted Therapy on Gait Parameters in Children with Cerebral Palsy.

OBJECTIVES: The aim of the present study was to examine the effects of a rehabilitation program combined with a home-based vibration-assisted therapy on gait parameters in children with cerebral palsy (CP). METHODS: In a retrospective study, 180 children, 101 boys and 79 girls, (mean age 7.2 ± 3.3 years) with CP at Gross Motor Function Classification System (GMFCS) Level I and Level II were examined using gait analyses with the Leonardo Mechanograph® Gangway at three measurement points. The measurements were conducted before (M0) and after a six-month rehabilitation period (M6), as well as 12 months after the commencement of rehabilitation (M12). The difference between measurement points M6-M0 (treatment interval) and M12-M6 (follow-up interval) were compared, and significance was determined using the Wilcoxon test. RESULTS: Children with CP at GMFCS Level I and II demonstrated a significant improvement in gait efficiency (pathlength/distance M6-M0: -0.053 (SD 0.25) vs M12-M6: -0.008 (0.36), p=0.038). There were no significant difference in change of mean velocity and average step length between M6-M0 and M12-M6 (p=0.964 and p=0.611). CONCLUSIONS: The rehabilitation program seems to enhance gait efficiency in children with CP. German Clinical Trial Registry: DRKS0001131 at www.germanctr.de.

Effect of Upper Limb Repetitive Facilitative Exercise on Gait of Stroke Patients based on Artificial Intelligence and Computer Vision Evaluation.

OBJECTIVE: This study aims to assess how enhancing upper limb function on the affected side of stroke influences the gait of the lower limb. METHODS: Forty eligible stroke patients were randomly assigned to either a control group or a treatment group, with 20 patients in each group. Both groups underwent dynamic evaluation using artificial intelligence and computer vision before treatment. This evaluation focused on analyzing the range of motion of the shoulder and elbow during the gait cycle, as well as various gait parameters (such as step length, step speed, and percentage of stance phase) on the affected side. Following evaluation, the control group received routine rehabilitation treatment. RESULTS: The results indicated that there was no significant difference between the two groups before treatment. However, following treatment, there was a notable improvement in the motion of the shoulder and elbow joints on the affected side among patients in the treatment group (p<0.05), whereas the control group showed only slight improvement, which was not statistically significant (p>0.05). CONCLUSION: The improvement in upper limb function on the affected side also appears to positively influence gait recovery. However, it's important to note that the observation period was relatively short. Further studies are needed to confirm whether this effect is sustained over the long term.

Effect of acceptance and commitment therapy on fear of falling and physical activity in Parkinson's disease: a randomised controlled trial.

Introduction: This study aimed to evaluate the efficacy of acceptance and commitment therapy (ACT) in reducing the fear of falling (FOF) and promoting physical activity in individuals diagnosed with Parkinson's disease (PD). Methods and analysis: This is a prospective, multicentre, rater-blinded and randomised controlled trial. Patients with PD and a history of falls will be randomly assigned to either an 8-week ACT intervention group or a control group receiving standard care. The primary outcomes measured will include FOF assessment using the Falls Efficacy Scale-International and physical activity levels measured via wearable sensor devices. Secondary outcomes will encompass the assessment of motor function, balance and fall frequency using the Movement Disorder Society Unified Parkinson's Disease Rating Scale, Berg Balance Scale and Timed Up and Go test. Objective measures of balance and physical activity will be obtained through static posturography and wearable sensors over a 3-day period, both before and after the intervention. Data will be analysed using mixed-effects models to evaluate the impact of ACT on FOF and physical activity. Ethics and dissemination: We hypothesised that ACT would lead to a significant reduction in FOF and an increase in physical activity levels compared with standard care. Additionally, this study will also examine the relationship between reduced FOF and improvements in balance and motor function. Our results will provide valuable evidence to support the effectiveness of ACT in reducing FOF and promoting physical activity among patients with PD, and if validated, ACT could be recommended as a beneficial intervention to enhance the quality of life and reduce fall-related morbidity in patients with PD.

Robotic Assisted TKA achieves adjusted mechanical alignment targets more consistently compared to manual TKA without improving outcomes.

Introduction: Robotic total knee arthroplasty (rTKA), with its purported advantages of more accurate alignment, greater functional outcomes and patient satisfaction, is gaining popularity in patients undergoing TKA. The purpose of our study was to compare these parameters along with gait pattern and kneeling ability in a cohort of patients who underwent simultaneous TKA with manual instrumentation (mTKA) and rTKA in contralateral knees at a 1-year follow-up. Methods: This was a retrospective review of 135 consecutive patients who underwent simultaneous bilateral TKA using robotic assistance on one side and manual instrumentation on the contralateral side between January 2022 and June 2022. The target alignment in both cohorts was adjusted mechanical. Patients were followed up at 3, 6 and 12 months to assess and compare alignment, range of motion (ROM) and patient-reported outcome measures (PROM) data. Gait parameters and kneeling ability were assessed at 1-year follow-up. Results: While adjusted mechanical alignment was achieved in all rTKA patients, we recorded five outliers (≥3° with relation to 180° HKA axis) in the mTKA cohort (three varus and two valgus). There were no significant differences between both cohorts with regards to ROM, PROM scores, gait analysis parameters and kneeling ability at 1-year follow-up. Conclusion: rTKA helps in achieving the adjusted mechanical alignment more consistently than mTKA. This, however, does not contribute to better functional outcomes and patient satisfaction at 1-year follow-up. Level of Evidence: Level III.

Posture, balance and gait in axial spondyloarthritis: a case-control study.

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily involves the axial skeleton but may also present with peripheral joint involvement and extra-articular involvement. The present study aims to quantitatively analyze posture, balance, and gait parameters in patients with axSpA and and assess associated factors. This cross-sectional case-control study included 51 axSpA patients (30 males, 21 females; mean age 40.94 ± 10.48 years) and 51 age- and sex-matched healthy controls. In patients with axSpA, the Ankylosing Spondylitis Disease Activity Score CRP, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Functional Index (BASFI), the Bath Ankylosing Spondylitis Metrology Index (BASMI), the Maastrich Ankylosing Spondylitis Enthesitis Score (MASES), and the Ankylosing Spondylitis Quality of Life (ASQoL) scale were used. For postural analysis, DIERS formetric (Diers GmbH, Schlangenbad, Germany) videoraster- stereography device was utilized. HUR SmartBalance BTG4 (HUR-labs Oy, Kokkola, Finland) balance platform was used for postural balance and limit of stability (LOS) measurement. Participants were evaluated using Berg Balance Scale (BBS), Functional Reach Test (FRT) and Timed Up and Go Test (TUG). The Zebris FDM type 3 (Zebris Medical GmbH, Germany) walking platform was used to measure the spatiotemporal parameters of the participants. Comparison of postural parameters showed that sagittal imbalance and cervical depth distance were increased in the axSpA group than in the healthy participants (p < 0.004). Comparison of functional balance parameters showed that BBS and FRT scores were significantly lower (p < 0.001) in the axSpA group than in the control group, while TUG scores were significantly higher (p < 0.001). The LOS values, which evaluate dynamic balance were significantly lower, indicating impairment, in the axSpA group. In the measurement of postural sway, which indicates static balance, all 23 subparameters were found to be similar. When analyzing the spatiotemporal gait parameters, in the axSpA group compared with those in the control group; Foot angles (p= 0.028) and stride width (p = 0.004) were increased, whereas step lengths (p = 0.004) and stride lengths (P = 0.004) were decreased. In the axSpA group the gait speed was decreased (p = 0.004). When axSpA was analyzed separately as radiographic and nonradiographic axSpA, similar findings were observed in posture, balance, and gait parameters. No significant difference was observed. We found that the clinical assessments most closely associated with posture, balance, and gait analyses were BBS, FRT, TUG, and BASFI.

Methods to quantify gait rehabilitation following lower limb fractures.

Lower limb fragility fractures require long-term rehabilitation and are also very expensive to treat. Clinically, early weight bearing and walking stability were reported as key measures of fracture restoration. This study introduces methods to numerically quantify these performance indices for a range of ankle and knee joint fractures. As a follow-up of initial treatment, experimental data was collected using force plates from 367 subjects divided into seven groups: ankle fracture (AF), lower leg ankle fracture (AL), calcaneus foot fracture (CF), knee tibia fracture (KF), knee patella fracture (KP), kneecap rupture (KR), and normal limb (NL). For each joint, data was analysed to evaluate intralimb and interlimb weight-bearing and walking stability for all fracture conditions. These thresholds were statistically compared with normal subjects. Some advantages of evaluating fracture restoration indices over the others include:•to quantify fracture restoration (weight-bearing, walking stability, and gait symmetry) using minimum setup and signal requirements.•to provide comprehensive tools to assess and overcome fracture-associated complications through a detailed preview of fractured limb functionality during subphases of a gait cycle.•in clinical research, such assessments are important as a reference to evaluate existing or new rehabilitative interventions.

Delayed Onset Bilateral Vocal Cord Palsy in Miller Fisher Syndrome: The Rehabilitation Outcome.

Miller Fisher syndrome (MFS) typically presents with acute development of ataxia, ophthalmoplegia, and areflexia. Bilateral vocal cord palsy (BVCP) is a rare manifestation of MFS. We present a case of a 66-year-old male diagnosed with MFS complicated by an unusually delayed onset of BVCP while undergoing inpatient rehabilitation. We also describe the inpatient rehabilitation course, including the use of a patient-guided suspension system (PGSS) as a therapeutic adjunct to aid gait training, resulting in significant functional improvement in ambulation and activities of daily living. Given the rarity of BVCP in MFS, this case highlights the importance of healthcare professionals being aware of this phenomenon so that prompt treatment can be initiated to reduce significant morbidity. Innovative treatment approaches such as the use of a PGSS may also prove beneficial in the rehabilitation of patients with MFS with significant ataxia.

Functional impairments in NBIA patients: Preliminary results.

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group (genetically and phenotypically) of genetically determined disorders. Up to date there is no cure for this disease, so the applied treatments focus on symptoms control and palliative care. The main problems are delayed motor development, gait deterioration, postural instability, cognitive dysfunctions, abnormal muscle tone and many others. As gait and balance deficits are predominant features of NBIA patients this study aimed at the use of the objective, instrumented functional tests as well as functional assessment scales to assess their functional impairments. Twenty three NBIA patients recruited for the study underwent objective, instrumented gait analysis, balance assessment, pedobarography and functional evaluation with Gross Motor Function Measure (GMFM-88). The results showed high variability and heterogeneity of NBIA functional status (GMFM from 27.5 to 100.0), but also showed some differences in gait pattern between their types (p < 0.05 at the pelvis, hip and knee). We think that these results could help design objective assessment protocols in future clinical studies.

Efficacy of subthalamic deep brain stimulation programming strategies for gait disorders in Parkinson's disease: a systematic review and meta-analysis.

Patients with advanced Parkinson's disease often suffer from severe gait and balance problems, impacting quality of live and persisting despite optimization of standard therapies. The aim of this review was to systematically review the efficacy of STN-DBS programming techniques in alleviating gait disturbances in patients with advanced PD. Searches were conducted in PubMed, Embase, and Lilacs databases, covering studies published until May 2024. The review identified 36 articles that explored five distinct STN-DBS techniques aimed at addressing gait and postural instability in Parkinson's patients: low-frequency stimulation, ventral STN stimulation for simultaneous substantia nigra activation, interleaving, asymmetric stimulation and a short pulse width study. Among these, 21 articles were included in the meta-analysis, which revealed significant heterogeneity among studies. Notably, low-frequency STN-DBS demonstrated positive outcomes in total UPDRS-III score and FOG-Q, especially when combined with dopaminergic therapy. The most favorable results were found for low-frequency STN stimulation. The descriptive analysis suggests that unconventional stimulation approaches may be viable for gait problems in patients who do not respond to standard therapies.

Smart insole-based analysis of gait biomechanics for insoles in patients with flatfoot.

BACKGROUND: Assessing the effect of insoles on gait biomechanics and foot comfort remains challenging. Our novel in-insole-type wearable sensor device (smart insole) enables accurate quantitative evaluation of gait parameters without affecting the subject's foot comfort. RESEARCH QUESTION: What are the effects of insoles on gait biomechanics and foot comfort in patients with flatfoot, as evaluated using a novel smart insole? METHODS: Thirty-three subjects with 61 flatfeet were recruited. Three different types of prefabricated insoles were tested: a control insole as an experimental control, a flat insole with only cushion pads for the shock absorbing function, and an arch support insole with both cushioning pads and arch support functions. Gait parameters and visual analog scale (VAS) scores for foot comfort were measured during 30 m of straight walking with each insole incorporating the wearable sensor device. The differences in gait parameters and foot comfort between the flat and arch support insoles relative to the control insole were analyzed. Additionally, the correlations between gait parameters and foot comfort were evaluated. RESULTS: Maximum plantarflexion angle significantly decreased (p = 0.03) and the toe-out angle significantly increased (p < 0.01) with arch support insoles compared to flat insoles. Significantly better foot comfort was demonstrated when walking with arch support insoles than with flat insoles (p < 0.01). The only gait parameter correlated with foot comfort was foot lift height while walking with an arch support insole (r = -0.45, p < 0.01). SIGNIFICANCE: A novel smart insole revealed that foot lift height was a key gait parameter for determining foot comfort while walking with an arch support insole. Our findings provide important evidence for selecting a comfortable flatfoot insole based on gait data measured using a smart insole.

The impact of ankle-foot orthotics on selective motor control during gait in children and adolescents with cerebral palsy.

BACKGROUND: Children with cerebral palsy (CP) often exhibit altered selective motor control during gait (SMCg). Ankle-foot-orthoses (AFOs) are used in this population to improve gait, by reducing the degrees of freedom at the ankle joint. However, the specific impact of AFOs on SMCg and whether this effect is more related to gait deviations or motor development remains unclear. RESEARCH QUESTION: Do AFOs impact SMCg, and is the change related to joint kinematics or age? METHODS: Gait analysis data from 53 children and adolescents with spastic CP, walking both barefoot and with AFOs, were included. Electromyography data from six lower-limb muscles, and lower limb joint kinematics were analyzed for both walking conditions. SMCg was quantified by the total variance in electromyography activity accounted for by one synergy (tVAF1), where an increase in tVAF1 indicates a decrease in SMCg. Kinematic gait deviation was assessed using the Gait-Profile-Score (GPS) and sagittal plane ankle Gait-Variable-Score (ankle-GVS). All analyses were performed for the more clinically involved leg only. RESULTS: Walking with AFOs resulted in a mean increase in tVAF1 of 0.02±0.07 (p=0.015) and a median increase in ankle-GVS of 3.4º (p>0.001). No significant changes were observed in GPS, and no correlation was found between the changes in tVAF1 and ankle-GVS. A significant positive moderate correlation was found between the change in tVAF1 and age, even with ankle-GVS as a covariate (r=0.45; p>0.001). SIGNIFICANCE: Walking with an AFO resulted in a small decrease in SMCg, with large inter-participant variability. Younger participants showed a greater decrease in SMCg, which may indicate greater neuromuscular plasticity in early developmental stages.

Tibial acceleration alone is not a valid surrogate measure of tibial load in response to stride length manipulation.

PURPOSE: This study aimed to evaluate the relationship between peak tibial acceleration and peak ankle joint contact forces in response to stride length manipulation during level-ground running. METHODS: Twenty-seven physically active participants ran 10 trials at preferred speed in each of 5 stride length conditions: preferred, ±5%, and ±10% of preferred stride length. Motion capture, force platform, and tibial acceleration data were directly measured, and ankle joint contact forces were estimated using an inverse-dynamics-based static optimization routine. RESULTS: In general, peak axial tibial accelerations (p < 0.001) as well as axial (p < 0.001) and resultant (p < 0.001) ankle joint contact forces increased with stride length. When averaged within the 10 strides of each stride condition, moderate positive correlations were observed between peak axial acceleration and joint contact force (r = 0.49) as well as peak resultant acceleration and joint contact force (r = 0.51). However, 37% of participants illustrated either no relationship or negative correlations. Only weak correlations across participants existed between peak axial acceleration and joint contact force (r = 0.12) as well as peak resultant acceleration and ankle joint contact force (r = 0.18) when examined on a step-by-step basis. CONCLUSION: These results suggest that tibial acceleration should not be used as a surrogate for ankle joint contact force on a step-by-step basis in response to stride length manipulations during level-ground running. A 10-step averaged tibial acceleration metric may be useful for some runners, but an initial laboratory assessment would be required to identify these individuals.

Unraveling the mechanisms of high-level gait control in functional gait disorders.

Functional gait disorders (FGDs) are a disabling subset of Functional Neurological Disorders in which presenting symptoms arise from altered high-level motor control. The dual-task paradigm can be used to investigate mechanisms of high-level gait control. The study aimed to determine the objective measures of gait that best discriminate between individuals with FGDs and healthy controls and the relationship with disease severity and duration. High-level spatiotemporal gait outcomes were analyzed in 87 patients with FGDs (79.3% women, average age 41.9±14.7 years) and 48 healthy controls (60.4% women, average age 41.9±15.7 years) on single and motor, cognitive, and visual-fixation dual tasks. The area under the curve (AUC) from the receiver operator characteristic plot and the dual-task effect (DTE) were calculated for each measure. Dual-task interference on the top single-task gait characteristics was determined by two-way repeated measures ANOVA. Stride time variability and its standard deviation (SD) failed to discriminate between the two groups in single and dual-task conditions (AUC<0.80 for all). Significant group x task interactions were observed for swing time SD and stride time on the cognitive dual tasks (p<0.035 for all). Longer disease duration was associated with poor gait performance and unsteadiness in motor and cognitive DTE (p<0.003) but improvement in stride length and swing time on the visual dual tasks (p<0.041). Our preliminary findings shed light on measures of gait automaticity as a diagnostic and prognostic gait biomarker and underline the importance of early diagnosis and management in individuals with FGDs.

Perturbation walking effects on prefrontal cortical activation and walking performance in older women with and without osteoarthritis: a FNIRS study.

Introduction: Perturbation walking (PW) has been shown to improve gait, however its effect on the cortical control of gait might provide insights on neural mechanisms underlying falls in adults with osteoarthritis. The objective of this study is to investigate the effect of PW on prefrontal cortical (PFC) activation in older women with (OA) and without osteoarthritis (HOA). We hypothesized that there would be an increase in PFC activation during PW relative to comfortable walking (CW) and higher increase in PFC activation during PW in HOA compared to OA. Methods: Twenty community-dwelling older women (66.7 ± 5.41 years old) walked on an instrumented treadmill that provided perturbations at pseudo-random intervals between 5-25 s using a counterbalanced design. Functional Near Infrared Spectroscopy was used to quantify PFC oxygenated hemoglobin (HbO2) and deoxyhemoglobin (Hb) levels, while standing prior to the task as a baseline. A linear mixed effects model was conducted to investigate the effects of cohort (HOA vs OA), task (PW vs CW), and their interaction on HbO2 (µM) and Hb (µM) levels. Results: HbO2 and Hb levels differed significantly between CW and PW tasks for both cohorts (P < 0.001) and demonstrated significant task by cohort interaction (P < 0.05). In addition, we found changes in walking performance (stride time, stride length, stride width and stance time) during and after PW. Spearman correlation demonstrated a strong association between increased stance time, increased body mass index and decreased PFC activation during PW. No other significant results were found. Discussion: This study found increase in PFC activation during PW and gait adaptation after a short bout of PW in HOA and OA. This increase in PFC activation was higher in HOA compared to OA, particularly during PW tasks, and was consistent with theory of limitations in mobility affecting neural activation in older adults. Further work remains to examine how pain, obesity, and mobility impacts cortical control in older adults with and without osteoarthritis.

Effects of robot exoskeletal-assisted gait training on gait ability in a pediatric patient with peripheral polyneuropathy: a case report.

[Purpose] This study aims to investigate the effects of robotic exoskeleton-assisted gait training on a pediatric patient with peripheral polyneuropathy. [Participant and Methods] A 10-year-old boy with lower extremity weakness attributed to peripheral polyneuropathy underwent a two-week program comprising 10 rehabilitation sessions of powered robotic exoskeleton-assisted gait training (REGT). He was evaluated before and after treatment using the 10-meter walk test, 6-minute walk test, Berg Balance Scale, the Timed Up and Go Test, the Functional Reach Test, the Modified Functional Reach Test, hip and knee flexion/extension angles, and cardiopulmonary exercise testing. [Results] The patient demonstrated improved gait speed, balance, joint mobility, cadence, the maximum oxygen consumption and metabolic equivalents after the REGT. [Conclusion] Robotic exoskeleton devices could provide additional benefits to pediatric patients with peripheral polyneuropathy, pending larger studies to confirm the significance of treatment.

Relationships of B12 and Homocysteine with Outcomes in the SURE-PD, SURE-PD3, and STEADY-PDIII Trials.

Background: DATATOP was a study of early Parkinson's disease (PD) conducted in the 1980 s, before mandatory folic acid fortification in the United States. Our analysis of its baseline serum samples revealed a geometric mean vitamin B12 of 369 pg/mL and homocysteine (tHcy) of 9.5µmol/l. We also found that low B12 predicted greater worsening of ambulatory capacity (AC) and elevated tHcy (>15µmol/L) predicted greater declines in cognitive function. Objective: We sought to measure B12 and tHcy in contemporary trial participants with early PD who had not started dopaminergic treatment and to determine whether these analytes were associated with clinical progression. Methods: We measured B12 and tHcy from baseline and end-of-study blood samples from three recent clinical trials. Results: Baseline geometric mean B12 levels for these studies ranged from 484- 618 pg/ml and for tHcy ranged from 7.4- 10µmol/L. Use of B12-containing supplements ranged from 41- 61%, and those taking supplements had higher B12 and lower tHcy. Those who began levodopa, but were not taking B12-supplements, had greater end-of-study tHcy. There was no association of baseline tHcy > 15µmol/L with annualized change in Montreal Cognitive Assessment and no association of baseline B12 tertiles with change in AC. Conclusions: In these longitudinal trials, B12 levels were higher than for DATATOP, due in large part to increased B12-supplement intake, while tHcy levels were similar. Initiation of levodopa was associated with increases of tHcy in those not taking a B12-containing supplement. These smaller studies did not replicate prior findings of low B12 and elevated tHcy with features of progression, possibly due to higher baseline B12.

Soft ankle exoskeleton to counteract dropfoot and excessive inversion.

Introduction: Wearable exoskeletons are emerging technologies for providing movement assistance and rehabilitation for people with motor disorders. In this study, we focus on the specific gait pathology dropfoot, which is common after a stroke. Dropfoot makes it difficult to achieve foot clearance during swing and heel contact at early stance and often necessitates compensatory movements. Methods: We developed a soft ankle exoskeleton consisting of actuation and transmission systems to assist two degrees of freedom simultaneously: dorsiflexion and eversion, then performed several proof-of-concept experiments on non-disabled persons. The actuation system consists of two motors worn on a waist belt. The transmission system provides assistive force to the medial and lateral sides of the forefoot via Bowden cables. The coupling design enables variable assistance of dorsiflexion and inversion at the same time, and a force-free controller is proposed to compensate for device resistance. We first evaluated the performance of the exoskeleton in three seated movement tests: assisting dorsiflexion and eversion, controlling plantarflexion, and compensating for device resistance, then during walking tests. In all proof-of-concept experiments, dropfoot tendency was simulated by fastening a weight to the shoe over the lateral forefoot. Results: In the first two seated tests, errors between the target and the achieved ankle joint angles in two planes were low; errors of <1.5° were achieved in assisting dorsiflexion and/or controlling plantarflexion and of <1.4° in assisting ankle eversion. The force-free controller in test three significantly compensated for the device resistance during ankle joint plantarflexion. In the gait tests, the exoskeleton was able to normalize ankle joint and foot segment kinematics, specifically foot inclination angle and ankle inversion angle at initial contact and ankle angle and clearance height during swing. Discussion: Our findings support the feasibility of the new ankle exoskeleton design in assisting two degrees of freedom at the ankle simultaneously and show its potential to assist people with dropfoot and excessive inversion.

Exploring the contribution of joint angles and sEMG signals on joint torque prediction accuracy using LSTM-based deep learning techniques.

Machine learning (ML) has been used to predict lower extremity joint torques from joint angles and surface electromyography (sEMG) signals. This study trained three bidirectional Long Short-Term Memory (LSTM) models, which utilize joint angle, sEMG, and combined modalities as inputs, using a publicly accessible dataset to estimate joint torques during normal walking and assessed the performance of models, that used specific inputs independently plus the accuracy of the joint-specific torque prediction. The performance of each model was evaluated using normalized root mean square error (nRMSE) and Pearson correlation coefficient (PCC). Each model's median scores for the PCC and nRMSE values were highly convergent and the bulk of the mean nRMSE values of all joints were less than 10%. The ankle joint torque was the most successfully predicted output, having a mean nRMSE of less than 9% for all models. The knee joint torque prediction has reached the highest accuracy with a mean nRMSE of 11% and the hip joint torque prediction of 10%. The PCC values of each model were significantly high and remarkably comparable for the ankle (∼ 0.98), knee (∼ 0.92), and hip (∼ 0.95) joints. The model obtained significantly close accuracy with single and combined input modalities, indicating that one of either input may be sufficient for predicting the torque of a particular joint, obviating the need for the other in certain contexts.