A larger augmented-reality field of view improves interaction with nearby holographic objects.

Augmented-reality (AR) applications have shown potential for assisting and modulating gait in health-related fields, like AR cueing of foot-placement locations in people with Parkinson's disease. However, the size of the AR field of view (AR-FOV), which is smaller than one's own FOV, might affect interaction with nearby floor-based holographic objects. The study's primary objective was to evaluate the effect of AR-FOV size on the required head orientations for viewing and interacting with real-world and holographic floor-based objects during standstill and walking conditions. Secondary, we evaluated the effect of AR-FOV size on gait speed when interacting with real-world and holographic objects. Sixteen healthy middle-aged adults participated in two experiments wearing HoloLens 1 and 2 AR headsets that differ in AR-FOV size. To confirm participants' perceived differences in AR-FOV size, we examined the head orientations required for viewing nearby and far objects from a standstill position (Experiment 1). In Experiment 2, we examined the effect of AR-FOV size on head orientations and gait speeds for negotiating 2D and 3D objects during walking. Less downward head orientation was required for looking at nearby holographic objects with HoloLens 2 than with HoloLens 1, as expected given differences in perceived AR-FOV size (Experiment 1). In Experiment 2, a greater downward head orientation was observed for interacting with holographic objects compared to real-world objects, but again less so for HoloLens 2 than HoloLens 1 along the line of progression. Participants walked slightly but significantly slower when interacting with holographic objects compared to real-world objects, without any differences between the HoloLenses. To conclude, the increased size of the AR-FOV did not affect gait speed, but resulted in more real-world-like head orientations for seeing and picking up task-relevant information when interacting with floor-based holographic objects, improving the potential efficacy of AR cueing applications.

Effects of shuttle balance exercises on gait speed, postural control, and quality of life in older males: A randomized controlled trial.

BACKGROUND AND PURPOSE: Enhancing physical function and quality of life in older adults at higher risk of falls is challenging because of the lack of established interventions. This study examines the impact of a 6-week balance training program using the shuttle balance device on gait speed, postural control, and quality of life in older men. METHODS: This single-blinded randomized controlled trial was conducted in a research laboratory. Thirty-two participants aged ≥60 years were randomly assigned to either an experimental group (EG; n = 16) or a control group (CG; n = 14). The EG participated in a 6-week shuttle balance exercise program, while the CG maintained regular physical activity routines. The main outcome measures included gait speed (assessed via the timed up and go test), postural control (assessed via center of pressure data on a force plate), and quality of life (evaluated using the SF-36 questionnaire). RESULTS: Post-intervention, the EG showed significant improvements compared with the CG (p < 0.05). The 95% confidence intervals for the differences between groups were as follows: closed eyes (CE) mean velocity (-39.07, -0.13), CE sway area (-48.86, -0.18), SF-36 total score (9.01, 16.81), SF-36 physical functioning (7.00, 24.81), SF-36 physical role functioning (1.80, 27.57), SF-36 pain (15.01, 36.82), SF-36 general health state (7.48, 26.08), SF-36 vitality (5.60, 28.35), and SF-36 mental health (0.21, 21.12). DISCUSSION: A 6-week shuttle balance training program significantly improves postural control and quality of life in older males. These findings suggest the potential effectiveness of shuttle balance exercises in enhancing physical function and well-being in this population. Further research is needed to validate these findings and explore the long-term effects with larger sample sizes.

A bidirectional pedestrian macroscopic speed model construction based on pedestrian microscopic simulation experiments.

Studies of macroscopic speed modeling of bidirectional pedestrian cross-flows have relied heavily on scenario experiments, but the data itself may be deficient because large-scale scenario experiments are not easy to organize and subjects may not be walking under normal conditions. In order to explore the possibility of using microscopic pedestrian flow simulations for macroscopic speed modeling of pedestrian flows, a series of two-way pedestrian cross-flow simulation experiments were designed. Bidirectional pedestrian flows are defined as Peds1 and Peds2. The crossing angle and pedestrian flow rate are used as variables, and a bidirectional pedestrian flows simulation is designed as an orthogonal experiment. The crossing angles range from 15 to 165 degrees, and bidirectional pedestrian flow rate range from 1 ped/s to 8 ped/s. A series of simulations are built and performed on the GIS agent-based modeling architecture (GAMA) platform. By analyzing the flow data of bidirectional flows in the crossing area, it is found that when the Peds1 density falls below a threshold, Peds1 speed is determined by pedestrians themselves and mainly remains in a free flow state; otherwise, the Peds1 speed decreases with density. The clear effects such as Peds2 density on the Peds1 speed cannot be determined. A piecewise function combined with a linear function and an exponential function is constructed as the Peds1 speed model considering the influence of the crossing angle. The calibration results show that the piecewise function should be better than the non-piecewise function. Compared to the results of established studies, the results in this paper have some differences. Therefore, the simulation method cannot completely replace the scene experiments. However, this approach can provide suggestions for subsequent refinement of the experimental program, as well as a feasible direction for the construction of a speed relationship for bidirectional pedestrian flows.

Mobile Spatiotemporal Gait Segmentation Using an Ear-Worn Motion Sensor and Deep Learning.

Mobile health technologies enable continuous, quantitative assessment of mobility and gait in real-world environments, facilitating early diagnoses of gait disorders, disease progression monitoring, and prediction of adverse events like falls. Traditionally, mobile gait assessment predominantly relied on body-fixed sensors positioned at the feet or lower trunk. Here, we investigate the potential of an algorithm utilizing an ear-worn motion sensor for spatiotemporal segmentation of gait patterns. We collected 3D acceleration profiles from the ear-worn sensor during varied walking speeds in 53 healthy adults. Temporal convolutional networks were trained to detect stepping sequences and predict spatial relations between steps. The resulting algorithm, mEar, accurately detects initial and final ground contacts (F1 score of 99% and 91%, respectively). It enables the determination of temporal and spatial gait cycle characteristics (among others, stride time and stride length) with good to excellent validity at a precision sufficient to monitor clinically relevant changes in walking speed, stride-to-stride variability, and side asymmetry. This study highlights the ear as a viable site for monitoring gait and proposes its potential integration with in-ear vital-sign monitoring. Such integration offers a practical approach to comprehensive health monitoring and telemedical applications, by integrating multiple sensors in a single anatomical location.

Walking pace is a protective factor for rheumatoid arthritis: a mendelian randomization study.

Walking pace is a simple and functional form of exercise and a strong predictor of health, but little is known about its causal association with rheumatoid arthritis. This study aimed to investigate the causal effect of WP on the developing RA using Mendelian randomization analysis. The genetic variation associated with WP was selected as an instrumental variable from the latest genome-wide association studies. Summary-level data for the outcomes were obtained from the corresponding GWAS. The inverse-variance weighted method was used as the primary MR analysis. The results were further tested using a multivariable MR approach based on Bayesian model averaging. Confounders (BMI, SMK, HBP, TD) with close associations with RA were included in the analysis. An observational study with individual data from UK Biobank was performed to reinforce our findings. The MR results indicated the significant inverse associations of WP with the risk of RA (odds ratio (OR), 0.31; 95% confidence interval (CI), 0.15, 0.62; p = 1.05 × 10 -3). After adjusting for the risk factors, the associations for WP and RA did not change substantially. Observational study results demonstrated the same effect of WP on reducing the risk of RA. The Mendelian randomization analysis and observational study provide evidence suggesting that walking pace is a protective factor for rheumatoid arthritis. Given its simple measurement, walking pace may be a pragmatic target for interventions.

Exploring unsupervised feature extraction of IMU-based gait data in stroke rehabilitation using a variational autoencoder.

BACKGROUND: Variational AutoEncoders (VAE) might be utilized to extract relevant information from an IMU-based gait measurement by reducing the sensor data to a low-dimensional representation. The present study explored whether VAEs can reduce IMU-based gait data of people after stroke into a few latent features with minimal reconstruction error. Additionally, we evaluated the psychometric properties of the latent features in comparison to gait speed, by assessing 1) their reliability; 2) the difference in scores between people after stroke and healthy controls; and 3) their responsiveness during rehabilitation. METHODS: We collected test-retest and longitudinal two-minute walk-test data using an IMU from people after stroke in clinical rehabilitation, as well as from a healthy control group. IMU data were segmented into 5-second epochs, which were reduced to 12 latent-feature scores using a VAE. The between-day test-retest reliability of the latent features was assessed using ICC-scores. The differences between the healthy and the stroke group were examined using an independent t-test. Lastly, the responsiveness was determined as the number of individuals who significantly changed during rehabilitation. RESULTS: In total, 15,381 epochs from 107 people after stroke and 37 healthy controls were collected. The VAE achieved data reconstruction with minimal errors. Five latent features demonstrated good-to-excellent test-retest reliability. Seven latent features were significantly different between groups. We observed changes during rehabilitation for 21 and 20 individuals in latent-feature scores and gait speed, respectively. However, the direction of the change scores of the latent features was ambiguous. Only eleven individuals exhibited changes in both latent-feature scores and gait speed. CONCLUSION: VAEs can be used to effectively reduce IMU-based gait assessment to a concise set of latent features. Some latent features had a high test-retest reliability and differed significantly between healthy controls and people after stroke. Further research is needed to determine their clinical applicability.

Relationship between different muscle mass indices and physical performance measures in Turkish older adults.

BACKGROUND: Sarcopenia, characterized by the loss of skeletal muscle, is assessed using appendicular skeletal muscle mass indices (ASMI). Various international groups propose different ASMI thresholds for assessing sarcopenia. However, the optimal ASMI that correlates best with physical performance measures in older Turkish adults remains unexplored. This study aims to determine which ASMI is most closely associated with physical performance measures, particularly low handgrip strength (dynapenia), in Turkish older adults. METHODS: The study included 326 individuals aged 60 and above. Comprehensive geriatric assessments were conducted on all participants, along with anthropometric evaluations and body composition analyses. ASMI was calculated by adjusting height squared, weight, and body mass index (BMI). Physical performance was assessed through handgrip strength, gait speed, and the chair stand test. RESULTS: The mean age of the participants was 74 ± 5.77 years, with 59.8% being women and 37.5% having dynapenia. Height-squared adjusted ASMI was not significantly associated with gait speed or the chair stand test. Weight-adjusted ASMI correlated with handgrip strength and gait speed but not with the chair stand test. Both height and weight-adjusted ASMI did not differ significantly between participants with and without dynapenia (p > 0.05). BMI-adjusted ASMI significantly correlated with all physical performance parameters (p < 0.05). Furthermore, in multivariate regression analysis, BMI-adjusted ASMI (OR = 0.028, 95% CI = 0.01-0.31, p = 0.006) was independently associated with dynapenia. CONCLUSION: The study indicates that ASMI adjusted for BMI shows stronger correlations with all physical performance parameters and is independently associated with dynapenia. Utilizing ASMI adjusted for BMI may improve sarcopenia diagnosis in Turkish older adults.

Sex-dependent interplay of phosphate and inflammation on muscle strength irrespective of muscle mass in middle-aged and older adults.

BACKGROUND: Elevated circulatory phosphate levels are linked to age-related muscle dysfunction, yet the mechanisms remain unclear. This study investigated the hypothesis that inflammation plays a role in connecting elevated phosphate levels to muscular dysfunction in middle-aged and older individuals and explored potential sex-based differences in these associations. METHODS: The study, based on the I-Lan Longitudinal Aging Study Cohort, analyzed individuals' serum phosphate and hsCRP levels. Sex-specific analyses explored links between circulatory phosphate, inflammation, and muscle profiles (mass, handgrip strength, and walking speed). The study also examined potential mediation or synergistic effects of inflammation in the circulatory phosphate-muscle relationship. RESULTS: The study included 2006 participants (mean age: 65.5 ± 6.5 years; 49.8 % men). Women exhibited higher circulatory phosphate levels than men. Linear analyses revealed that higher phosphate levels were significantly associated with weaker handgrip strength but not with reduced muscle mass in both men and women. In women, circulatory phosphate was not associated with inflammation (hsCRP levels), while in men, higher phosphate levels were significantly associated with higher hsCRP levels. In men, a synergistic effect was observed, where the combination of high hsCRP and elevated phosphate levels had a more pronounced impact on reducing handgrip strength than either factor alone. CONCLUSIONS: This study highlights a sex-specific association of inflammation in the mechanisms of hyperphosphatemia-related muscle weakness. The findings emphasize the importance of managing both hyperphosphatemia and chronic inflammation to mitigate their collective impact on muscle function, particularly in older men. Addressing these factors is crucial for promoting muscle health in later life.

Association of gait speed and handgrip strength with falls in older adults: the role of cognition.

Background/aim: Fall risk assessment is crucial for older adults because falls are associated with morbidity and mortality. This study investigated the relationship of gait speed (GS) and handgrip strength (HGS) with falls and assessed whether cognition mediates this causality. Materials and methods: The study was conducted in a tertiary referral geriatric outpatient clinic. The physical performance of participants was evaluated by GS and HGS. All falls in the previous year were noted and factors associated with falls were analyzed using multivariate regression analysis. Results: A total of 1018 older adults with a mean age of 78.8 ± 7.2 years, 64.2% of whom were female, were stratified into two groups: those who were cognitively impaired (n = 331) and those who were cognitively healthy (n = 660). In the study population, 22.8% (n = 226) had a history of falls in the previous year. The rates of low GS and HGS were 29.1% and 80.6%, respectively. After adjusting for confounding factors, low GS (OR = 2.01, 95% CI: 1.10-3.77, p = 0.019), low HGS (OR = 3.57, 95% CI: 1.10-11.35, p = 0.038), and low GS plus low HGS (OR = 4.52, 95% CI: 1.14-15.78, p = 0.024) in the cognitively impaired group and low GS (OR = 2.13, 95% CI: 1.39-3.52, p = 0.003) in the cognitively healthy group were independently associated with falls. Conclusion: GS is an efficient and practical assessment tool for identifying older adults at risk of falls regardless of their cognitive status.

Does spastic myopathy determine active movement and ambulation speed in chronic spastic paresis?-A cross-sectional study on plantar flexors.

BACKGROUND: Functional correlates of spastic myopathy, the muscle disorder of spastic paresis, are unknown. OBJECTIVE: To explore reciprocal relationships between clinical and structural parameters of plantar flexors with i) ambulation speed, ii) dorsiflexion and plantarflexion torques in chronic hemiparesis. METHODS: Cross-sectional trial in chronic stroke-induced hemiparesis (>6 months). Plantar flexors were quantified through i) the Five Step Assessment: maximal extensibility (XV1), active range of dorsiflexion (XA); ii) ultrasonography: fascicle length (Lf) and thickness (Th) of medial gastrocnemius (GAS) and soleus (SOL), knee extended in an isokinetic ergometer, ankle at 80% XV1-GAS. Maximal isometric torques in plantar flexion (PF) and dorsiflexion (DF) and maximal barefoot 10-meter ambulation speed were collected. Relationships between structural, biomechanical, clinical and functional parameters were explored using non-parametric testing (Spearman). RESULTS: Twenty-one subjects (age 58.0±8.4, mean±SD, time since lesion 7.8±5.7 years) were recruited, with the following characteristics: ambulation speed, 0.77±0.37m/sec; XV1-SOL 92.7±10.3°; XV1-GAS 91.3±9.6°; XA-SOL 86.9±10.0°; XA-GAS 7676±14.2°; LfGAS, 58.2±18.3mm; ThGAS, 17.1±3.6 mm; LfSOL, 36.0±9.6 mm; ThSOL, 13.8±3.3mm; PF peak-torque 46.5±34.1Nm, DF peak-torque, 20.1±19.1Nm. XA-SOL and XA-GAS strongly correlated with XV1-SOL and XV1-GAS respectively (ρ = 0.74, p = 4E-04; resp ρ = 0.60, p = 0.0052). Ambulation speed moderately correlated with LfGAS (ρ = 0.51, p = 0.054), ThGAS (ρ = 0.58, p = 0.02) and LfSOL (ρ = 0.63, p = 0.009). DF and PF peak-torques both correlated with LfGAS (ρ = 0.53, p = 0.04) a; resp. ρ = 0.71, p = 0.0015). CONCLUSION: In chronic hemiparesis, active dorsiflexion is mostly determined by plantar flexor extensibility. Plantar flexor fascicle shortening is associated with reduced ambulation speed and ankle torques. Attempts to restore plantar flexor extensibility might be important objectives for gait rehabilitation in chronic hemiparesis.

Brain-body-task co-adaptation can improve autonomous learning and speed of bipedal walking.

Inspired by animals that co-adapt their brain and body to interact with the environment, we present a tendon-driven and over-actuated (i.e.njoint,n+1 actuators) bipedal robot that (i) exploits its backdrivable mechanical properties to manage body-environment interactions without explicit control,and(ii) uses a simple 3-layer neural network to learn to walk after only 2 min of 'natural' motor babbling (i.e. an exploration strategy that is compatible with leg and task dynamics; akin to childsplay). This brain-body collaboration first learns to produce feet cyclical movements 'in air' and, without further tuning, can produce locomotion when the biped is lowered to be in slight contact with the ground. In contrast, training with 2 min of 'naïve' motor babbling (i.e. an exploration strategy that ignores leg task dynamics), does not produce consistent cyclical movements 'in air', and produces erratic movements and no locomotion when in slight contact with the ground. When further lowering the biped and making the desired leg trajectories reach 1 cm below ground (causing the desired-vs-obtained trajectories error to be unavoidable), cyclical movements based on either natural or naïve babbling presented almost equally persistent trends, and locomotion emerged with naïve babbling. Therefore, we show how continual learning of walking in unforeseen circumstances can be driven by continual physical adaptation rooted in the backdrivable properties of the plant and enhanced by exploration strategies that exploit plant dynamics. Our studies also demonstrate that the bio-inspired co-design and co-adaptations of limbs and control strategies can produce locomotion without explicit control of trajectory errors.

Insights into muscle metabolic energetics: Modelling muscle-tendon mechanics and metabolic rates during walking across speeds.

The metabolic energy rate of individual muscles is impossible to measure without invasive procedures. Prior studies have produced models to predict metabolic rates based on experimental observations of isolated muscle contraction from various species. Such models can provide reliable predictions of metabolic rates in humans if muscle properties and control are accurately modeled. This study aimed to examine how muscle-tendon model individualization and metabolic energy models influenced estimation of muscle-tendon states and time-series metabolic rates, to evaluate the agreement with empirical data, and to provide predictions of the metabolic rate of muscle groups and gait phases across walking speeds. Three-dimensional musculoskeletal simulations with prescribed kinematics and dynamics were performed. An optimal control formulation was used to compute muscle-tendon states with four levels of individualization, ranging from a scaled generic model and muscle controls based on minimal activations, inclusion of calibrated muscle passive forces, personalization of Achilles and quadriceps tendon stiffnesses, to finally informing muscle controls with electromyography. We computed metabolic rates based on existing models. Simulations with calibrated passive forces and personalized tendon stiffness most accurately estimate muscle excitations and fiber lengths. Interestingly, the inclusion of electromyography did not improve our estimates. The whole-body average metabolic cost was better estimated with a subset of metabolic energy models. We estimated metabolic rate peaks near early stance, pre-swing, and initial swing at all walking speeds. Plantarflexors accounted for the highest cost among muscle groups at the preferred speed and were similar to the cost of hip adductors and abductors combined. Also, the swing phase accounted for slightly more than one-quarter of the total cost in a gait cycle, and its relative cost decreased with walking speed. Our prediction might inform the design of assistive devices and rehabilitation treatment. The code and experimental data are available online.

Causality between sarcopenia and diabetic neuropathy.

Background: Past studies have demonstrated that diabetic neuropathy is related to sarcopenia, but the further causal relation is still unclear. We sought to investigate the causal relationship by combining data from cross-sectional and Mendelian randomization (MR) studies. Methods: The genome-wide association studies data were collected from the UK Biobank and the European Working Group on Sarcopenia to conduct a bi-directional two-sample MR study to explore the causality between diabetic neuropathy and relevant clinical traits of sarcopenia, including appendicular lean mass (ALM), walking speed and low hand grip strength. The inverse-variance weighted and various sensitivity analyses were used to obtain MR estimates. We also enrolled a total of 196 Type 2 diabetes patients from April 2021 to April 2024 and divided them into the Distal peripheral neuropathy (DPN) group (n=51) and non-DPN group (n=145) via vibration perception threshold (VPT) and neuropathy deficit score. Logistic regression and ROC curve analysis were used to investigate the relationship between DPN and relevant sarcopenia clinical features. Results: According to a forward MR analysis, decreased walking speed (OR: 0.04, 95% confidence interval (CI): 0.01-0.16; P<0.001) and increased ALM (1.25 [1.05-1.50], P=0.012) had a causal effect on developing diabetic neuropathy. According to reverse MR results, developing diabetic neuropathy had a causal effect on decreased walking speed (0.99 [0.99-1.00], P=0.007) and low grip strength (1.05 [1.02-1.08], P<0.001). The cross-sectional study showed that 5-time stand time (P=0.002) and 6-meter walking speed (P=0.009) had an inverse association with DPN. Additionally, we discovered that ASMI (P=0.030) and 5-time stand time (P=0.013) were separate risk factors for DPN.ConclusionThe MR study suggested that diabetic neuropathy may have a causality with relevant clinical traits of sarcopenia, and our cross-sectional study further proved that sarcopenia indexes are predictors of diabetic neuropathy.

Causal roles of circulating cytokines in sarcopenia-related traits: a Mendelian randomization study.

Background: Epidemiological and experimental evidence suggests that chronic inflammation plays an important role in the onset and progression of sarcopenia. However, there is inconsistent data on the inflammatory cytokines involved in the pathogenesis of sarcopenia. Therefore, we performed a two-sample Mendelian randomization (MR) analysis to explore the causal relationship between circulating cytokines and sarcopenia-related traits. Methods: The MR analysis utilized genetic data from genome-wide association study that included genetic variations in 41 circulating cytokines and genetic variant data for appendicular lean mass (ALM), hand grip strength, and usual walking pace. Causal associations were primarily explored using the inverse variance-weighted (IVW) method, supplemented by MR-Egger, simple mode, weighted median, and weighted mode analyses. Additionally, sensitivity analyses were also performed to ensure the reliability and stability of the results. Results: Three cytokines [hepatocyte growth factor (HGF), interferon gamma-induced protein 10 (IP-10), and macrophage colony-stimulating factor (M-CSF)] were positively associated with ALM (ß: 0.0221, 95% confidence interval (CI): 0.0071, 0.0372, P= 0.0039 for HGF; ß: 0.0096, 95%CI: 4e-04, 0.0189, P= 0.0419 for IP-10; and ß: 0.0100, 95%CI: 0.0035, 0.0165, P= 0.0025 for M-CSF). Conversely, higher levels of interleukin-7 (IL-7), monocyte chemotactic protein 3 (MCP-3), and regulated on activation, normal T cell expressed and secreted (RANTES) were associated with decreased hand grip strength (ß: -0.0071, 95%CI: -0.0127, -0.0014, P= 0.0140 for IL-7; ß: -0.0064, 95%CI: -0.0123, -6e-04, P= 0.0313 for MCP-3; and ß: -0.0082, 95%CI: -0.0164, -1e-04, P= 0.0480 for RANTES). Similarly, interleukin 1 receptor antagonist (IL-1RA) was negatively correlated with usual walking pace (ß: -0.0104, 95%CI: -0.0195, -0.0013, P= 0.0254). Sensitivity analysis confirmed the robustness of these findings. Conclusions: Our study provides additional insights into the pivotal role of specific inflammatory cytokines in the pathogenesis of sarcopenia. Further research is required to determine whether these cytokines can be used as targets for the prevention and treatment of sarcopenia.

Clinical effect of anti-resistance exercise combined with nutritional intervention in the treatment of elderly patients with sarcopenia.

This study aims to evaluate the efficacy of a combined intervention involving resistance exercise and nutritional support in improving grip strength, walking speed, and skeletal muscle density among elderly individuals suffering from sarcopenia. Data from a cohort of 500 elderly sarcopenic patients were segregated into observation and control cohorts based on distinct treatment modalities. Baseline evaluations included weight, grip strength, walking speed, and skeletal muscle density. Changes in these parameters and oxidative stress markers were monitored and compared at 1-, 3-, and 6-month intervals. Baseline grip strength for the observation and control groups stood at (20.25 ±â€…2.34) and (21.06 ±â€…2.97) kg, respectively. Walking speed was measured at (0.99 ±â€…0.12) and (0.98 ±â€…0.20) m/s, respectively. Skeletal muscle density registered (42.98 ±â€…4.17) and (42.77 ±â€…5.02) Hu for the observation and control groups, respectively, while muscle mass index was recorded as (6.19 ±â€…1.46) and (6.20 ±â€…1.68) kg/m2, respectively. Limb skeletal muscle mass for both cohorts was (16.83 ±â€…3.57) and (16.77 ±â€…3.89) kg. No significant disparities were discerned in baseline characteristics between the groups. Following 1, 3, and 6 months, the observation group exhibited marked enhancements in grip strength and walking speed (P < .05), with substantially superior grip strength compared to the control cohort (P < .05). Notably, skeletal muscle density, muscle mass index, and limb skeletal muscle mass exhibited significant augmentation in the observation group (P < .05), while no significant alterations were observed in the control cohort. Oxidative stress-related parameters displayed no notable differences between groups pretreatment (P > .05). Post-treatment, levels of Hcy, IFN-γ, and MDA markedly decreased in both groups, with considerably lower levels evident in the observation cohort (P < .05). Moreover, SOD levels exhibited significant post-treatment increments in both groups, with markedly higher levels observed in the observation group (P < .05). An integrated approach of resistance exercise and nutritional support significantly enhances grip strength, walking speed, and skeletal muscle density in elderly patients with sarcopenia, contributing to better prognoses and improved quality of life.

Longitudinal association between dentition status and gait speed among older Brazilian adults: SABE cohort study.

BACKGROUND: Oral health has been associated with general health conditions, but few longitudinal studies evaluated the effect of dentition status on gait speed. OBJECTIVE: This study aimed to investigate the longitudinal association between different time-varying measures of dentition status (i.e., number of teeth, the presence of periodontal pockets and the functional impact of oral health) and gait speed (outcome) in older Brazilian adults. MATERIALS AND METHODS: This was a prospective study using data from the Health, Well-being and Aging cohort study (SABE) from 2006, 2010 and 2015. The gait speed was the dependent variable and the independent variables of interest were dentition status evaluated using the number of teeth, use of dental prostheses, presence of periodontal pocket, clinical attachment loss and self-perceived poor functional oral health. Dentition status measures were obtained through clinical oral examinations, performed by trained dentists using standardized criteria proposed by the World Health Organization. Self-perceived poor functional oral health was evaluated using the functional domain of the Geriatric Oral Health Assessment Index. The longitudinal effect of dentition status on gait speed was evaluated using mixed-effects linear models. The effect of the number of teeth/periodontal pocket/attachment loss on gait speed change over time was evaluated by including an interaction term between these variables. The effect of periodontal pocket was tested only among dentate individuals. RESULTS: Data for the complete sample included 3,306 observations from 1,964 individuals. The analyses for dentate individuals included 1,883 observations from 1,149 individuals. There was a positive association between the number of teeth and mean gait speed. Individuals using dental prostheses also had higher means of gait speed than those without dental prostheses. Gait speed was lower among individuals with periodontal pockets and with attachment loss. No interaction was found between any of the indicators of dentition status and time. CONCLUSION: Gait speed was associated with dentition status and this association was constant over time.

GaitKeeper: An AI-Enabled Mobile Technology to Standardize and Measure Gait Speed.

Gait speed is increasingly recognized as an important health indicator. However, gait analysis in clinical settings often encounters inconsistencies due to methodological variability and resource constraints. To address these challenges, GaitKeeper uses artificial intelligence (AI) and augmented reality (AR) to standardize gait speed assessments. In laboratory conditions, GaitKeeper demonstrates close alignment with the Vicon system and, in clinical environments, it strongly correlates with the Gaitrite system. The integration of a cloud-based processing platform and robust data security positions GaitKeeper as an accurate, cost-effective, and user-friendly tool for gait assessment in diverse clinical settings.

Springs vs. motors: Ideal assistance in the lower limbs during walking at different speeds.

Recent years have witnessed breakthroughs in assistive exoskeletons; both passive and active devices have reduced metabolic costs near preferred walking speed by assisting muscle actions. Metabolic reductions at multiple speeds should thus also be attainable. Musculoskeletal simulation can potentially predict the interaction between assistive moments, muscle-tendon mechanics, and walking energetics. In this study, we simulated devices' optimal assistive moments based on minimal muscle activations during walking with prescribed kinematics and dynamics. We used a generic musculoskeletal model with tuned muscle-tendon parameters and computed metabolic rates from muscle actions. We then simulated walking across multiple speeds and with two ideal actuation modes-motor-based and spring-based-to assist ankle plantarflexion, knee extension, hip flexion, and hip abduction and compared computed metabolic rates. We found that both actuation modes considerably reduced physiological joint moments but did not always reduce metabolic rates. Compared to unassisted conditions, motor-based ankle plantarflexion and hip flexion assistance reduced metabolic rates, and this effect was more pronounced as walking speed increased. Spring-based hip flexion and abduction assistance increased metabolic rates at some walking speeds despite a moderate decrease in some muscle activations. Both modes of knee extension assistance reduced metabolic rates to a small extent, even though the actuation contributed with practically the entire net knee extension moment during stance. Motor-based hip abduction assistance reduced metabolic rates more than spring-based assistance, though this reduction was relatively small. Our study also suggests that an assistive strategy based on minimal muscle activations might result in a suboptimal reduction of metabolic rates. Future work should experimentally validate the effects of assistive moments and refine modeling assumptions accordingly. Our computational workflow is freely available online.

Modeling the Heterogeneity of Post-Stroke Gait Control in Free-Living Environments Using a Personalized Causal Network.

Post-stroke gait control is a complex, often fail to account for the heterogeneity and continuity of gait in existing gait models. Precisely evaluating gait speed adjustability and gait instability in free-living environments is important to understand how individuals with post-stroke gait dysfunction approach diverse environments and contexts. This study aimed to explore individual causal interactions in the free-living gait control of persons with stroke. To this end, fifty persons with stroke wore an accelerometer on the fifth lumbar vertebra (L5) for 24 h in a free-living environment. Individually directed acyclic graphs (DAGs) were generated based on the spatiotemporal gait parameters at contemporaneous and temporal points calculated from the acceleration data. Spectral clustering and Bayesian model comparison were used to characterize the DAGs. Finally, the DAG patterns were interpreted via Bayesian logistic analysis. Spectral clustering identified three optimal clusters from the DAGs. Cluster 1 included persons with moderate stroke who showed high gait asymmetry and gait instability and primarily adjusted gait speed based on cadence. Cluster 2 included individuals with mild stroke who primarily adjusted their gait speed based on step length. Cluster 3 comprised individuals with mild stroke who primarily adjusted their gait speed based on both step length and cadence. These three clusters could be accurately classified based on four variables: Ashman's D for step velocity, Fugl-Meyer Assessment, step time asymmetry, and step length. The diverse DAG patterns of gait control identified suggest the heterogeneity of gait patterns and the functional diversity of persons with stroke. Understanding the theoretical interactions between gait functions will provide a foundation for highly tailored rehabilitation.

Patterns of change in propulsion force and late braking force in patients with stroke walking at comfortable and fast speeds.

Increased propulsion force (PF) in the paretic limb is associated with improved walking speed in patients with stroke. However, late braking force (LBF), an additional braking force occurring between PF onset and toe-off, is present in a subset of stroke patients. Few studies have investigated the changes in LBF and walking speed in these patients. This study aimed to elucidate the patterns of change in PF and LBF during fast gait in hemiplegics and identify potential compensatory strategies based on the LBF patterns. Data from 100 patients with stroke walking at both comfortable (mean, 0.79 ± 024 m/s) and fast speeds (mean, 1.06 ± 0.35 m/s) were analyzed retrospectively stroke using a 3D motion analyzer. PF was higher during fast-speed walking than that during comfortable-speed walking in all patients, while LBF showed both decreasing and increasing trends during fast-speed walking. In the LBF increasing pattern, a reduction in in-phase coordination of the shank and foot during the pre-swing phase was observed, along with an increase in pelvic hike during fast-speed walking compared to those in the decreasing LBF pattern. Our findings demonstrate that alterations in LBF patterns are associated with gait deviations in patients with stroke at fast speeds.