Walking Step Research Articles

Paradigmatic examples for testing models of optical light polarization by spheroidal dust

We present a general framework on how the polarization of radiation due to scattering, dichroic extinction, and birefringence of aligned spheroidal dust grains can be implemented and tested in 3D Monte Carlo radiative transfer (MCRT) codes. We derive a methodology for solving the radiative transfer equation governing the changes of the Stokes parameters in dust-enshrouded objects. We utilize the Müller matrix and the extinction, scattering, linear, and circular polarization cross sections of spheroidal grains as well as electrons. An established MCRT code is used, and its capabilities are extended to include the Stokes formalism. We compute changes in the polarization state of the light by scattering, dichroic extinction, and birefringence on spheroidal grains. The dependency of the optical depth and the albedo on the polarization is treated. The implementation of scattering by spheroidal grains both for random walk steps as well as for directed scattering (peel-off) are described. The observable polarization of radiation of the objects is determined through an angle binning method for photon packages that leaves the model space as well as through an inverse ray-tracing routine for the generation of images. We present paradigmatic examples for which we derive analytical solutions of the optical light polarization by spheroidal dust particles. These tests are suited for benchmark verification of MCPOLand other such codes and allow the numerical precision reached by these codes to be quantified. We demonstrate that MCPOLis in excellent agreement (within ~0.1%) of the Stokes parameters when compared to the analytical solutions.

Knee kinetics and the medial femoral cartilage cross-sectional area response to loading in indviduals with anterior cruciate ligament reconstruction

BackgroundUltrasonography is capable of detecting morphological changes in femoral articular cartilage cross-sectional area in response to an acute bout of walking; yet, the response of femoral cartilage cross-sectional area varies between individuals. It is hypothesized that differences in joint kinetics may influence the response of cartilage to a standardized walking protocol. Therefore, the study purpose was to compare internal knee abduction and extension moments between individuals with anterior cruciate ligament reconstruction who demonstrate an acute increase, decrease, or unchanged medial femoral cross-sectional area response following 3000 steps. MethodsThe medial femoral cartilage in the anterior cruciate ligament reconstructed limb was assessed with ultrasonography before and immediately following 3000 steps of treadmill walking. Knee joint moments were calculated in the anterior cruciate ligament reconstructed limb and compared between groups throughout the stance phase of gait using linear regression and functional, mixed effects waveform analyses. FindingsNo associations between peak knee joint moments and the cross-sectional area response were observed. The group that demonstrated an acute cross-sectional area increase exhibited 1) lower knee abduction moments in early stance in comparison to the group that exhibited a decreased cross-sectional area response; and 2) greater knee extension moments in early stance in comparison to the group with an unchanged cross-sectional area response. InterpretationThe propensity of femoral cartilage to acutely increase cross-sectional area in response to walking is consistent with less-dynamic knee abduction and knee extension moment profiles.

Early postoperative step count and walking time have greater impact on lower limb fracture outcomes than load-bearing metrics

IntroductionWeight-bearing protocols for rehabilitation of lower extremity fractures are the gold standard despite not being data-driven. Additionally, current protocols are focused on the amount of weight placed on the limb, negating other patient rehabilitation behaviors that may contribute to outcomes. Wearable sensors can provide insight into multiple aspects of patient behavior through longitudinal monitoring. This study aimed to understand the relationship between patient behavior and rehabilitation outcomes using wearable sensors to identify the metrics of patient rehabilitation behavior that have a positive effect on 1-year rehabilitation outcomes. MethodsProspective observational study on 42 closed ankle and tibial fracture patients. Rehabilitation behavior was monitored continuously between 2 and 6 weeks post-operative using a gait monitoring insole. Metrics describing patient rehabilitation behavior, including step count, walking time, cadence, and body weight per step, were compared between patient groups of excellent and average rehabilitation outcomes, as defined by the 1-year Patient Reported Outcome Measure Physical Function t-score (PROMIS PF). A Fuzzy Inference System (FIS) was used to rank metrics based on their impact on patient outcomes. Additionally, correlation coefficients were calculated between patient characteristics and principal components of the behavior metrics. ResultsTwenty-two patients had complete insole data sets, and 17 of which had 1-year PROMIS PF scores (33.7 ± 14.5 years of age, 13 female, 9 in Excellent group, 8 in Average group). Step count had the highest impact ranking (0.817), while body weight per step had a low impact ranking (0.309). No significant correlation coefficients were found between patient or injury characteristics and behavior principal components. General patient rehabilitation behavior was described through cadence (mean of 71.0 steps/min) and step count (logarithmic distribution with only ten days exceeding 5,000 steps/day). ConclusionStep count and walking time had a greater impact on 1-year outcomes than body weight per step or cadence. The results suggest that increased activity may improve 1-year outcomes for patients with lower extremity fractures. The use of more accessible devices, such as smart watches with step counters combined with patient reported outcome measures may provide more valuable insights into patient rehabilitation behaviors and their effect on rehabilitation outcomes.

Harvesting Kinetic Energy of Footsteps to Generate Electricity

Energy and power are the basic needs of this modern world. The Energy demand is increasing every day. On the other hand, a lot of energy resources are depleted and wasted. Suggestion for using the waste energy of leg power with a person movement is very important in populated countries like India where are roads, railway stations, bus stands, temples etc. crowded with millions of people moving around. This unit energy is wasted. If this energy allowed its use will be a great invention. In this project we convert unconventional from a mere pedestrian step into electrics energy. This project uses a simple drive mechanism such as rack and pinion assembly. The control mechanism carries rack and pinion and DC generator for output. In this project we generate electricity as an unconventional method simply by walking or running steps. A non-conventional energy system is very essential at this time to our nation. Unconventional energy using the foot step needs no fuel input to produce electricity Power supply. In this project, a simple drive mechanism such as a rack and pinion assembly and chain drive mechanism are used for the production of energy using the obtained power it converts to electric when walking up the stairs energy using mechanical L9 systems. Generated energy is stored using a battery and it is used for activation of connected loads. It is one of the compact and efficient systems for generating electricity that can be easily installed in many regions.

Association between device-measured stepping behaviors and cardiometabolic health markers in middle-aged women: The Australian Longitudinal Study on Women's Health.

The associations between different types and contexts of stepping behaviors and cardiometabolic (CM) health markers are unclear. This study aimed to examine the associations of daily total, walking, stair, incidental and purposeful steps with cardiometabolic risk. A total of 943 women (mean age ± SD = 44.1 ± 1.6 years) from the Australian Longitudinal Study on Women's Health (ALSWH) were included in this cross-sectional study. Daily total, walking, stair, incidental, and purposeful steps were measured using thigh-worn accelerometry. Outcomes comprised of CM markers of adiposity, blood pressure, resting heart rate, lipids, glycaemia, and the composite CM score. We used generalized linear modeling and multiple linear regression to assess the associations. We observed that all stepping behaviors were beneficial to CM health, for example, compared to the lowest quartile (Q1), the change of the composite CM score across low to high quartile of purposeful steps was -0.12 (Q2, 95% CI: -0.41, 0.17), -0.16 (Q3, -0.46, 0.14), and -0.36 (Q4, -0.66, -0.05). Stair steps showed linear associations with blood pressure and adiposity biomarkers, for example, the change of quartile of waist circumference was -1.45 cm (Q2, -4.35, 1.44), -3.56 cm (Q3, -6.52, -0.60), and -7.08 cm (Q4, -10.31, -3.86). Peak 30-min walking intensity showed independent association with adiposity biomarkers (p linear < 0.001 and p = 0.002 for waist circumference and BMI, respectively). Our study showed that all stepping forms were beneficial to CM health. Higher stair steps and peak 30-min walking cadence were associated with a steep decline of adiposity biomarkers. Purposeful steps showed more consistent associations with CM biomarkers than incidental steps.

Self-Powered DNAzyme Walker Enables Dual-Mode Biosensor Construction for Electrochemiluminescence and Electrochemical Detection of MicroRNA.

Herein, an electrochemiluminescence (ECL) and electrochemical (EC) dual-mode biosensor platform with a self-powered DNAzyme walking machine was established for accurate and sensitive detection of miRNA-21. By employing a magnesium ion (Mn2+)-dependent DNAzyme cleavage cycling reaction, the walking machine was built by assembling DNAzyme walking strands and ferrocene (Fc)-labeled substrate strands on the Au nanoparticles and graphitic carbon nitride nanosheet (g-C3N4 NS)-covered electrode. The DNAzyme walking strand was first prohibited by a blocker strand. After the addition of target miRNA-21 and Mn2+, the DNAzyme walker could be activated and produce autonomous movements along the electrode track fueled by Mn2+-dependent DNAzyme-catalyzed substrate cleavage without additional energy supply. Notably, each walking step resulted in the cleavage of a substrate strand and the release of a Fc-labeled DNA strand fragment, allowing us to acquire an extreme ECL signal recovery of g-C3N4 inhibited by Fc. Meanwhile, numerous Fc-labeled DNA fragments escaped from the surface of the electrode, directly producing an obvious decrease in the square wave voltammetry (SWV) signal from Fc on the same sensing platform. This work not only avoided difficultly assembling various signal indicators but also significantly improved the sensitivity through using self-powered DNAzyme-walker amplification. Moreover, the proposed design employed the same reaction to produce two signal output modes, which could eliminate the interference from diverse reactive pathways on the outcome to mutually improve the accuracy. Therefore, the dual-mode miRNA-21 biosensor exhibited wide detection ranges of 100 aM to 100 nM with low detection limits of 54.3 and 78.6 aM by ECL and SWV modes, respectively, which provided an efficient and universal biosensing approach with extensive applications in early disease diagnosis and bioanalysis.

Daily steps and stepping cadence increase one-year following prosthesis osseointegration in people with lower-limb amputation

Purpose People with lower-limb loss participate in less physical activity than able-bodied individuals, which increases the mortality risk and incidence of metabolic syndromes. This study evaluated the effect of lower-limb prosthesis osseointegration on physical activity, including daily steps and stepping cadence. Methods Free-living walking activity was assessed from 14 patients scheduled to undergo prosthesis osseointegration at two time points (within 2 weeks prior to osseointegration surgery and 12-months following). Daily step count, stepping time, number of walking bouts, average step cadence per bout, maximum step cadence per bout, and time spent in bands of step cadence were compared before and after osseointegration. Results Twelve months after prosthesis osseointegration, participants increased daily steps, daily stepping time, average step cadence, and maximum cadence per walking bout compared to pre-osseointegration. Conclusions Participants engaged in more daily steps, higher stepping cadence, and longer bouts at higher cadence one year following osseointegration compared to when using a socket prosthesis. As a novel intervention that is becoming more common, it is important to understand walking activity outcomes as these are critical for long-term health.

Effect of selective percutaneous myofascial lengthening and functional physiotherapy on walking in children with cerebral palsy: Three-dimensional gait analysis assessment

BackgroundWalking is the most affected motor function in children with cerebral palsy (CP). Orthopaedic surgery is regularly used to improve ambulation in children with CP. Selective Percutaneous Myofascial Lengthening (SPML) is considered the state-of-the art technique for surgical lengthening of spastic/contracted muscles in CP. The purpose of this study was to investigate the effect of combined SPML surgery and postoperative functional physiotherapy on gait function and characteristics of children with spastic cerebral palsy (CP). MethodsTwenty-six children with spastic CP, aged 5–7 years, Gross Motor Function Classification System (GMFCS) levels II (n = 6), III (n = 12) and IV (n = 8) participated in a quasi-experimental one-group pretest-posttest study with a 9-month follow-up. The Global Motion Graph Deviation Index (MGDI) (including MGDI sub-indices of each joint in each plane of motion) and spatiotemporal parameters of a three-dimensional kinematic gait analysis were used to assess the gait function and characteristics, respectively. ResultsNine months following SPML and functional physiotherapy, statistically significant improvements (p < 0.05) were noted in the Global MGDI, the MGDIs of sagittal plane knee and ankle motion analysis graphs, and the four most common spatiotemporal measures of gait: walking velocity, stride length, step length, and cadence. ConclusionChildren with spastic CP seem to gain better overall gait function following SPML procedure and functional physiotherapy, by achieving higher walking velocity, longer stride length and step length, and faster cadence. Further studies with control group and longer follow-up three-dimensional gait analyses are warranted to validate these positive results.

Speeding up: Discrete mediolateral perturbations increased self-paced walking speed in young and older adults

BackgroundIn uncertain environments and with increasing age humans often walk slower while taking shorter, quicker, and wider steps, reflective of a cautious gait. Understanding when humans opt to use a cautious gait and the differences in gait strategies used as people age could be examined with perturbations on a self-paced treadmill that allows participants to adjust their walking speed. Adding varying degrees of unpredictability, an inherent element of real-world walking could also improve understanding of when specific gait strategies are used. Research questionWe investigated how healthy young and older adults adjust their gait strategies when responding to perturbations of varying unpredictability. We hypothesized that more unpredictable perturbations would produce more cautious gait strategies and be more pronounced in older adults than young adults. MethodsTen young and ten older adults walked on a self-paced treadmill with discrete mediolateral treadmill shift perturbations. We changed the shift magnitude and/or the timing of the perturbations during the gait cycle to vary perturbation unpredictability. We analyzed walking speed and step kinematics from treadmill and motion capture data. ResultsSurprisingly, participants walked faster not slower for the conditions with perturbations. Even more surprising older adults walked faster overall than young adults. As expected, participants took faster and wider steps for the most unpredictable perturbation but also took longer steps which was not expected. Step kinematic variability and average step width also increased as perturbation unpredictability increased suggesting that the more unpredictable conditions demanded greater balance control. Additionally, older adults had greater step kinematic variability, highlighted further using detrended step length variability, compared to young adults SignificanceOverall, these findings provide new insights about gait strategies and suggest that perturbations such as discrete mediolateral treadmill shifts can potentially be designed to encourage participants to walk faster if it is beneficial.

Quantitative measures of motor development in Angelman syndrome.

Angelman Syndrome is a rare neurodevelopmental disorder characterized by developmental delay, lack of speech, seizures, intellectual disability, characteristic behavior, and movement disorders. Clinical gait analysis provides the opportunity for movement quantification to investigate an observed maladaptive change in gait pattern and offers an objective outcome of change. Pressure-sensor-based technology, inertial and activity monitoring, and instrumented gait analysis (IGA) were employed to define motor abnormalities in Angelman syndrome. Temporal-spatial gait parameters of persons with Angelman Syndrome (pwAS) show deficiencies in gait performance through walking speed, step length, step width, and walk ratio. pwAS walk with reduced step lengths, increased step width, and greater variability. Three-dimensional motion kinematics showed increased anterior pelvic tilt, hip flexion, and knee flexion. PwAS have a walk ratio more than two standard deviations below controls. Dynamic electromyography showed prolonged activation of knee extensors, which was associated with a decreased range of motion and the presence of hip flexion contractures. Use of multiple gait tracking modalities revealed that pwAS exhibit a change in gait pattern to a flexed knee gait pattern. Cross-sectional studies of individuals with AS show a regression towardthis maladaptive gait pattern over developmentinpwASages4-11. PwAS unexpectedly did not have spasticity associated with change in gait pattern. Multiple quantitative measures of motor patterning may offer early biomarkers of gait decline consistent with critical periods of intervention, insight into appropriate management strategies, objective primary outcomes, and early indicators of adverse events.

On free energy barriers in Gaussian priors and failure of cold start MCMC for high-dimensional unimodal distributions.

We exhibit examples of high-dimensional unimodal posterior distributions arising in nonlinear regression models with Gaussian process priors for which Markov chain Monte Carlo (MCMC) methods can take an exponential run-time to enter the regions where the bulk of the posterior measure concentrates. Our results apply to worst-case initialized ('cold start') algorithms that are local in the sense that their step sizes cannot be too large on average. The counter-examples hold for general MCMC schemes based on gradient or random walk steps, and the theory is illustrated for Metropolis-Hastings adjusted methods such as preconditioned Crank-Nicolson and Metropolis-adjusted Langevin algorithm. This article is part of the theme issue 'Bayesian inference: challenges, perspectives, and prospects'.

RadarPDR: Radar-Assisted Indoor Pedestrian Dead Reckoning

Pedestrian dead reckoning (PDR) is the critical component in indoor pedestrian tracking and navigation services. While most of the recent PDR solutions exploit in-built inertial sensors in smartphones for next step estimation, due to measurement errors and sensing drift, the accuracy of walking direction, step detection, and step length estimation cannot be guaranteed, leading to large accumulative tracking errors. In this paper, we propose a radar-assisted PDR scheme, called RadarPDR, which integrates a frequency-modulation continuous-wave (FMCW) radar to assist the inertial sensors-based PDR. We first establish a segmented wall distance calibration model to deal with the radar ranging noise caused by irregular indoor building layouts and fuse wall distance estimation with acceleration and azimuth signals measured by the inertial sensors of a smartphone. We also propose a hierarchical particle filter(PF) together with an extended Kalman filter for position and trajectory adjustment. Experiments have been conducted in practical indoor scenarios. Results demonstrate that the proposed RadarPDR is efficient and stable and outperforms the widely used inertial sensors-based PDR scheme.

Abstract P6-05-33: Distress Reduction and Physical Activity Enhancement by Mobile Support Group in Breast Cancer Survivors: a randomized controlled study

Abstract Purpose Improving physical activity (PA) and reducing mental distress are important issues in the treatment of cancer survivors. This study aimed to investigate the effect of a mobile app-based community on enhancing PA and decreasing distress in breast cancer survivors. Methods We conducted a single-center, prospective, non-blinded, randomized controlled study. Subjects who got breast cancer surgery were allocated to a control group or a app-based community group (intervention) where members were able to share their daily physical activities. Daily walk steps and weekly distress scores using app-based Distress Thermometer (DT) questionnaires were collected from participants for 24 weeks. To examine the differences in levels of distress and weekly step counts for 6 months, we used a t-test method and multivariable regression modeling. Results From Jan 2019 to Apr 2020, a total of 202 participants were enrolled in this study. The intervention group showed a significant increase in weekly steps by 4,496 for 6 months (p &amp;lt; 0.001). The participants in the intervention group showed a significantly lower rate of above mild distress (DT≥3, beta[B] = -0.731, p &amp;lt; 0.001) and above moderate distress (DT≥5, B = -0.558, p &amp;lt; 0.001) compared to those in the control group for 6 months. Conclusions The mobile app-based community is an effective and less resource-intensive tool to increase PA and decrease distress in breast cancer survivors. Citation Format: Il-Yong Chung, Miyeon Jung, Sae Byul Lee, Jong Won Lee, Sei Hyun Ahn, Haekwon Chung. Distress Reduction and Physical Activity Enhancement by Mobile Support Group in Breast Cancer Survivors: a randomized controlled study [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-33.

Outcome of bracing vs. surgical treatment in adolescents with idiopathic scoliosis based on device measured daily physical activity: a prospective pilot study.

Adolescent idiopathic scoliosis (AIS) can be treated with bracing or surgery, which may affect patient's physical activity (PA). However, there are limited objective assessments of PA in patients with AIS. This study aims to compare the outcome of spinal bracing vs. surgery in patients with AIS based on a device that measured daily PA. In total 24 patients with AIS participated, including 12 patients treated with bracing and 12 with spinal surgery. Daily PA was measured throughout 4 consecutive days using four tri-axial accelerometers and patient-reported functional status was reported using the SRS-22 questionnaire. The participants were assessed both before the treatment and after treatment at a 12-month follow-up. Patients with AIS had no significant change in their PA levels at the 12-month follow-up after surgical correction. On the contrary, patients with AIS following a year-long bracing treatment had significantly reduced time spent active ( P = 0.04) with an average reduction in walking steps by 2137 steps/day ( P = 0.005). There was no significant difference in function, pain, self-image and mental health domains following both treatments, as reported by the SRS-22. There was a significant improvement in satisfaction for both treatment groups ( P ≤ 0.02). Significantly reduced PA and increased sedentary time are reported in patients with AIS following bracing treatment. An objective PA assessment is recommended to track the effect of scoliosis treatment on PA. Patients with AIS should be actively encouraged to achieve and maintain their recommended daily PA levels irrespective of the type of treatment. Level of evidence: Level II.

Impact of ambient air pollution on physical activity and sedentary behavior in children

BackgroundExposure to air pollution has become a serious environmental issue affecting children’s health and health-related behavior in China. Previous studies have focused on the associations between air pollution and physical activity among adults; however, few have examined the relationship between air pollution and health-related behavior among children, which are particularly susceptible population subgroups. The present study aims to examine the impact of air pollution on daily physical activity (PA) and sedentary behavior (SB) among children in China.MethodsPA and SB data were collected by actiGraph accelerometers for eight consecutive days. PA and SB data from 206 children were matched to daily air pollution obtained from the Ministry of Environmental Protection of the People’s Republic of China, including the average daily air quality index (AQI), PM2.5 (µg/m³), and PM10 (µg/m³). Associations were estimated using linear individual fixed-effect regressions.ResultsA 10-unit increase in daily AQI was associated with a reduction in daily PA by 5.94 (95% confidence interval [CI] = -8.79, -3.08) minutes of moderate to vigorous physical activity (MVPA) and 229.82 (95% CI = -345.35, -114.28) walking steps and an increase in daily SB by 15.77 (95% CI = 9.01, 22.53) minutes. A 10 µg/m³ increase in air pollution concentration in daily PM2.5 was associated with a reduction in daily PA by 7.51 (95% CI = -11.04, -3.97) minutes of MVPA, 295.69 (95% CI = -438.46, -152.92) walking steps and an increase in daily SB by 21.12 (95% CI = 12.77, 29.47) minutes. A 10 µg/m³ increase in air pollution concentration in daily PM10 was associated with a reduction in daily PA by 13.18 (95% confidence interval [CI] = -15.98, -10.37) minutes of MVPA, 518.34 (95% CI = -631.77, -404.91) walking steps and an increase in daily SB by 19.87 (95% CI = 13.10, 26.64) minutes.ConclusionAir pollution may discourage physical activity and increase sedentary behavior among children. Policy interventions are needed to reduce air pollution and develop strategies to decrease risks to children’s health.

The Potential for Effect of a Six-Week Training Program for Gait Aid Use in Older People with Dementia with Unsteadiness of Gait: A Pilot Study

This study examined the potential for effect of a six-week gait aid training program for people with dementia on spatiotemporal gait outcomes, perception of use, and falls with gait aid use. The program utilised four 30-min physiotherapy home visits, scheduled at weeks 1/2/3/6, and was enhanced by carer-supervised practice. Falls and the physiotherapist's clinical judgement of participants achieving safe gait aid use during and after the program were described. Perception ratings at each visit were measured using Likert scales which, along with the spatiotemporal outcomes using the gait aid (Time-Up-and-Go-Test, 4-m-walk-test, Figure-of-8-Walk-Test with/without a cognitive task) at weeks 1 and 6, and at weeks 6 and 12 (6-week post-program), were examined with ordinal logistic regression analyses. Twenty-four community-dwelling older people with dementia and their carers participated. Twenty-one (87.5%) older people achieved safe gait aid use. Twenty falls occurred, and only one faller was using their gait aid when they fell. Walking speed, step length, and cadence significantly improved when walking with the gait aid at week 6 compared with week 1. No significant improvements in spatiotemporal outcomes were retained at week 12. Physiotherapists were more likely to agree that gait aid use had improved walking safety among older people with dementia with subsequent training visits. Larger studies of the gait aid training program are needed for this clinical group.

How to Realize Efficient and Scalable Graph Embeddings via an Entropy-Driven Mechanism

Graph embedding is becoming widely adopted as an efficient way to learn graph representations required to solve graph analytics problems. However, most existing graph embedding methods, owing to computation-efficiency challenges for large-scale graphs, generally employ a one-size-fits-all strategy to extract information, resulting in a large amount of redundant or inaccurate representations. In this work, we propose HuGE+, an efficient and scalable graph embedding method enabled by an entropy-driven mechanism. Specifically, HuGE+ leverages hybrid-property heuristic random walk to capture node features, which considers both information content of nodes and the number of common neighbors in each walking step. More importantly, to guarantee information effectiveness of sampling, HuGE+ adopts two heuristic methods to decide the random walk length and the number of walks per node, respectively. Extensive experiments on real-world graphs demonstrate that HuGE+ achieves both efficiency and performance advantages over recent popular graph embedding approaches. For three downstream graph tasks, our approach not only offers >10% average gains, but also exhibits 23×–127× speedup over existing sampling-based methods. In addition, HuGE+ significantly reduces memory footprint by an average of 68.9%, facilitating training for billion-node-scale graph embeddings.

STEPPING BEYOND COUNTS, FEASIBILITY OF PASSIVELY COLLECTED QUALITATIVE GAIT METRICS USING A SMARTPHONE-BASED CARE MANAGEMENT PLATFORM FOLLOWING TOTAL JOINT ARTHROPLASTY

Advances in algorithms developed with sensor data from smart phones demonstrates the capacity to passively collect qualitative gait metrics. The purpose of this feasibility study was to assess the recovery of these metrics following joint reconstruction. A secondary data analysis of an ethics approved global, multicenter, prospective longitudinal study evaluating gait quality data before and after primary total knee arthroplasty (TKA, n=476), partial knee arthroplasty (PKA, n=139), and total hip arthroplasty (THA, n=395). A minimum 24 week follow-up was required (mean 45±12, range 24 - 78). Gait bouts and gait quality metrics (walking speed, step length, timing asymmetry, and double support percentage) were collected from a standardized smartphone operating system. Pre- and post-operative values were compared using paired-samples t-tests (p&lt;0.05).A total of 595 females and 415 males with a mean age of 61.9±9.3 years and mean BMI of 30.2±6.1 kg/m2 were reviewed. Walking speeds were lowest at post-operative week two (all, p&lt;.001). Speeds exceeded pre-operative means consistently by week 21 (p=0.015) for PKA, and week 13 (p=0.007) for THA. The average weekly step length was lowest in post-operative week two (all, p&lt;0.001). PKA and THA cases achieved pre-operative step lengths by week seven (p=0.064) and week 9 (p=0.081), respectively. The average weekly gait asymmetry peaked at week two post-operatively (all, p &lt;0.001). Return to pre-operative baseline asymmetry was achieved by week 11 (p=0.371) for TKA, week six (p=0.541) for PKA, and week eight (p=.886) for THA. Double limb support percentages peaked at week two (all, p&lt;0.001) and returned to pre-operative levels by week 24 (p=0.089) for TKA, week 12 (p=0.156) for PKA, and week 10 (p=0.143) for THA.Monitoring gait quality in real-world settings following joint reconstruction using smartphones is feasible, and may provide the advantage of removing the Hawthorne effect related to typical gait assessments and in-clinic observations.

Development of a novel footwear based power harvesting system

Daily activities such as walking and running possess abundant amount of energy, which is usually wasted and have the potential to be harvested. Especially, the energy generated from footsteps, if tapped appropriately, may be useful for charging electronic devices such as cell phones, wearables, and medical devices. In this study, the kinetic energy from footsteps was captured using a novel six-layered compartmental insole design with embedded piezoelectric transducers. This system was fabricated using additive manufacturing techniques and evaluated for its capabilities to charge a battery while walking and running. The charging performance was estimated initially for 6000 walking steps and extended to approximately 67,000 simulated running steps to fully charge the battery. A range of transducer arrangements were tested, indicating better power generation from the parallel combinations compared to series. Across gait activities, running was observed to lead to better coordination between the piezoelectric transducers and generation of higher power, compared to in walking. While very high amount of electrical power was not realized, the device performance was found to be satisfactory to charge low power rated wearable lifestyle electronic or medical devices. The findings from this work is anticipated to provide novel insights for power harvesting from human gait.

Effects of Face-to-Face and eHealth Blended Interventions on Physical Activity, Diet, and Weight-Related Outcomes among Adults: A Systematic Review and Meta-Analysis.

An increasing number of studies are blending face-to-face interventions and electronic health (eHealth) interventions to jointly promote physical activity (PA) and diet among people. However, a comprehensive summary of these studies is lacking. This study aimed to synthesize the characteristics of blended interventions and meta-analyze the effectiveness of blended interventions in promoting PA, diet, and weight-related outcomes among adults. Following the PRISMA guidelines, PubMed, SPORTDiscus, PsycINFO, Embase, and Web of Science were systematically searched to identify eligible articles according to a series of inclusion criteria. The search was limited to English language literature and publication dates between January 2002 and July 2022. Effect sizes were calculated as standardized mean difference (SMD) for three intervention outcomes (physical activity, healthy diet, and weight-related). Random effect models were used to calculate the effect sizes. A sensitivity analysis and publication bias tests were conducted. Of the 1561 identified studies, 17 were eligible for the systematic review. Studies varied in participants, intervention characteristics, and outcome measures. A total of 14 studies were included in the meta-analyses. There was evidence of no significant publication bias. The meta-analyses indicated that the blended intervention could lead to a significant increase in walking steps (p < 0.001), total PA level (p = 0.01), and diet quality (p = 0.044), a significant decrease in energy intake (p = 0.004), weight (p < 0.001), BMI (p < 0.001), and waist circumferences (p = 0.008), but had no influence on more moderate-to-vigorous physical activity (MVPA) or fruit and vegetable intake among adults, compared with a control group. The study findings showed that blended interventions achieve preliminary success in promoting PA, diet, and weight-related outcomes among adults. Future studies could improve the blended intervention design to achieve better intervention effectiveness.