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This study addresses the urgent environmental issue of climate change, focusing specifically on the role of local food, which is produced and consumed locally, in helping to reduce carbon emissions by eliminating the need for long-distance transportation. Through quantitative analysis, this study elucidates the potential benefits of environmental impact achieved through the consumption of local food, i.e., the significant reduction in carbon emissions. Specifically, the consumption of local food has been found to yield an annual decrease of 2,421,296 t C O 2 emissions, representing 2.5% of the Republic of Korea's total greenhouse gas emissions from the transportation sector. This reduction further translates into an estimated economic value of USD 54.23 million (KRW 70.5 billion). These findings underscore the potential of local food consumption as a tangible strategy to overcome environmental problems. Moreover, the academic contribution of this study lies in its comprehensive analysis of the economic and empirical impacts of local food consumption on the environment. Moving forward, we propose policies such as supporting local food distribution networks, providing public education on local food, fostering local food industries, and implementing incentives to revitalize local food consumption. [ABSTRACT FROM AUTHOR]

Background: Turning during walking and volitionally modulating walking speed introduces complexity to gait and has been minimally explored. Research question: Howdo the spatiotemporal parameters vary between young adults walking at a normal speed and a slower speed whilemaking 90°, 180°, and 360° turns? Methods: In a laboratory setting, the spatiotemporal parameters of 10 young adults were documented as theymade turns at 90°, 180°, and 360°. A generalized linear model was utilized to determine the effect of both walking speed and turning amplitude. Results: Young adults volitionally reducing their walking speed while turning at different turning amplitudes significantly decreased their cadence and spatial parameters while increasing their temporal parameters. In conditions of slower movement, the variability of certain spatial parameters decreased, while the variability of some temporal parameters increased. Significance: This research broadens the understanding of turning biomechanics in relation to volitionally reducing walking speed. Cadence might be a pace gait constant synchronizing the rhythmic integration of several inputs to coordinate an ordered gait pattern output. Volition might up-regulate or down-regulate this pace gait constant (i.e., cadence) which creates the feeling of modulating walking speed. [ABSTRACT FROM AUTHOR]

Conventional one-time gait analyses do not evaluate walking across more than a few steps, cannot monitor changes longitudinally, and do not reflect performance in real-life environments. To successfully quantify age-related gait decrement, technology that can continuously monitor gait is vital. This study examined the feasibility and validity for participant smartphones to remotely assess gait. In addition, the authors investigated whether smartphone-derived measures could differentiate between young and older adults (fallers and nonfallers). A total of 63 adults completed clinical and gait assessment in the laboratory and donned their smartphones for 3 days in the real-life environment. A custom-built Android application collected triaxial accelerations with spatiotemporal gait measures computed and compared between groups. Across 11 brands and 10 Android versions, smartphone-derived gait parameters were valid. Furthermore, results indicated age-related differences in walking during the 3-day assessment. However, no disparities were found between older adult groups. Smartphone-based evaluations may improve real-life screening of adults with gait deficits. [ABSTRACT FROM AUTHOR]

Lower-limb exoskeletons have the potential to transform the way we move 1-14 , but current state-of-the-art controllers cannot accommodate the rich set of possible human behaviours that range from cyclic and predictable to transitory and unstructured. We introduce a task-agnostic controller that assists the user on the basis of instantaneous estimates of lower-limb biological joint moments from a deep neural network. By estimating both hip and knee moments in-the-loop, our approach provided multi-joint, coordinated assistance through our autonomous, clothing-integrated exoskeleton. When deployed during 28 activities, spanning cyclic locomotion to unstructured tasks (for example, passive meandering and high-speed lateral cutting), the network accurately estimated hip and knee moments with an average R 2 of 0.83 relative to ground truth. Further, our approach significantly outperformed a best-case task classifier-based method constructed from splines and impedance parameters. When tested on ten activities (including level walking, running, lifting a 25 lb (roughly 11 kg) weight and lunging), our controller significantly reduced user energetics (metabolic cost or lower-limb biological joint work depending on the task) relative to the zero torque condition, ranging from 5.3 to 19.7%, without any manual controller modifications among activities. Thus, this task-agnostic controller can enable exoskeletons to aid users across a broad spectrum of human activities, a necessity for real-world viability., Competing Interests: Competing interests D.D.M. and A.J.Y. are inventors on a patent filed with the US Patent Office (US 18/340,981) by the Georgia Institute of Technology that covers some of the methods for state estimation described in this work. X, The Moonshot Factory, funded this work, contributed to its conceptualization and methodological design, and contributed much of the exoskeleton hardware and software used in this study., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Objective: To determine the optimal threshold, based on cadence and lifestyle counts per minute, to detect outdoor walking in mobility-limited older adults. Methods: Older adults (N = 25, median age: 77.0 years, interquartile range: 10.5) wore activity monitors during 80 outdoor walks. Walking bouts were identified manually (reference standard) and compared with identification using cadence thresholds (≥30, ≥35, ≥40, ≥45, and ≥50 steps/min) and >760 counts per minute using low frequency extension analysis. Results: Median walking bout duration was 10.5 min (interquartile range 4.8) and median outdoor walking speed was 0.70 m/s (interquartile range 0.20). Cadence thresholds of ≥30, ≥35, and ≥40 steps/min demonstrated high sensitivity (1.0, 95% confidence intervals [0.95, 1.0]) to detect walking bouts; estimates for specificity and positive predictive value were highest for ≥40 steps/min. Conclusion:Acadence threshold of ≥40 steps/min is recommended for detecting sustained outdoor walking in this population. [ABSTRACT FROM AUTHOR]

Humans routinely modify their walking speed to adapt to functional goals and physical demands. However, damage to the central nervous system (CNS) often results in abnormal modulation of walking speed and increased risk of falls. There is considerable interest in treatment modalities that can provide safe and salient training opportunities, feedback about walking performance, and that may augment less reliable sensory feedback within the CNS after injury or disease. Fully immersive virtual reality technologies show benefits in boosting training-related gains in walking performance; however, they lack views of the real world that may limit functional carryover. Augmented reality and mixed reality head-mount displays (MR-HMD) provide partially immersive environments to extend the virtual reality benefits of interacting with virtual objects but within an unobstructed view of the real world. Despite this potential advantage, the feasibility of using MR-HMD visual feedback to promote goal-directed changes in overground walking speed remains unclear. Thus, we developed and evaluated a novel mixed reality application using the Microsoft HoloLens MR-HMD that provided real-time walking speed targets and augmented visual feedback during overground walking. We tested the application in a group of adults not living with disability and examined if they could use the targets and visual feedback to walk at 85%, 100%, and 115% of each individual's self-selected speed. We examined whether individuals were able to meet each target gait speed and explored differences in accuracy across repeated trials and at the different speeds. Additionally, given the importance of task-specificity to therapeutic interventions, we examined if walking speed adjustment strategies were consistent with those observed during usual overground walking, and if walking with the MR-HMD resulted in increased variability in gait parameters. Overall, participants matched their overground walking speed to the target speed of the MR-HMD visual feedback conditions (all p -values > 0.05). The percent inaccuracy was approximately 5% across all speed matching conditions and remained consistent across walking trials after the first overall walking trial. Walking with the MR-HMD did not result in more variability in walking speed, however, we observed more variability in stride length and time when walking with feedback from the MR-HMD compared to walking without feedback. The findings offer support for mixed reality-based visual feedback as a method to provoke goal-specific changes in overground walking behavior. Further studies are necessary to determine the clinical safety and efficacy of this MR-HMD technology to provide extrinsic sensory feedback in combination with traditional treatments in rehabilitation. [ABSTRACT FROM AUTHOR]

In this paper, we propose a device simulation method that quantitatively represents the film profile characteristics. We simulated device characteristics according to pile‐up size and quantitatively confirmed relationship between film profile and device performance. We checked the device characteristics by changing the ratio of the pile‐up area to the planar area in units of pixels and changing the pile‐up stacking thickness. As a result, when ratio of the flat area in active area is 80% or more and the thickness difference is less than 10%, we obtained device efficiency of 90% and more compared to the ideal device (perfectly flat device) for red, green and blue devices. We could also confirm the reliability of the simulation method through device fabrication. And we expect that this study can contribute to improving the characteristics of the panel and device of solution processed OLED. [ABSTRACT FROM AUTHOR]

Most biomechanical research has focused on level-ground walking giving less attention to other conditions. As a result, most lower limb prosthesis studies have focused on sagittal plane movements. In this paper, an ESR foot is presented, of which five different stiffnesses were optimized for as many weight categories of users. It is characterized by a spherical ankle joint, with which, combined with the elastic elements, the authors wanted to create a prosthesis that gives the desired stiffness in the sagittal plane but at the same time, gives flexibility in the other planes to allow the adaptation of the foot prosthesis to the ground conditions. The ESR foot was preliminarily tested by participants with transfemoral amputation. After a brief familiarization with the device, each participant was asked to wear markers and to walk on a sensorized treadmill to measure their kinematics and kinetics. Then, each participant was asked to leave feedback via an evaluation questionnaire. The measurements and feedback allowed us to evaluate the performance of the prosthesis quantitatively and qualitatively. Although there were no significant improvements on the symmetry of the gait, due also to very limited familiarization time, the participants perceived an improvement brought by the spherical ankle joint. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is a common neurodegenerative disease. PD misdiagnosis can occur in early stages. Gait impairment in PD is typical and is linked with an increased fall risk and poorer quality of life. Applying machine learning (ML) models to real-world gait has the potential to be more sensitive to classify PD compared to laboratory data. Real-world gait yields multiple walking bouts (WBs), and selecting the optimal method to aggregate the data (e.g., different WB durations) is essential as this may influence classification performance. The objective of this study was to investigate the impact of environment (laboratory vs. real world) and data aggregation on ML performance for optimizing sensitivity of PD classification. Gait assessment was performed on 47 people with PD (age: 68 ± 9 years) and 52 controls [Healthy controls (HCs), age: 70 ± 7 years]. In the laboratory, participants walked at their normal pace for 2 min, while in the real world, participants were assessed over 7 days. In both environments, 14 gait characteristics were evaluated from one tri-axial accelerometer attached to the lower back. The ability of individual gait characteristics to differentiate PD from HC was evaluated using the Area Under the Curve (AUC). ML models (i.e., support vector machine, random forest, and ensemble models) applied to real-world gait showed better classification performance compared to laboratory data. Real-world gait characteristics aggregated over longer WBs (WB 30–60 s, WB > 60 s, WB > 120 s) resulted in superior discriminative performance (PD vs. HC) compared to laboratory gait characteristics (0.51 ≤ AUC ≤ 0.77). Real-world gait speed showed the highest AUC of 0.77. Overall, random forest trained on 14 gait characteristics aggregated over WBs > 60 s gave better performance (F1 score = 77.20 ± 5.51%) as compared to laboratory results (F1 Score = 68.75 ± 12.80%). Findings from this study suggest that the choice of environment and data aggregation are important to achieve maximum discrimination performance and have direct impact on ML performance for PD classification. This study highlights the importance of a harmonized approach to data analysis in order to drive future implementation and clinical use. Clinical Trial Registration: [09/H0906/82]. [ABSTRACT FROM AUTHOR]

Human locomotion involves continuously variable activities including walking, running, and stair climbing over a range of speeds and inclinations as well as sit-stand, walk-run, and walk-stairs transitions. Understanding the kinematics and kinetics of the lower limbs during continuously varying locomotion is fundamental to developing robotic prostheses and exoskeletons that assist in community ambulation. However, available datasets on human locomotion neglect transitions between activities and/or continuous variations in speed and inclination during these activities. This data paper reports a new dataset that includes the lower-limb kinematics and kinetics of ten able-bodied participants walking at multiple inclines (±0°; 5° and 10°) and speeds (0.8 m/s; 1 m/s; 1.2 m/s), running at multiple speeds (1.8 m/s; 2 m/s; 2.2 m/s and 2.4 m/s), walking and running with constant acceleration (±0.2; 0.5), and stair ascent/descent with multiple stair inclines (20°; 25°; 30° and 35°). This dataset also includes sit-stand transitions, walk-run transitions, and walk-stairs transitions. Data were recorded by a Vicon motion capture system and, for applicable tasks, a Bertec instrumented treadmill. Measurement(s) locomotory behavior • able-bodied gait • joint kinematics • joint kinetics Technology Type(s) motion capture • forceplates Sample Characteristic - Organism Homo sapiens Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.16611523 [ABSTRACT FROM AUTHOR]

Gait speed is a reliable outcome measure across multiple diagnoses, recognized as the 6th vital sign. The focus of the present study was on assessment of gait speed in long-term real-life settings with the aim to: (1) demonstrate feasibility in large cohort studies, using data recorded with a wrist-worn accelerometer device; (2) investigate whether the walking speed assessed in the real-world is consistent with expected trends, and associated with clinical scores such as frailty/handgrip strength. This cross-sectional study included n = 2809 participants (1508 women, 1301 men, [45–75] years old), monitored with a wrist-worn device for 13 consecutive days. Validated algorithms were used to detect the gait bouts and estimate speed. A set of metrics were derived from the statistical distribution of speed of gait bouts categorized by duration (short, medium, long). The estimated usual gait speed (1–1.6 m/s) appears consistent with normative values and expected trends with age, gender, BMI and physical activity levels. Speed metrics significantly improved detection of frailty: AUC increase from 0.763 (no speed metrics) to 0.798, 0.800 and 0.793 for the 95th percentile of individual's gait speed for bout durations < 30, 30–120 and > 120 s, respectively (all p < 0.001). Similarly, speed metrics also improved the prediction of handgrip strength: AUC increase from 0.669 (no speed metrics) to 0.696, 0.696 and 0.691 for the 95th percentile of individual's gait speed for bout durations < 30, 30–120 and > 120 s, respectively (all p < 0.001). Forward stepwise regression showed that the 95th percentile speed of gait bouts with medium duration (30–120 s) to be the best predictor for both conditions. The study provides evidence that real-world gait speed can be estimated using a wrist-worn wearable system, and can be used as reliable indicator of age-related functional decline. [ABSTRACT FROM AUTHOR]

Physical inactivity is the fourth leading cause of global mortality. Health organizations have requested a tool to objectively measure physical activity. Respirometry and doubly labeled water accurately estimate energy expenditure, but are infeasible for everyday use. Smartwatches are portable, but have significant errors. Existing wearable methods poorly estimate time-varying activity, which comprises 40% of daily steps. Here, we present a Wearable System that estimates metabolic energy expenditure in real-time during common steady-state and time-varying activities with substantially lower error than state-of-the-art methods. We perform experiments to select sensors, collect training data, and validate the Wearable System with new subjects and new conditions for walking, running, stair climbing, and biking. The Wearable System uses inertial measurement units worn on the shank and thigh as they distinguish lower-limb activity better than wrist or trunk kinematics and converge more quickly than physiological signals. When evaluated with a diverse group of new subjects, the Wearable System has a cumulative error of 13% across common activities, significantly less than 42% for a smartwatch and 44% for an activity-specific smartwatch. This approach enables accurate physical activity monitoring which could enable new energy balance systems for weight management or large-scale activity monitoring. Current methods to estimate energy expenditure are either infeasible for everyday use or associated with significant errors. Here the authors present a Wearable System using inertial measurement units worn on the shank and thigh that estimates metabolic energy expenditure in real-time during common steady-state and time-varying activities. [ABSTRACT FROM AUTHOR]

Foot progression angle (FPA) is vital in many disease assessment and rehabilitation applications, however previous magneto-IMU-based FPA estimation algorithms can be prone to magnetic distortion and inaccuracies after walking starts and turns. This paper presents a foot-worn IMU-based FPA estimation algorithm comprised of three key components: orientation estimation, acceleration transformation, and FPA estimation via peak foot deceleration. Twelve healthy subjects performed two walking experiments to evaluation IMU algorithm performance. The first experiment aimed to validate the proposed algorithm in continuous straight walking tasks across seven FPA gait patterns (large toe-in, medium toe-in, small toe-in, normal, small toe-out, medium toe-out, and large toe-out). The second experiment was performed to evaluate the proposed FPA algorithm for steps after walking starts and turns. Results showed that FPA estimations from the IMU-based algorithm closely followed marker-based system measurements with an overall mean absolute error of 3.1±1.3 deg, and the estimation results were valid for all steps immediately after walking starts and turns. This work could enable FPA assessment in environments where magnetic distortion is present due to ferrous metal structures and electrical equipment, or in real-life walking conditions when walking starts, stops, and turns commonly occur. [ABSTRACT FROM AUTHOR]

In this paper, we investigated film profile and device performance in pixel of 80ppi, 144ppi and 200ppi with 2nd harmonic structure which had thicker HIL and HTL. Pile‐up phenomena depended on ink formulation and pixel size and target film thickness. The excessive pile‐up was occurred in smaller pixel with same ink. Profiles were improved with changing the first layer ink that it had suppressed pile‐up in 200ppi size pixel. Device performance was also achieved in 200ppi size pixel compared with 80ppi size pixel device. [ABSTRACT FROM AUTHOR]

We propose to apply short‐range lurch control in‐plane switching (SLC‐IPS) as a fast response liquid crystal display (LCD) mode to virtual reality applications, where fast response times and high resolutions are essential. In this study, we discuss the SLC‐IPS electrode structure optimized for high‐resolution virtual reality applications. To maintain transmittance at high resolutions, we developed a one‐sided branch electrode structure with convex parts. The issue of slow response times can be resolved using the convex part of the electrode structure by analyzing the imaginary boundaries characterizing the SLC‐IPS. Thus, a response time of less than 2.2 ms can be obtained over all tones using a 1001‐ppi high‐resolution SLC‐IPS LCD. [ABSTRACT FROM AUTHOR]

Accurate and fast human motion pattern recognition is the key to ensuring lower limb assistive devices’ appropriate assistance. The research on human motion pattern recognition of lower limb assistive devices mainly focuses on sagittal gait. The motion pattern such as circular walking (CW) is asymmetric about the sagittal plane of the body. CW is common in daily living. However, the recognition algorithm of CW is rarely reported. Since lower limb assistive devices interact with humans, lacking the capability of recognizing CW is dangerous. Thus, to realize the accurate and fast recognition of CW, this article proposed a finite class Bayesian interference system (FC-BesIS). FC-BesIS is designed to recognize walking activities (linear walking and CW) and gait events (heel contact, load response, mid stance, terminal stance, pre-swing, initial swing, mid swing, and terminal swing). A finite class method which reduces the number of potential classes according to elimination rules before decision-making is introduced. Elimination rules are designed based on likelihood estimation and sensor information. The experiments show that walking activities and gait events can be accurately and fastly recognized by FC-BesIS. The experiments also show that the performance of FC-BesIS in mean recognition accuracy (MRA) and mean decision time (MDT) is improved compared with BesIS. The MRA of walking activities and gait events are 100% and 97.38%, respectively. The MDT of walking activities and gait events are 28.19 ms and 33.94 ms, respectively. Overall, FC-BesIS has been proved to be an accurate and fast recognition algorithm for human motion patterns using wearable sensors. [ABSTRACT FROM AUTHOR]

This study systematically reviewed and quantified evidence regarding the effectiveness of eccentric overload training (EOT) on change-of-direction speed (CODS) performance. A keyword search was performed in 30 April 2020 in eight electronic bibliographic databases: SPORTDiscus, PubMed, Web of Science, Academic Search Complete, Cochrane Library, Scopus, CINAHL and Google Scholar. A meta-analysis was conducted to estimate the pooled effect size of EOT interventions on CODS performance compared to the control group. Study heterogeneity was assessed by the I2 index. Publication bias was assessed by the Begg's and Egger's tests. Eleven studies, including nine randomized controlled trials, one randomized crossover trial, and one non-randomized controlled trial met the eligibility criteria and were included in the review. Time of overall change-of-direction task completion among the EOT group was 1.35 standard deviations (95% confidence interval [CI] = 0.18, 2.52) shorter than that in the control group. In conclusion, EOT was found effective in improving CODS performance compared to the control group. Future studies should adopt a randomized experimental design, recruit large and representative samples from professional team sports, and examine the effect of EOT on various measures of CODS performance among population subgroups. [ABSTRACT FROM AUTHOR]

Aim: This study aimed to examine safer turning methods by focusing on and comparing gait and turn methods in relation to stopping when executing a turn while walking with an intravenous (IV) pole. Methods: The study participants included 33 healthy men. A situation was recreated in which an IV drip was placed in the peripheral vein of the left forearm of the participants and the IV pole was maneuvered using the left hand. A series of six movements was executed, including turn left and right, stopping. Gait was measured (by observing turning motion, stride, walking speed and head tilt angle), and subjective assessments were performed. Results: Compared with walking normally, walking with an IV pole and executing turns resulted in a decrease in the walking speed, an increase in the time required for walking, a decrease in the stride and a forward tilting in the head angle. Turning left without stopping was mostly accompanied by a spin turn, and the probability of the pole legs coming into contact with participants' legs (15.2%) was higher than that in other assessed movements of walking with a pole. In the subjective assessment, turning left without stopping displayed a lower sense of security (p <.05) than turning left with stopping. Conclusions: When turning while using an IV pole, the pole itself poses a risk of falling. Therefore, momentary stopping and checking the safety of one's footing is a preventive measure against falling. [ABSTRACT FROM AUTHOR]

Introduction: Joint hypermobility syndrome (JHS) symptoms of widespread joint hypermobility and pain, muscle weakness and reduced muscle‐tendon stiffness suggest that there may be an impact on gait parameters. Identification of gait abnormalities may inform assessment and management. The objective in the present study was to use a cross‐sectional designed study to explore the impact of JHS on gait parameters. Methods: A JHS group of 29 participants (mean age 37.57 (S.D. 13.77) years) was compared to a healthy control group of 30 participants (mean 39.27 (S.D. 12.59) years). Spatiotemporal parameters, joint kinematics and joint kinetics were captured using the Qualisys motion capture system synchronized with a Kistler force platform. Results: Statistically significant reductions in walking speed, stride length and step length were found in the JHS group, while stance and double support durations were significantly increased (p < 0.01). During the swing phase, the JHS group showed significantly less knee flexion (p < 0.01). Reductions in hip extensor moment, and knee power generation and absorption were identified in the JHS group (p < 0.01). No other gait parameters were significantly altered. Conclusion: The JHS group walked more slowly with a kinematic 'stiffening' pattern. Hypermobility was not evident during gait. The observed stiffening pattern could be a strategy to avoid pain and improve balance. Impairments in moment and power generation could be related to several symptomatic and etiological factors in JHS. Clinicians should carefully consider gait in the assessment and management of people with JHS targeting the impairments identified by the current study. [ABSTRACT FROM AUTHOR]

Typical anticipatory postural adjustments (APAs) in forward gait or step initiation tasks to prepare for possible disturbances caused by prime voluntary movements and to accelerate the body forward have been previously reported. However, it is not clear how wide the variations in step directions are differentiated and controlled in non-forward step initiation tasks during the APA phase. The main goal of this study is to explain the directional control mechanisms by investigating the APA of step initiation tasks in forward, diagonal, lateral, and posterior directions. The center of pressure (COP) trajectories and related muscle (soleus, tibialis anterior, and gluteus medius of both lower limbs) activities during the APA of step initiation tasks in nine different directions were analyzed in six healthy young males. Posterior shifts of COP during APA decreased as the direction became more lateral (0° to 90°). For posterior step initiations, COP moved anteriorly from the initial position to accelerate the center of mass of the whole body (COM) backward. Lateral shifts of COP toward the stepping foot during APA decreased as the stepping direction became more lateral (from 0° to 45° and from 180° to 113°) while it plateaued to about zero in the direction from 45° to 113°. Both anteroposterior and lateral displacements of COP in APA were nonlinearly modulated to each direction, but they were linearly related to the anteroposterior and mediolateral component of the velocities of COM at the take-off of the stance foot. Thus, the scaling of APA, reflected in the anteroposterior and lateral displacements of COP and the temporal sequence of selected muscle activities, was based on the anteroposterior and mediolateral components of the take-off velocity of COM that ultimately controls the direction of steps. [ABSTRACT FROM AUTHOR]

Aging-related neuromuscular and neurocognitive decline induces unsmooth movements in daily functional mobility. Here, we used a robust analysis of linear and angular spectral arc length (SPARC) in the single and dual task instrumented timed up-and-go (iTUG) test to compare functional mobility smoothness in fallers and non-fallers aged 85 and older. 64 participants aged 85 and older took part in this case control study. The case group (fallers, n = 32) had experienced falls to the ground in the 6 months prior to the assessment. SPARC analyses were conducted in all phases of the single and dual task iTUGs. We also performed correlation mapping to test the relation of socio-demographic and clinical features on SPARC metrics. The magnitude of between-group differences was calculated using D-Cohen effect size (ES). SPARC was able to distinguish fallers during the single iTUG (ES ≈ 4.18). Turning while walking in the iTUG induced pronounced unsmooth movements in the fallers (SPARC ≈ −13; ES = 3.52) and was associated with the ability to maintain balance in the functional reach task. This information is of importance in the study of functional mobility in the oldest-old and to assess the efficacy of fall-prevention programs. [ABSTRACT FROM AUTHOR]

Torsion adapters in lower limb prostheses aim to increase comfort, mobility and health of users by allowing rotation in the transversal plane. A preliminary study with two transtibial amputees indicated correlations between torsional stiffness and foot alignment to increase comfort and stability of the user depending on the gait situation and velocity. This paper presents the design and proof-of-concept of an active, bio-inspired prosthetic shank adapter and a novel approach to create a user-specific human-machine interaction through adapting the device's properties. To provide adequate support, load data and subjective feedback of subjects are recorded and analyzed regarding defined gait situations. The results are merged to an user individual preference-setting matrix to select optimal parameters for each gait situation and velocity. A control strategy is implemented to render the specified desired torsional stiffness and transversal foot alignment values to achieve situation-dependent adaptation based on the input of designed gait detection algorithms. The proposed parallel elastic drive train mimics the functions of bones and muscles in the human shank. It is designed to provide the desired physical human-machine interaction properties along with optimized actuator energy consumption. Following test bench verification, trials with five participants with lower limb amputation at different levels are performed for basic validation. The results suggest improved movement support in turning maneuvers. Subjective user feedback confirmed a noticeable reduction of load at the stump and improved ease of turning. [ABSTRACT FROM AUTHOR]

As turns and walking speed modulation are crucial for functional mobility, development of a field-based tool to objectively evaluate non-steady-state gait is essential. This study aimed to quantify spatiotemporal gait using three Android smartphones during steady-state walking, turns, and gait speed modulation in laboratory and free-living environments. In total, 24 adults ambulated along a 10-m walkway in both environments under seven conditions: straight walking, 90° left or right turn, and modulating gait speed from usual-slow, usual-fast, slow-fast, and fast-slow. Two smartphones were attached to the body, with another phone placed in a shoulder bag. Gait velocity, step time, step length, cadence, and symmetry were computed from smartphone-based tri-axial accelerometers and validated with motion capture and video, in laboratory and free-living environments, respectively. Validity was assessed using Pearson's correlation and Bland–Altman analysis. Gait velocity results revealed moderate to very high validity across all walking conditions, smartphone models, smartphone locations, and environments. Correlations for gait velocity ranged between 0.87–0.91 and 0.79–0.83 for straight walking, 0.86–0.95 and 0.86–0.89 for turning, and 0.51–0.90 and 0.67–0.89 for speed modulation trials, in laboratory and free-living environments, respectively. Step time, step length, and cadence demonstrated high to very high correlations for straight walking and turns. However, symmetry results revealed high correlations only during straight walking in the laboratory. Conditions that included slow walking showed negligible to moderate validity with a high bias. In conclusion, smartphones can be employed as field-based devices to assess steady-state walking, turning, and speed modulation across environment, model, and placement when walking faster than 0.5 m/s. [ABSTRACT FROM AUTHOR]

Personalized exoskeleton assistance provides users with the largest improvements in walking speed 1 and energy economy 2-4 but requires lengthy tests under unnatural laboratory conditions. Here we show that exoskeleton optimization can be performed rapidly and under real-world conditions. We designed a portable ankle exoskeleton based on insights from tests with a versatile laboratory testbed. We developed a data-driven method for optimizing exoskeleton assistance outdoors using wearable sensors and found that it was equally effective as laboratory methods, but identified optimal parameters four times faster. We performed real-world optimization using data collected during many short bouts of walking at varying speeds. Assistance optimized during one hour of naturalistic walking in a public setting increased self-selected speed by 9 ± 4% and reduced the energy used to travel a given distance by 17 ± 5% compared with normal shoes. This assistance reduced metabolic energy consumption by 23 ± 8% when participants walked on a treadmill at a standard speed of 1.5 m s -1 . Human movements encode information that can be used to personalize assistive devices and enhance performance., (© 2022. The Author(s).)

The vertical alignment mode is widely applied in liquid crystal (LC) devices but exhibits a slow response time. To induce fast switching of LCs, bifunctional reactive monomers (RMs) were mixed with polyimide (PI). Two types of RMs were used: RMs with alkyl spacers and alkyl-free RMs. The mixture of RMs and PI was treated with ultraviolet light under an electric field to induce the pre-tilted LC alignment. The newly fabricated alignment layers exhibited low threshold voltages and fast response times compared to pure PI. Furthermore, the alkyl-free monomers induced a faster switching of the LCs than RMs with alkyl spacers. [ABSTRACT FROM AUTHOR]

Summary: A person's physical activity has important health implications, so it is important to be able to measure aspects of physical activity objectively. One approach to doing that is to use data from an accelerometer to classify physical activity according to activity type (e.g., lying down, sitting, standing, or walking) or intensity (e.g., sedentary, light, moderate, or vigorous). This can be formulated as a labeled classification problem, where the model relates a feature vector summarizing the accelerometer signal in a window of time to the activity type or intensity in that window. These data exhibit two key characteristics: (1) the activity classes in different time windows are not independent, and (2) the accelerometer features have moderately high dimension and follow complex distributions. Through a simulation study and applications to three datasets, we demonstrate that a model's classification performance is related to how it addresses these aspects of the data. Dynamic methods that account for temporal dependence achieve better performance than static methods that do not. Generative methods that explicitly model the distribution of the accelerometer signal features do not perform as well as methods that take a discriminative approach to establishing the relationship between the accelerometer signal and the activity class. Specifically, Conditional Random Fields consistently have better performance than commonly employed methods that ignore temporal dependence or attempt to model the accelerometer features. [ABSTRACT FROM AUTHOR]

Inkjet printing (IJP) is on the rise to become a competitive production technology for organic light emitting diodes (OLEDs). Recent progress in printing technology with drop volumes down to the pL regime as well as constant performance improvements from material point of view have opened the way towards IT displays. Here target resolutions are 250 ppi and beyond. For this purpose, small molecules are highly suitable due to their low impact on ink viscosity and excellent device performance. Their current performance status is reviewed based on bottom and top emission. For the latter, crucial factors for high performance like film uniformity and precise thickness control are discussed. [ABSTRACT FROM AUTHOR]

For office workers as much as much as 77% of time at work is spent in sedentary behaviour, increasing the risk of cardio vascular disease, cancer, weight gain, obesity and musculoskeletal pain. Given the amount of time spent at work, increasing opportunities for moderate to vigorous physical activity for office workers can not only reduce risk of disease but also actively contribute to better brain function and reduced anxiety at work. In this research we adopt an ecological approach to understanding opportunities for physical activity at work. Using 1373 Fitbit data points from two collocated office workers with identical job descriptions, we demonstrate that episodes of movement in the office are of very short or short duration. Results were less clear for sedentary behaviour because of the potential for spurious step counts and the fact that accelerometers cannot distinguish between sitting and standing. The paper shows the limitations and potential of data from Fitbit devices as a means of understanding the opportunities and constraints of the organisational and physical environment for physical activity at work for office workers. [ABSTRACT FROM AUTHOR]

A model based on a harmonic oscillator describing human walking and balance with the sinusoidal trajectory of the center of mass of a subject during gait is presented. This model allows overcoming the traditional drift due to the double integration of raw acceleration data. The protocol uses a single 3D accelerometer worn at the pelvis level. The system computes the spatiotemporal gait and balance parameters when the subject is walking with or without aids. An incremental methodological approach is proposed and followed in the implementation and accuracy assessment. Eleven healthy subjects have participated to the study performing 6 trials over a fixed linear walking path at a self-selected speed. For reference, the protocol has imposed the execution of 52 steps whose length has been fixed at 60 cm. Different processing methods have been implemented and tested. The model identifies steps, walking time, and stepping frequency with an excellent reliability (absolute percentage accuracy error < 5%). When the information about the expected step length is given to the model, the percentage error in the measure of walking distance and speed is 3.25%. Without this input, this error rises to 4.95%, while for the anthropometric method is 3.68%. [ABSTRACT FROM AUTHOR]

Abstract (1) Background: This study compared manually-counted treadmill walking steps from the hip-worn DigiwalkerSW200 and OmronHJ720ITC, and hip and wrist-worn ActiGraph GT3X+ and GT9X; determined brand-specific acceleration amplitude (g) and/or frequency (Hz) step-detection thresholds; and quantified key features of the acceleration signal during walking. (2) Methods: Twenty participants (Age: 26.7 ± 4.9 years) performed treadmill walking between 0.89-to-1.79 m/s (2–4 mph) while wearing a hip-worn DigiwalkerSW200, OmronHJ720ITC, GT3X+ and GT9X, and a wrist-worn GT3X+ and GT9X. A DigiwalkerSW200 and OmronHJ720ITC underwent shaker testing to determine device-specific frequency and amplitude step-detection thresholds. Simulated signal testing was used to determine thresholds for the ActiGraph step algorithm. Steps during human testing were compared using bias and confidence intervals. (3) Results: The OmronHJ720ITC was most accurate during treadmill walking. Hip and wrist-worn ActiGraph outputs were significantly different from the criterion. The DigiwalkerSW200 records steps for movements with a total acceleration of ≥1.21 g. The OmronHJ720ITC detects a step when movement has an acceleration ≥0.10 g with a dominant frequency of ≥1 Hz. The step-threshold for the ActiLife algorithm is variable based on signal frequency. Acceleration signals at the hip and wrist have distinctive patterns during treadmill walking. (4) Conclusions: Three common research-grade physical activity monitors employ different step-detection strategies, which causes variability in step output. [ABSTRACT FROM AUTHOR]

Turning while walking is a common daily activity. Individuals with unilateral impairment frequently perform turns asymmetrically. The purpose of the study was to investigate the effect of a discomfort-inducing textured insole on symmetry of turning. Nine healthy individuals performed turns to the right while walking with no insole, immediately after the insole was inserted in the right shoe, and after walking for six minutes with the insole. The duration of turning, displacements of pelvic markers, and perceived level of discomfort were evaluated. Utilizing the insole was associated with the increased level of perceived discomfort (p<0.05). Moreover, using the insole was linked to changes in the displacement of two pelvic markers and larger asymmetry index while turning immediately after the insole was inserted in the right shoe as compared to no insole condition (p<0.05). The duration of right turning increased immediately after the insole was inserted (p<0.05) and after walking with the insole for six minutes. The results indicate that the textured insole creates asymmetry of turning in healthy individuals. The outcome provides a background for future studies focused on using a textured insole to minimize the asymmetry of turning commonly seen in individuals with unilateral impairment. [ABSTRACT FROM AUTHOR]

A simple, low-power and wearable health analyzer for early identification and management of some diseases is presented. To achieve this goal, we propose a walking pattern analysis system that uses features, such as speed, energy, turn ratio, and bipedal behavior to characterize and classify individuals in distinct walking-ages. A database is constructed from 74 healthy young adults in the age range from 18 to 60 years using the combination of inertial signals from an accelerometer and a gyroscope on a level path including turns. An efficient advanced signal decomposition method called improved complete ensemble empirical mode decomposition with adaptive noise (improved CEEMDAN) was used for feature extraction. Analyzes show that the gait of healthy able-bodied individuals exhibits a natural bipedal asymmetry to a certain level depending on the activity-type and age, which relate to individual's functional attributes rather than pathological gait. The analysis of turn ratio, a measure of activity-transition energy change and stability, indicated turning to be less locally stable than straight-line walking making it a more reliable measure for determining falls and other health issues. Extracted features were used to analyze two distinct walking-age groups of the healthy young adults based on their walking pattern, classifying 18–45 years old individuals in one group and 46–60 years old in the other group. Our proposed simple, inexpensive walking analyzer system can be easily used as an ambulatory screening tool by clinicians to identify at risk population at the early onset of some diseases. [ABSTRACT FROM PUBLISHER]

Aims: To provide normative reference values for the 2-minute walk test (2MWT) for children and adolescents.Methods: A population-based sample of 2,631 boys and girls (3–17 years) contributed data to this 2011 study which was part of the NIH Toolbox for the Assessment of Neurological and Behavioral Function Norming Project. The 2MWT was performed over a 50 foot (15.2 meter) out-and-back course.Results: Overall, the mean (standard deviation) distance walked by the participants was 186.2 (33.9) meters. As a general linear model demonstrated that gender (F = 11.0,p=.001) and age (F = 127.6,p<.001) affected 2MWT distance, separate norms are provided for each gender and age stratum (e.g., 3-year-old boys,16-year-old girls). Based on these findings and correlational and regression analysis, separate explanatory equations for 2MWT distance for boys and girls are provided. The separate equations for boys and girls include age, age squared, height, and body mass as variables that explain around 40% of the variance in 2MWT distance.Conclusions: The study presents norms for the 2MWT performed by American boys and girls. The norms can be used to determine the presence of limitations in walking endurance in this population. [ABSTRACT FROM AUTHOR]

Background. Turning is ubiquitous in activities of daily living. For people with hemiplegia, persistent impairments in strength, balance, and coordination will affect their ability to turn safely. Consequently, turning retraining should be addressed in rehabilitation programs. To measure turning for these individuals, a reliable clinical tool is required. Objective. To investigate (i) the intrarater, interrater, and test-retest reliability of the timed 180° turn test; (ii) the correlation of the timed 180° turn test with other measures of stroke-specific impairments; and (iii) the cut-off time that best discriminates individuals with hemiplegia from chronic stroke and healthy older adults. Methods. 33 individuals with hemiplegia due to chronic stroke and 32 healthy elderly individuals participated in this cross-sectional study. The timed 180° turn test was administered along with other measures of stroke-specific impairment. Results. The timed 180° turn test demonstrated excellent intrarater, interrater, and test-retest reliability in individuals with hemiplegia from chronic stroke. The timed 180° turn test (times) significantly correlated with the Fugl-Meyer Assessment of the Lower Extremities (FMA-LE), affected ankle plantar flexion strength, the 5-Times-Sit-To-Stand test, the Berg Balance Scale (BBS), and the Timed Up and Go (TUG) test. Conclusion. The timed 180° turn test is a reliable clinical tool to assess the turning ability of subjects with hemiplegia from chronic stroke. [ABSTRACT FROM AUTHOR]

Humans and other cursorial mammals have distal leg muscles with high in-series compliance that aid locomotor economy. This muscle- tendon design is considered sub-optimal for injecting net positive mechanical work. However, humans change speed frequently when walking and any acceleration requires net positive ankle work. The present study unveiled how the muscle-tendon interaction of human ankle plantar flexors are adjusted and integrated with body mechanics to provide net positive work during accelerative walking. We found that for accelerative walking, a greater amount of active plantar flexor fascicle shortening early in the stance phase occurred and was transitioned through series elastic tissue stretch and recoil. Reorientation of the leg during early stance for acceleration allowed the ankle and whole soleus muscle-tendon complex to remain isometric while its fascicles actively shortened, stretching in-series elastic tissues for subsequent recoil and net positive joint work. This muscle-tendon behaviour is fundamentally different from constantspeed walking, where the ankle and soleus muscle-tendon complex undergo a period of negative work to store energy in series elastic tissues before subsequent recoil, minimizing net joint work. Muscles with high in-series compliance can therefore contribute to net positive work for accelerative walking and here we show a mechanism for how in human ankle muscles. [ABSTRACT FROM AUTHOR]

For people with lower limb amputation, a user-specific human-machine interaction with their prostheses is required to ensure safe and comfortable assistance. Especially during dynamic turning manoeuvres, users experience high loads at the stump, which decreases comfort and may lead to long-term tissue damage. Preliminary experiments with users wearing a configurable, passive torsional adaptor indicate increased comfort and safety achieved by adaptation of torsional stiffness and foot alignment. Moreover, the results show that the individual preference regarding both parameters depend on gait situation and individual preference. Hence, measured loads in the structure of the prosthesis and subjective feedback regarding comfort and safety during different turning motions are considered in a user-specific human-machine interaction strategy for a prosthetic shank adaptor. Therefore, the interrelations of gait parameters with optimal configuration are stored in an individual preference-setting matrix. Stiffness and foot alignment are actively adjusted to the optimal parameters by a parallel elastic actuator. Two subjects reported that they experienced appropriate variation of stiffness and foot alignment, a noticeable reduction of load at the stump and that they could turn with less effort. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop a methodology based on muscle synergies to investigate whether rectilinear and curvilinear walking shared the same neuro-motor organization, and how this organization was fine-tuned by the walking condition. Thirteen healthy subjects walked on rectilinear and curvilinear paths. Electromyographic data from thirteen back and lower-limb muscles were acquired, together with kinematic data using inertial sensors. Four macroscopically invariant muscle synergies, extracted through non-negative matrix factorization, proved a shared modular organization across conditions. The fine-tuning of muscle synergies was studied through non-negative matrix reconstruction, applied by fixing muscle weights or activation profiles to those of the rectilinear condition. The activation profiles tended to be recruited for a longer period and with a larger amplitude during curvilinear walking. The muscles of the posterior side of the lower limb were those mainly influenced by the fine-tuning, with the muscles inside the rotation path being more active than the outer muscles. This study shows that rectilinear and curvilinear walking share a unique motor command. However, a fine-tuning in muscle synergies is introduced during curvilinear conditions, adapting the kinematic strategy to the new biomechanical needs. [ABSTRACT FROM AUTHOR]

Background: Older adults have increased risks of balance issues and falls when walking and performing turns in daily situations. Changes of prioritization during different walking situations associated with dual tasking may contribute to these deficits. The objective of this study was therefore to investigate whether older adults demonstrate changes of prioritization during different walking paths. Methods: In total, 1,054 subjects with an age range from 50 to 83 years were selected from the first follow-up visit of the TREND (Tuebinger evaluation of Risk factors for Early detection of Neurodegenerative Disorders) study. They were classified according to their performance on the Trail Making Test (TMT) into good and poor TMT performers (based on recent results showing that cognitive flexibility affects prioritization strategies during straight walking). Absolute dual-task performance and relative dual-task costs (DTC, relative performance under dual-task conditions compared with single-task conditions) were assessed in two paradigms: walking while subtracting serial 7 s and walking while checking boxes on a clipboard. Both tasks were performed on straight and curved paths. Results: Overall, the poor TMT performers group performed worse in all single and dual tasks. Interestingly, the relative change in performance measured by dual-task costs differed in the groups between the two walking paths. On straight paths, poor TMT performers had a similar DTC of walking to that of good performers (p = 0.10) but had a significantly lower DTC of subtracting (p = 0.02). On curved paths, poor performers had a similar DTC of subtracting (p = 0.10), but their DTC of walking was significantly higher (p < 0.0001). Conclusion: Given that walking on curved paths is considered more difficult than that on straight paths and that the serial subtracting dual task is more difficult than the box checking dual task, this study in older adults provides evidence for the existence of a (walking) situation-dependent change of prioritization. If confirmed in other studies, situation-dependent change of prioritization should be included as a potential factor contributing to gait and balance impairments, and increased fall risk in older adults. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the temporal foot rollover data between straight-ahead and side-cut walking and to establish a reference dataset for obese and nonobese postmenopausal women. Pressure data were collected using the two-step protocol. The initial, final, and duration of contact of 10 foot areas were measured, as 5 instants and 4 phases. Significant temporal foot rollover differences were found during walking with and without directional changes; however, most of these differences were common for obese and nonobese subjects.The trailing limb during the side-cut task anticipated the initial and final contact of the lateral forefoot and increased midfoot and toes duration, suggesting a greater role of these areas in the initial break and in foot stability. The leading limb throughout the side-cut task exhibited longer duration of the heel, midfoot, and stance phase probably due to an increase in the stride length of the trailing limb and leaning of the trunk toward the inner side of the turn. Additionally, obese women revealed a later final contact and longer contact duration of some metatarsal areas suggesting that the greater inertia of these subjects demands more time to stabilize and prepare the foot for the next step. Please provide 3 to 5 keywords for the article. [ABSTRACT FROM AUTHOR]

Patients with total knee arthroplasty (TKA) demonstrate quadriceps weakness and functional limitations 1 year after surgery during daily tasks such as walking and stair climbing. Most biomechanical analyses of patients after TKA focus on quadriceps function and rarely investigate other lower-extremity muscles or high-demand ambulatory activities of daily living. The purpose of this investigation was to quantify lower-extremity muscle forces in patients with unilateral TKA during high-demand tasks of pivoting and descending stairs. Five patients with unilateral TKA and five age and sex-matched controls performed three bilateral high-demand tasks: (1) step down from an 8-inch platform, (2) inside pivot: 90° direction change toward planted limb, and (3) outside pivot: 90° direction change away from planted limb. Subject-specific musculoskeletal simulations were created in OpenSim to determine joint angles, moments, and lower-extremity muscle forces. The results indicate that patients with TKA adopt compensatory strategies at both the hip and knee. Patients with TKA demonstrated increased hip external rotation, decreased knee flexion, decreased quadriceps force, and decreased hip abductor force in all three tasks. These strategies are likely a result of quadriceps avoidance, which may stem from instability after TKA or a habitual strategy developed during the late stages of osteoarthritis. [ABSTRACT FROM AUTHOR]

Activity level and gait parameters during daily life are important indicators for clinicians because they can provide critical insights into modifications of mobility and function over time. Wearable activity monitoring has been gaining momentum in daily life health assessment. Consequently, this study seeks to validate an algorithm for the classification of daily life activities and to provide a detailed gait analysis in older adults. A system consisting of an inertial sensor combined with a pressure sensing insole has been developed. Using an algorithm that we previously validated during a semi structured protocol, activities in 10 healthy elderly participants were recorded and compared to a wearable reference system over a 4 h recording period at home. Detailed gait parameters were calculated from inertial sensors. Dynamics of physical behavior were characterized using barcodes that express the measure of behavioral complexity. Activity classification based on the algorithm led to a 93% accuracy in classifying basic activities of daily life, i.e., sitting, standing, and walking. Gait analysis emphasizes the importance of metrics such as foot clearance in daily life assessment. Results also underline that measures of physical behavior and gait performance are complementary, especially since gait parameters were not correlated to complexity. Participants gave positive feedback regarding the use of the instrumented shoes. These results extend previous observations in showing the concurrent validity of the instrumented shoes compared to a body-worn reference system for daily-life physical behavior monitoring in older adults. [ABSTRACT FROM AUTHOR]

The aim of the current study was to analyse the effect of 10-week eccentric overload training on kinetic parameters during change of direction (COD) in U-19 football players. The outcome measured included relative peak braking (rPB) and propulsive force (rPF), contact time (CT), time spent during braking (BT) and propulsive phase (PT), relative total (rTOT_IMP), braking (rB_IMP) and propulsive (rP_IMP) impulses. Between-group results showed a substantial better improvement (likely) in CT (ES: 0.72) and BT (ES: 0.74) during side-step cutting, and in rPB (ES: 0.84) and rB_IMP (ES: 0.72) during crossover cutting, in the experimental group (EXP) in comparison to control group (CON). Within-group analysis showed a substantially better performance (likely to almost certain) in CT (ES: 1.19), BT (ES: 1.24), PT (ES: 0.70), rPB (ES: 0.75), rPF (ES: 0.68), rTOT_IMP (ES: 0.48) and rB_IMP (ES: 0.50) in EXP during side-step cutting. Regarding crossover cutting, within-group analysis showed a substantial better performance (likely to almost certain) in CT (ES: 0.75), rPB (ES: 0.75), rPF (ES: 1.34), rTOT_IMP (ES: 0.61), rB_IMP (ES: 0.76) and rP_IMP (ES: 0.46) in EXP. In conclusion, the eccentric overload-based programme led to an improvement in kinetic parameters during COD football tasks. [ABSTRACT FROM PUBLISHER]

ABSTRACT Adults primarily walk to reach a new location, but why do infants walk? Do infants, like adults, walk to travel to a distant goal? We observed 30 13-month-old and 30 19-month-old infants during natural walking in a laboratory playroom. We characterized the bout structure of walking- when infants start and stop walking-to examine why infants start and stop walking. Locomotor activity was composed largely of brief spurts of walking. Half of 13-month-olds' bouts and 41% of 19-month-olds' bouts consisted of three or fewer steps-too few to carry infants to a distant goal. Most bouts ended in the middle of the floor, not at a recognizable goal. Survival analyses of the distribution of steps per bout indicated that the probability of continuing to walk was independent of the length of the ongoing bout; infants were just as likely to stop walking after five steps as after 50 steps and they showed no bias toward bouts long enough to carry them across the room to a goal. However, 13-month-olds showed an increased probability of stopping after 1-3 steps, and they did not initiate walking more frequently to compensate for their surfeit of short bouts. We propose that infants' natural walking is not intentionally directed at distant goals; rather, it is a stochastic process that serves exploratory functions. Relations between the bout structure of walking and other measures of walking suggest that locomotor exploration is constrained by walking skill in younger infants, but not in older infants. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 341-354, 2016. [ABSTRACT FROM AUTHOR]

Interactive treadmills were developed to improve the simulation of overground walking when compared to conventional treadmills. However, currently available interactive treadmills are expensive and inconvenient, which limits their use. We propose a low-cost and convenient version of the interactive treadmill that does not require expensive equipment and a complicated setup. As a substitute for high-cost sensors, such as motion capture systems, a low-cost motion sensor was used to recognize the subject's intention for speed changing. Moreover, the sensor enables the subject to make a convenient and safe stop using gesture recognition. For further cost reduction, the novel interactive treadmill was based on an inexpensive treadmill platform and a novel high-level speed control scheme was applied to maximize performance for simulating overground walking. Pilot tests with ten healthy subjects were conducted and results demonstrated that the proposed treadmill achieves similar performance to a typical, costly, interactive treadmill that contains a motion capture system and an instrumented treadmill, while providing a convenient and safe method for stopping. [ABSTRACT FROM AUTHOR]

Recent studies have reported a greater prevalence of spin turns, which are more unstable than step turns, in older adults compared to young adults in laboratory settings. Currently, turning strategies can only be identified through visual observation, either in-person or through video. This paper presents two unique methods and their combination to remotely monitor turning behavior using three uniaxial gyroscopes. Five young adults performed 90° turns at slow, normal, and fast walking speeds around a variety of obstacles while instrumented with three IMUs (attached on the trunk, left and right shank). Raw data from 360 trials were analyzed. Compared to visual classification, the two IMU methods' sensitivity/specificity to detecting spin turns were 76.1%/76.7% and 76.1%/84.4%, respectively. When the two methods were combined, the IMU had an overall 86.8% sensitivity and 92.2% specificity, with 89.4%/100% sensitivity/specificity at slow speeds. This combined method can be implemented into wireless fall prevention systems and used to identify increased use of spin turns. This method allows for longitudinal monitoring of turning strategies and allows researchers to test for potential associations between the frequency of spin turns and clinically relevant outcomes (e.g., falls) in non-laboratory settings. [ABSTRACT FROM AUTHOR]

Team field and court sports often demand the athlete to decelerate, change their direction, and accelerate again in response to a stimulus. All of this occurs in fractions of a second and needs to be completed in a shorter period of time than the athlete's opponent to be successful. The physical component of this quality is termed change of direction speed (CODS). In regard to training and improving CODS, there is currently disagreement on the efficacy of implementing traditional strength training methods as these primarily work through a vertical plane. Reviewing and discussing CODS and the necessary physical capacities that will lead to enhancement of this quality will help in making informed decisions for effective training methodologies. Therefore the primary purpose of this brief review was to identify and discuss the possible factors that influence CODS. The majority of the discussion focussed on the role of maximal relative strength in CODS performance and further discussion was conducted on testing methodologies. A search of the literature was completed to locate and examine any available articles that explored the relationship between strength and CODS. Principally, correlational and training studies were examined closely while studies investigating the kinematics of CODS movements were also evaluated. After the literature had been reviewed and discussed it was concluded that an athlete's relative maximal strength plays a significant role in determining CODS performance. Therefore when preparing team sport athletes for competition, strength training and weightlifting programs designed to improve maximal relative strength should be implemented to improve CODS. [ABSTRACT FROM AUTHOR]

Turning, while walking, is an important component of adaptive locomotion. Current hypotheses regarding the motor control of body segment coordination during turning suggest heavy influence of visual information. The authors aimed to examine whether visual field impairment (central loss or peripheral loss) affects body segment coordination during walking turns in healthy young adults. No significant differences in the onset time of segments or intersegment coordination were observed because of visual field occlusion. These results suggest that healthy young adults can use visual information obtained from central and peripheral visual fields interchangeably, pointing to flexibility of visuomotor control in healthy young adults. Further study in populations with chronic visual impairment and those with turning difficulties are warranted. [ABSTRACT FROM PUBLISHER]