Step Time Research Articles

Asymmetric shoe height induces reactive changes in gait kinematics but not kinetics in healthy young adults

BackgroundFootwear interventions are a potential avenue to correct walking asymmetry in neurologic populations, such as stroke. However, the motor learning mechanisms that underlie the changes in walking imposed by asymmetric footwear are unclear. Research questionThe objectives of this study were to examine symmetry changes during and after an asymmetric shoe height intervention in (1) vertical impulse and (2) spatiotemporal gait parameters and (3) joint kinematics, in healthy young adults MethodsEleven healthy young adults (3 males, 8 females; 21.2 ± 3.1 years old) participated in this study. Participants walked on an instrumented treadmill at 1.3 m/s for four conditions: (1) a 5-minute familiarization with equal shoe height, (2) a 5-minute baseline with equal shoe height, (3) a 10-minute intervention, where participants walked with asymmetric shoe height with a 10 mm shoe insert in one shoe, and (4) a 10-minute post-intervention, where participants walked with equal shoe height. Asymmetry in kinetics and kinematics were used to identify changes during intervention and aftereffects, a hallmark of feedforward adaptation ResultsParticipants did not alter vertical impulse asymmetry (p = 0.667) nor stance time asymmetry (p = 0.228). During the intervention, step time asymmetry (p = 0.003) and double support asymmetry (p < 0.001) were greater compared to baseline. Leg joint asymmetry during stance (Ankle plantarflexion: p < 0.001; Knee flexion: p < 0.001; Hip extension: p = 0.011) was greater during the intervention compared to baseline. However, changes in spatiotemporal gait variables and joint mechanics did not demonstrate aftereffects. SignificanceOur results show that healthy human adults change gait kinematics, but not weight-bearing symmetry with asymmetrical footwear. This suggests that healthy humans prioritize maintaining vertical impulse by changing their kinematics. Further, the changes in gait kinematics are short-lived, suggesting feedback-based control, and a lack of feedforward motor adaptations

Impacts of gait biomechanics of patients with thoracolumbar kyphosis secondary to Scheuermann's disease.

Introduction: Thoracolumbar kyphosis (TLK) is a common feature in patients with spinal deformities. However, due to limited studies, the impacts of TLK on gait have not been reported. The objective of the study was to quantify and evaluate the impacts of gait biomechanics of patients with TLK secondary to Scheuermann's disease. Methods: Twenty cases of Scheuermann's disease patients with TLK and twenty cases of asymptomatic participants were recruited into this study. And the gait motion analysis was conducted. Results: The stride length was shorter in the TLK group compared to control group (1.24 ± 0.11m vs. 1.36 ± 0.21m, p = 0.04). Compared to control group, the stride time and step time were more prolonged in the TLK group (1.18 ± 0.11s vs. 1.11 ± 0.08s, p = 0.03; 0.59 ± 0.06s vs. 0.56 ± 0.04s, p = 0.04). The gait speed of the TLK group was significantly slower than it of control group (1.05 ± 0.12m/s vs. 1.17 ± 0.14m/s, p = 0.01); In the sagittal plane, the range of motion (ROM) of the hip in the TLK group was significantly smaller than that of the control group (37.71 ± 4.35° vs. 40.05 ± 3.71°, p = 0.00). In the transverse plane, the adduction/abduction ROMs of the knee and ankle, as well as the internal and external rotation of the knee, were smaller in TLK group than ROMs in the control group (4.66 ± 2.21° vs. 5.61 ± 1.82°, p = 0.00; 11.48 ± 3.97° vs. 13.16 ± 5.6°, p = 0.02; 9.00 ± 5.14° vs. 12.95 ± 5.78°, p = 0.00). Discussion: The main finding of this study was that measurements of gait patterns and joint movement of the TLK group were significantly lower than those of the control group. And these impacts have the potential to exacerbate degenerative progress of joints in the lower extremities. These abnormal features of gait can also serve as a guideline for physicians to focus on TLK in these patients.

The relationship between sleep quality and gait in people with multiple sclerosis: A pilot study.

Gait deficits are common among people with multiple sclerosis (PwMS). Therefore, investigating factors that may influence walking in PwMS is important. Previous studies in older adults and other neurological populations demonstrated the relationship between sleep quality and gait performance. Despite the fact that the prevalence of poor sleep quality is very high among PwMS, little is known about the effect of sleep quality on gait among PwMS. This study aimed to explore the relationship between sleep quality and gait performance in PwMS. Forty-one PwMS participated in the study between February 2019 and December 2019. Participants were asked to walk at a self-selected speed over 10 m with an inertial measurement unit (IMU) attached over the back. Walking speed, step length (left and right), and step time were calculated. Sleep was estimated objectively using a wrist-worn triaxle-accelerometer; the derived parameters were sleep efficiency (SE) and the number of awakening after sleep onset (NASO). SE significantly correlated with step length (). Furthermore, the NASO significantly correlated with gait speed (), and step-time (). These correlations remained significant even after adjusting for age and disease duration. We observed that when corrected for disease duration and age there were relationships between NASO and SE to gait parameters; these observations warrant further investigations.

A high efficiency Lie derivative algorithm for the nonautonomous nonlinear systems

Numerical procedure plays a key role in tackling the solutions of nonlinear dynamical systems. With the advent of the age of big data and high-power computing, developing efficient and fast numerical algorithms is an urgent task. This paper extends the Lie derivative discretization algorithm to the nonautonomous nonlinear systems and investigates the numerical solutions of the systems. The periodic solutions of three different classical nonlinear systems are calculated, and the results are compared to those values calculated from the Runge–Kutta fourth-order algorithm, which demonstrated that the Lie derivative algorithm has the advantages of large time step and short computation time.

Numerical Aspects of a Continuum Sintering Model Formulated in the Standard Dissipative Framework

Robust and computationally efficient numeric algorithms are required to simulate the sintering process of complex ceramic components by means of the finite element method. This work focuses on a thermodynamically consistent sintering model capturing the effects of both, viscosity and elasticity, within the standard dissipative framework. In particular, the temporal integration of the model by means of several implicit first and second order accurate one step time integration methods is discussed. It is shown in terms of numerical experiments on the material point level that the first order schemes exhibit poor performance when compared to second order schemes. Further numerical experiments indicate that the results translate directly to finite element simulations.

Understanding the Role of Children's Footwear on Children's Feet and Gait Development: A Systematic Scoping Review.

Children's footwear plays an important role in the healthy growth of foot and gait development during the growing stage. This review aims to synthesize findings of previous investigations and to explore the biomechanical influences of different types of children's footwear on foot health and gait development, thus guiding the healthy and safe growth of children's feet and gait. Online databases were searched for potential eligible articles, including Web of Science, Google Scholar, and PubMed. In total, nineteen articles were identified after searching based on the inclusion requirements. The following five aspects of biomechanical parameters were identified in the literature, including spatiotemporal, kinematics, kinetics, electromyography (EMG), and plantar pressure distribution. Children's footwear can affect their foot health and gait performance. In addition, children's shoes with different flexibility and sole hardness have different effects on children's feet and gait development. Compared to barefoot, the stride length, step length, stride time, and step time were increased, but cadence was decreased with wearing shoes. Furthermore, the support base and toe-off time increased. Double support time and stance time increased, but single support time decreased. The hip, knee, and ankle joints showed increased range of motion in children with the rear-foot strike with larger ground reaction force as well. Future studies may need to evaluate the influence of footwear types on gait performance of children in different age groups. Findings in this study may provide recommendations for suitable footwear types for different ages, achieving the aim of growth and development in a healthy and safe manner.

Level of Agreement between the MotionMetrix System and an Optoelectronic Motion Capture System for Walking and Running Gait Measurements

Markerless motion capture systems (MCS) have been developed as an alternative solution to overcome the limitations of 3D MCS as they provide a more practical and efficient setup process given, among other factors, the lack of sensors attached to the body. However, this might affect the accuracy of the measures recorded. Thus, this study is aimed at evaluating the level of agreement between a markerless MSC (i.e., MotionMetrix) and an optoelectronic MCS (i.e., Qualisys). For such purpose, 24 healthy young adults were assessed for walking (at 5 km/h) and running (at 10 and 15 km/h) in a single session. The parameters obtained from MotionMetrix and Qualisys were tested in terms of level of agreement. When walking at 5 km/h, the MotionMetrix system significantly underestimated the stance and swing phases, as well as the load and pre-swing phases (p &lt; 0.05) reporting also relatively low systematic bias (i.e., ≤ −0.03 s) and standard error of the estimate (SEE) (i.e., ≤0.02 s). The level of agreement between measurements was perfect (r &gt; 0.9) for step length left and cadence and very large (r &gt; 0.7) for step time left, gait cycle, and stride length. Regarding running at 10 km/h, bias and SEE analysis revealed significant differences for most of the variables except for stride time, rate and length, swing knee flexion for both legs, and thigh flexion left. The level of agreement between measurements was very large (r &gt; 0.7) for stride time and rate, stride length, and vertical displacement. At 15 km/h, bias and SEE revealed significant differences for vertical displacement, landing knee flexion for both legs, stance knee flexion left, thigh flexion, and extension for both legs. The level of agreement between measurements in running at 15 km/h was almost perfect (r &gt; 0.9) when comparing Qualisys and MotionMetrix parameters for stride time and rate, and stride length. The agreement between the two motion capture systems varied for different variables and speeds of locomotion, with some variables demonstrating high agreement while others showed poor agreement. Nonetheless, the findings presented here suggest that the MotionMetrix system is a promising option for sports practitioners and clinicians interested in measuring gait variables, particularly in the contexts examined in the study.

Spectral parameters of gait differentiate diabetic patients from healthy individuals

BackgroundDiabetes mellitus (DM) is a clinical condition that affects gait performance and control in millions of individuals worldwide. Contrary to basic spatiotemporal parameters, gait-based spectral analysis may provide useful insights into gait neuromotor control. Hence, this study was set to investigate the spectral content of gait at the preferred speed in patients with DM. MethodsTotal 1117 individuals [658 DM and 649 healthy adults (HA)] performed a 10 m walk while wearing an inertial measurement unit over the fourth lumbar vertebra. Mann-Whitney-U test was used for between-group gait parameters comparisons. ResultsDM group had a slower step time (1.2%, p < 0.05) and gait speed (2.4%, p < 0.05) than HA. Additionally, DM individuals showed reduced dominant frequency (DM:0.24 Hz vs HA:0.25 Hz on average, p < 0.05). Increased antero-posterior and vertical dominant frequency width (DM:1.73 Hz vs HA:1.76 Hz on average, p < 0.05) and medio-lateral relative power spectral density at the dominant frequency (DM:6.19% vs HA:5.96%, p < 0.05). ConclusionsIt was demonstrated for the first time that the gait spectral content, not only corroborates spatiotemporal characteristics, but also provides further insight into their neuromotor control deficits in diabetic patients. Ultimately, this type of analysis in the diabetic population can help guide the therapeutic interventions to prevent diabetic foot.

Preparation of Al52Sn28Bi20 particles with morphology-controlled core–shell structure by the pulsated orifice ejection method

The core–shell structure is commonly found in immiscible alloy droplets, but their formation route is hindered by the uncontrollable thermal history of droplets prepared through traditional methods. To address this issue, the pulsated orifice ejection method was used to prepare core–shell structure particles with a consistent thermal history. Our study identified a formation route for core–shell structures, wherein the second phase of the outer layer of the particle migrates and coalesces to form the core. It was found that the step time of the pulsated orifice ejection method strongly influenced the final morphology. These findings have significant implications for understanding the formation mechanism of core–shell structures.

The gait parameters in patients with Parkinson’s Disease under STN-DBS therapy and associated clinical features

ABSTRACT Objective We aimed to investigate the gait parameters in patients with subthalamic nucleus deep brain stimulation (STN-DBS) therapy using quantitative gait analyses and reveal the associated clinical features. Methods Parkinson’s disease (PD) subjects with STN-DBS who applied to our movement disorders outpatient clinics between December/2021 and March/2022 were enrolled. In addition to the evaluation of the demographic data and the clinical features; clinical scales measuring the freezing of gait (FOG), falls and quality of life were performed. A gait analyzer program was used to perform gait analysis. Results Thirty patients with a mean age of 59.4 ± 8.3 (F/M = 7/23) were enrolled. The comparative analyses between the tremor-dominant and akinetic-rigid (AR) subtype patients showed that the step time asymmetry measures were higher in the AR group. The comparative analyses according to the symptom onset side showed that the step length was smaller in those with left-side symptom onset. The correlation analyses showed that there were correlations between the quality-of-life indexes and FOG questionnaire and falls efficacy scale (FES) scores. Finally, the correlation analyses between clinical scales and gait parameters revealed that there were significant correlations between the FES scores and the step length asymmetry (SLA). Conclusion We found a strong relationship between falls and quality of life indexes of our patients under STN-DBS therapy. In this patient group, particular evaluation of fallings and the follow-up of SLA in gait analysis may constitute important points during the evaluation of patients in routine clinical practice.

TRACK & ACT: a pragmatic randomised controlled trial exploring the comparative effectiveness of pedometers and activity trackers for changing physical activity and sedentary behaviour in inactive individuals

BackgroundPedometers have been shown to be effective for increasing physical activity, however the potential additional effects of activity trackers, and their added capacity to simultaneously modify sedentary behaviour, has not been thoroughly explored. This study aimed to explore the comparative effectiveness of two activity trackers and a pedometer for improving daily step count and moderate-vigorous physical activity (MVPA), and reducing sedentary behaviour in inactive adults.Methods48 inactive participants were allocated to one of three groups based on their workplace. Each group randomly received either a Fitbit ONE, Jawbone UP or Digi-Walker SW200 pedometer (PED) for 8-weeks and an orientation session to their respective device. Participants were informed about the study aims and were provided with their respective devices and where applicable, the associated Apps. Participants intentionally received no other active intervention components to simulate as closely as possible the experience of purchasing a device ‘off the shelf’. Step count, MVPA and time in sedentary behaviour were measured using accelerometry (Actigraph GT3X+) at baseline and four-, eight- and 16-weeks. Analyses were conducted using linear mixed-effect regression models to compare changes from baseline. Post-hoc tests of model estimates compared each activity tracker group to the pedometer group. Model estimates are reported for baseline-16 week follow-up.ResultsAt baseline, average (standard deviation) step count, MVPA and time spent sedentary was 6557 (2111) steps/day, 23 (13) minutes/day and 10.3 (1.0) hours/day in the PED group, 7156 (1496) steps/day, 26 (12) minutes/day and 9.3 (1.2) hours/day in the ONE group and 6853 (1281) steps/day, 29 (10) minutes/day and 10.1 (1.0) hours/day in the UP group. At 16-weeks, based on estimates from the linear mixed-effect regression model, the ONE and UP groups increased step count by 129 steps/day (95% CI − 1497, 1754) and 504 steps/day more (95% CI − 1120, 2130), respectively, than the PED group. For MVPA, the ONE and UP groups increased by 2.3 min/day (95% CI − 10.9, 15.4) and 2.7 min/day more (95% CI − 10.5, 15.8), respectively, than the PED group. For sedentary behaviour, the ONE group had 34 min/day more in time spent sedentary than the PED group (95% CI − 35, 104), while the UP group had 53 min/day more in time spent sedentary than the PED group (95% CI − 18, 123).ConclusionsAll three groups demonstrated an increase in steps and MVPA, and a decrease in time spent in sedentary behaviour, however there was substantial individual variation in these outcomes indicating considerable uncertainty about the relative effectiveness of activity trackers and pedometers in improving PA and sedentary behaviour. Randomised controlled trials with adequate sample sizes are indicated.Trial registrationACTRN12623000027617 (retrospectively registered 11/1/2023).

Autonomous Control of Music to Retrain Walking After Stroke

Background Post-stroke care guidelines highlight continued rehabilitation as essential; however, many stroke survivors cannot participate in outpatient rehabilitation. Technological advances in wearable sensing, treatment algorithms, and care delivery interfaces have created new opportunities for high-efficacy rehabilitation interventions to be delivered autonomously in any setting (ie, clinic, community, or home). Methods We developed an autonomous rehabilitation system that combines the closed-loop control of music with real-time gait analysis to fully automate patient-tailored walking rehabilitation. Specifically, the mechanism-of-action of auditory-motor entrainment is applied to induce targeted changes in the post-stroke gait pattern by way of targeted changes in music. Using speed-controlled biomechanical and physiological assessments, we evaluate in 10 individuals with chronic post-stroke hemiparesis the effects of a fully-automated gait training session on gait asymmetry and the energetic cost of walking. Results Post-treatment reductions in step time (Δ: −12 ± 26%, P = .027), stance time (Δ: −22 ± 10%, P = .004), and swing time (Δ: −15 ± 10%, P = .006) asymmetries were observed together with a 9 ± 5% reduction (P = .027) in the energetic cost of walking. Changes in the energetic cost of walking were highly dependent on the degree of baseline energetic impairment (r =− .90, P < .001). Among the 7 individuals with a baseline energetic cost of walking larger than the normative value of healthy older adults, a 13 ± 4% reduction was observed after training. Conclusions The closed-loop control of music can fully automate walking rehabilitation that markedly improves walking after stroke. Autonomous rehabilitation delivery systems that can safely provide high-efficacy rehabilitation in any setting have the potential to alleviate access-related care gaps and improve long-term outcomes after stroke.

The Effect of Gaitlike Plantar Stimulation During Walking

The plantar surfaces of the feet are a vital source of information for balance and locomotion control. They use the location of the center of pressure (CoP) to aid in the control of standing and walking balance. However, during gait this CoP traverses along the foot from the heel to the toe. Stimulating the plantar surfaces in a manner that can positively affect the perception of this CoP movement could increase balance control during walking tasks in the presence of plantar sensory deficits. In individuals with such deficits, applying vibro-tactile stimulation to increase this CoP movement perception may lead to enhanced relearning of balance during gait. The purpose of this study was to investigate the effects of different patterns of vibro-tactile stimulation on balance control during different walking tasks in healthy subjects. We hypothesized that vibro-tactile stimulation in an abnormal pattern will result in gait and balance deficits, when compared to stimulation that follows a natural walking pattern. Additionally, that walking on an inclined surface would exaggerate the effects of these stimulation patterns. In this on-going study we tested three stimulation patterns at three different inclines (0, 5, and 10-degrees) of treadmill walking. These patterns included no stimulation (NS), a gait-like stimulation (GS), and a reverse gait-like stimulation (RGS). Minimal differences from these patterns were observed in spatiotemporal measures (&lt;2% from NS in step time and length; &lt;5% from NS in step width) at each incline. However, RGS compared to NS led to ~ 30% decrease in foot placement distribution during level and 5-degrees of incline. The GS pattern however remained similar to regular walking at both 0 and 5-degrees of incline (both ~5%). These foot placement effects did not lead to decreases in stability when measured with margin of stability changes. Stimulating the plantar surfaces in different patterns, therefore, alters how the body uses plantar afferents during gait through the control of foot placements. Stimulation in the regular sequence (GS) is important for maintaining natural foot placement during level walking and small inclines while disrupted tactile patterns (RGS) can restrict such natural locomotion. Currently ongoing brain imaging studies are expected to provide in-depth understanding of how such regular walking patterns influence sensorimotor organization and control. This project was supported by grants from NASA and AHA. The content is solely the responsibility of the authors and does not necessarily represent the official views of NASA or AHA. In addition, funding was provided by the Graduate Research and Creative Activity fund (GRACA) and Fund for Undergraduate Scholarly experience (FUSE) at the University of Nebraska at Omaha. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

노인의 넘어짐 경험에 따른 보행능력과 균형능력 비교

This study was designed to investigate the effects of falling experience on gait ability and balance ability in the elderly women utilizing new instruments with high validity to measure gait ability and balance in the lower extremities. Forty six elderly women were volunteered to participate in the study as subjects. They were divided into two groups, i.e., falling experienced group(FG: n=24) and non-falling experienced group(NFG: n=22). The collected data were calculated with falling experience group and non-falling experience group utilizing independent t-test with repeated measures. Variables related to physique, gait ability(Temporal parameters and Spatial parameters) and balance ability were measured and compared between the two groups. There was no significant difference between the two groups in all variables of step time, gait cycle time, single support time, double support time, ambulation time, velocity, and mean normalized velocity. in the case of spatial parameters, step length(left, right), stride length(left), step/extremity ratio(left), and funcional ambulatory profiles of gait, were significantly lower in FG than NFG. In addition, FG showed signifiantly lower. in the case of level 2, there was a significant differencce in overall, Anterior･Posterior, Medial･Lateral. in level 4, there was a significant difference between Medial･Lateral. it was concluded that low step length, stride length, funcional ambulatory profiles due to the experience of falling, and a decrease in balance ability on unstable ground. Therefore, the results of this study are expected to be helpful as basic data for constructing an exercise program for improving spatial walking ability and balance ability on unstable ground in planning an exercise program for preventing falls in elderly women.

Rapid and inexpensive voltammetric detection of ochratoxin A in wheat matrices

Produced as toxic metabolites by fungi, mycotoxins, such as ochratoxin A (OTA), contaminate grain and animal feed and cause great economic losses. Herein, we report the fabrication of an electrochemical sensor consisting of an inexpensive and label-free carbon black-graphite paste electrode (CB-G-CPE), which was fully optimized to detect OTA in durum wheat matrices using differential pulse voltammetry (DPV). The effect of carbon paste composition, electrolyte pH and DPV parameters were studied to determine the optimum conditions for the electroanalytical determination of OTA. Full factorial and central composite experimental designs (FFD and CCD) were used to optimize DPV parameters, namely pulse width, pulse height, step height and step time. The developed electrochemical sensor successfully detected OTA with detection and quantification limits equal to 57.2 nM (0.023 µg mL−1) and 190.6 nM (0.077 µg mL−1), respectively. The accuracy and precision of the presented CB-G-CPE was used to successfully quantify OTA in real wheat matrices. This study presents an inexpensive and user-friendly method with potential applications in grain quality control.

Asymmetry measures for quantification of mechanisms contributing to dynamic stability during stepping-in-place gait.

The goal of this study is to introduce and to motivate the use of new quantitative methods to improve our understanding of mechanisms that contribute to the control of dynamic balance during gait. Dynamic balance refers to the ability to maintain a continuous, oscillating center-of-mass (CoM) motion of the body during gait even though the CoM frequently moves outside of the base of support. We focus on dynamic balance control in the frontal plane or medial-lateral (ML) direction because it is known that active, neurally-mediated control mechanisms are necessary to maintain ML stability. Mechanisms that regulate foot placement on each step and that generate corrective ankle torque during the stance phase of gait are both known to contribute to the generation of corrective actions that contribute to ML stability. Less appreciated is the potential role played by adjustments in step timing when the duration of the stance and/or swing phases of gait can be shortened or lengthened to allow torque due to gravity to act on the body CoM over a shorter or longer time to generate corrective actions. We introduce and define four asymmetry measures that provide normalized indications of the contribution of these different mechanisms to gait stability. These measures are 'step width asymmetry', 'ankle torque asymmetry', 'stance duration asymmetry', and 'swing duration asymmetry'. Asymmetry values are calculated by comparing corresponding biomechanical or temporal gait parameters from adjacent steps. A time of occurrence is assigned to each asymmetry value. An indication that a mechanism is contributing to ML control is obtained by comparing asymmetry values to the ML body motion (CoM angular position and velocity) at the time points associated with the asymmetry measures. Example results are demonstrated with measures obtained during a stepping-in-place (SiP) gait performed on a stance surface that either remained fixed and level or was pseudorandomly tilted to disturb balance in the ML direction. We also demonstrate that the variability of asymmetry measures obtained from 40 individuals during unperturbed, self-paced SiP were highly correlated with corresponding coefficient of variation measures that have previously been shown to be associated with poor balance and fall risk.

Physical Activity, but Not Glycaemic Load, Is Associated with Lower Real-Time Glycaemic Control in Free-Living Women with Gestational Diabetes Mellitus.

Maintaining blood glucose within the target range is the primary treatment goal for women with gestational diabetes mellitus (GDM). Foods with low glycaemic loads are recommended in clinical practice; however, the relative importance of other key lifestyle variables is unexplored. This pilot study explored the associations of glycaemic load, carbohydrates and physical activity parameters on blood glucose concentrations in free-living women with GDM. Twenty-nine women (28-30 weeks gestation, 34 ± 4 years) with GDM were enrolled. Continuous glucose monitoring, physical activity (ActivPAL inclinometer) and dietary intake and dietary quality were measured concurrently for 3 days. Pearson correlation analyses determined the association between glucose levels and lifestyle variables. Despite all receiving the same nutrition education, only 55% of women were following a low glycaemic load diet with a large range of carbohydrate intakes (97-267 g/day). However, the glycaemic load did not correlate with 3-hr postprandial glucose (r2 = 0.021, p = 0.56) or 24-h glucose iAUC (r2 = 0.021, p = 0.58). A significant relationship between total stepping time and lower 24-h glucose iAUC (r2 = 0.308, p = 0.02) and nocturnal glucose (r2 = 0.224, p = 0.05) was found. In free-living women with diet-controlled GDM, more physical activity, i.e., steps accumulated across the day, may be a simple and effective strategy for improving maternal blood glucose concentrations.

Accelerated Synthesis of Ordered Mesoporous Carbons Using Plasma.

Conventional ordered mesoporous carbon (OMC) production usually requires long processing times in the carbonization step to achieve desired temperatures through controlled ramps. To enable expedited materials discovery, developing advanced manufacturing capability with significantly improved throughput is highly desired. Current approaches for accelerating the synthesis of OMCs include using microwave and Joule heating. However, both methods rely on the introduction of additional components, such as microwave absorbers and electrically conductive agents, within the bulk materials to impart the ability to reach high carbonization temperatures. This work demonstrates accelerated synthesis and functionalization of OMCs through the use of a dielectric barrier discharge plasma, where carbonization can be accomplished within 15 min using 30 W plasma sources, representing more than an order of magnitude increase in polymer-to-carbon conversion kinetics compared to that of a traditionally pyrolyzed analogue. Particularly, the ability of performing rapid carbonization without the use of additional substrates within the OMC precursor systems is advantageous. A systematic investigation of how plasma power, time, and gas atmosphere impact the resulting OMC pore textures and properties is performed, demonstrating the broad applicability of plasma-enabled carbonization methods. Furthermore, we demonstrate that the plasma treatment strategy can be extended to incorporate heteroatoms into the carbon framework by introducing ammonia gas, resulting in OMCs with a nitrogen content up to 4.7 at %, as well as non-Pluronic templating systems for synthesizing OMC with pore sizes larger than 10 nm. As employing a plasma source for materials pyrolysis is an industrially relevant approach, our system can be extended toward scaled synthesis of OMCs with much faster production rates.

Early spontaneous movements and spatiotemporal gait characteristics in preterm children.

This study aimed to analyze spatiotemporal gait characteristics of preterm children from 3 to 4years of age according to different gestational age groups and to examine the relationship between the detailed general movements assessment and spatiotemporal gait characteristics. A total of 74 preterm children, 32 extremely preterm and very preterm (EP-VP, < 32weeks gestational age) and 42 moderate to late preterm (MLP, 32 to < 37weeks gestational age), were included in this prospective study, along with 38 term children. Early spontaneous movements of preterm children were assessed from videos at 9-20weeks post-term according to the general movements assessment, which determines the Motor Optimality Score-Revised (MOS-R). The spatiotemporal gait characteristics of all children were evaluated using the GAITRite®electronicwalkway at self-selected walking speeds. EP-VP children walked with shorter step lengths (p = 0.039), and MLP children walked with greater step length variability (p = 0.003) than their term peers. The MOS-R results were related to step length (r = 0.36, p = 0.042), step length variability (r = -0.56, p = 0.001), and base of support (r = -0.37, p = 0.038) in EP-VP children. The MOS-R subcategories, age-adequate movement repertoire, and postural patterns were related to some of the spatiotemporal gait characteristics, including step length, step length variability, and base of support (p < 0.05). Conclusion: EP-VP and MLP children might catch up to their term peers at 3 to 4years of age in terms of most gait parameters. In addition to the MOS-R, age-adequate movement repertoire and postural patterns of preterm children without cerebral palsy in early life may be a marker of later neurodevelopmental dysfunction. What is Known: • Preterm children walk with a wider step width, a greater step length asymmetry and step time, and a shorter stride length at 18 to 22 months of age compared with term children at aself-selected speed, while these differences disappear in children 4.5-5 years old and older. What is New: • Early spontaneous movements were related to some spatiotemporal gait characteristics. • Preterm children might catch up to term children at 3-4 years of age in spatiotemporal gait characteristics while walking at a self-selected speed.

A normative study of the gait features measured by a wearable inertia sensor in a healthy old population

BackgroundGait function impairments are associated with the risk of various medical conditions in older adults. As gait function declines with advancing age, normative data are required for proper interpretation of gait function in older adults. Research purposeThis study aimed to construct age-stratified normative data of non-dimensionally normalized temporal and spatial gait features in healthy older adults. MethodsWe recruited 320 community-dwelling healthy adults aged 65 years or older from two prospective cohort studies. We stratified them into four age groups (65–69, 70–74, 75–79, and 80–84 years). Each age group comprised 40 men and 40 women. We obtained six gait features (cadence, step time, step time variability, step time asymmetry, gait speed, and step length) using a wearable inertia measurement unit attached on the skin overlying L3-L4 on the back. To mitigate the influence of body shape, we non-dimensionally normalized the gait features into unitless values using height and gravity. ResultThe effect of age group was significant in all raw gait features (p < 0.001 for step time variability, speed and step length; p < 0.05 for cadence, step time and step time asymmetry), and that of sex was significant in the five raw gait features, except for step time asymmetry(p < 0.001 for cadence, step time, speed, and step length; p < 0.05 for step time asymmetry). When gait features were normalized, the effect of age group remained (p < 0.001 for all gait features), whereas that of sex disappeared (p > 0.05 for all gait features). SignificanceOur dimensionless normative data on gait features may be useful in comparative studies of gait function between sexes or ethnicities with different body shapes.