Explore the vast range of titles available.

While design modifications present on work boots improve safety, they may not always provide optimal human performance during work tasks. Understanding the impact of these different design features on biomechanical and physiological postural control and locomotion variables can aid in better design modifications that can provide a safe and efficient human performance. This brief review focuses on a series of studies conducted by the current research team, that have tested three different work boots (SB: high-top steel-toed work boots; TB: high-top tactical work boots; SR: low-top slip-resistant work boots). The series of studies included testing of these work boots or combinations of them under acute and chronic simulated occupational workloads, assessing biomechanical variable such as postural stability, gait, slips, and muscle activity, as well as physiological variables such as heart rate, energy expenditure, oxygen consumption, and pain perception. The impact of each of the work boots and their design feature on postural control and locomotion are summarized from these studies’ previously published literature. Finally, work boot design suggestions for optimal human performance are provided for better work boot selection, modification, and design.

Background: Virtual reality (VR) is becoming a widespread tool in rehabilitation, especially for postural stability. However, the impact of using VR in a “moving wall paradigm” (visual perturbation), specifically without and with anticipation of the perturbation, is unknown. Methods: Nineteen healthy subjects performed three trials of static balance testing on a force plate under three different conditions: baseline (no perturbation), unexpected VR perturbation, and expected VR perturbation. The statistical analysis consisted of a 1 × 3 repeated-measures ANOVA to test for differences in the center of pressure (COP) displacement, 95% ellipsoid area, and COP sway velocity. Results: The expected perturbation rendered significantly lower (p < 0.05) COP displacements and 95% ellipsoid area compared to the unexpected condition. A significantly higher (p < 0.05) sway velocity was also observed in the expected condition compared to the unexpected condition. Conclusions: Postural stability was lowered during unexpected visual perturbations compared to both during baseline and during expected visual perturbations, suggesting that conflicting visual feedback induced postural instability due to compensatory postural responses. However, during expected visual perturbations, significantly lowered postural sway displacement and area were achieved by increasing the sway velocity, suggesting the occurrence of postural behavior due to anticipatory postural responses. Finally, the study also concluded that VR could be used to induce different postural responses by providing visual perturbations to the postural control system, which can subsequently be used as an effective and low-cost tool for postural stability training and rehabilitation.

Decrements to postural control manifest as an increase in muscle activity, indicating continuous attempts to maintain body equilibrium and postural stability. Extrinsic factors such as footwear, and intrinsic factors such as muscle fatigue, can affect postural stability. The purpose of this study was to analyze the impact of two types of military footwear and a military-type load-carrying task on lower extremity muscle activity during various postural stability tasks. Sixteen males’ (age: 26.63 ± 3.93 years; mass: 87 ± 12.4 kg; height: 178.04 ± 6.2 cm) muscle activity from knee flexors, extensors, ankle dorsiflexors, and plantar flexors were measured using electromyography in standard (STD) and minimalist (MIN) military footwear, before (PRE) and after (POST) a simulated workload during sensory organization and motor control tests on the Neurocom EquitestTM. Mean muscle activity was analyzed using 2 (footwear) × 2 (time) repeated measures ANOVA with an alpha level of 0.05. Results revealed a requirement of significantly greater muscle activity in POST and STD. MIN demonstrated lesser balance decrements POST workload, which could be attributed to its design characteristics. Results will help in suggesting footwear design characteristics to minimize muscular exertion while eliciting better postural control, and to prevent postural instability due to overexertion in military personnel.

Individuals with chronic ankle instability (CAI) demonstrate altered lower limb movement dynamics during jump landings, which can contribute to recurrent injury. However, the literature examining lower limb movement dynamics during a side-cutting task in individuals with CAI is limited. To assess lower limb joint kinetics and sagittal-plane joint stiffness during the stance phase of a side-cutting task in individuals with or without CAI. Cohort study. Motion-capture laboratory. Fifteen physically active, young adults with CAI (7 men, 8 women; age = 21.3 ± 1.6 years, height = 171.0 ± 11.2 cm, mass = 73.4 ± 15.2 kg) and 15 healthy matched controls (7 men, 8 women; age = 21.5 ± 1.5 years, height = 169.9 ± 10.6 cm, mass = 75.5 ± 13.0 kg). Lower limb 3-dimensional kinematic and ground reaction force data were recorded while participants completed 3 successful trials of a side-cutting task. Net internal joint moments, in addition to sagittal-plane ankle-, knee-, and hip-joint stiffness, were computed from 3-dimensional kinematic and ground reaction force data during the stance phase of the side-cutting task and analyzed. Data from each participant's stance phase were normalized to 100% from initial foot contact (0%) to toe-off (100%) to compute means, standard deviations, and Cohen d effect sizes for all dependent variables. The CAI group exhibited a reduced ankle-eversion moment (39%-81% of stance phase) and knee-abduction moment (52%-75% of stance phase) and a greater ankle plantar-flexion moment (3%-16% of stance phase) than the control group ( range = .009-.049). Sagittal-plane hip-joint stiffness was greater in the CAI than in the control group ( = 1.978, = .03). Our findings suggest that altered ankle-joint kinetics and increased hip-joint stiffness were associated when individuals with CAI performed a side-cutting task. These lower limb kinetic changes may contribute to an increased risk of recurrent lateral ankle sprains in people with CAI. Clinicians and practitioners can use these findings to develop rehabilitation programs for improving maladaptive movement mechanics in individuals with CAI.

Falls are extremely common in occupational settings. Intrinsic factors such as overexertion and extrinsic factors such as the supporting surface are causative factors of falls. The impact of prolonged exposure to a slippery surface on postural stability has not been previously studied. The purpose of the study was to analyze the effect of extended exposure to a dry and a slippery surface on postural stability. Eighteen males (age: 21.17 ± 3.38 years; height: 1.77 ± 0.08 m; mass: 89.81 ± 14.23 kg) were recruited and subjected to one-hour walking on a dry surface and a slippery surface on two different days. Participants’ balance was assessed using a force platform in stable and unstable conditions at 0, 30, and 60 min. Postural sway variables were analyzed using a 2 (surface) × 3 (time) repeated-measures ANOVA. Significant time main effects were observed in the stable condition with greater balance decrements at 30 and 60 min. Greater balance decrements were observed on the slippery surface compared to the dry surface in the unstable condition. The balance decrements can be attributed to overexertion due to the physiological workload of prolonged walking and to the potential gait modifications due to walking on the slippery surface.

Background: Postural stability and cognitive performance are challenged in firefighters. The purpose of this investigation was to examine the impact of 7-day ketone supplementation on postural stability, cognitive performance, and muscular activation before and after a physiological workload. Methods: Nine professional firefighters completed two experimental sessions (pre- and post-workload) in a counterbalanced, double-blind design. Participants ingested either a ketone salt (KS) or placebo (PLA) daily for seven days, and had an eighth ingestion 30 min prior to testing. Each experimental testing consisted of maximal voluntary contractions (MVIC) for four muscles (knee flexors—BF, extensor—VM, ankle dorsiflexors—TA, and plantar flexors—MG) using electromyography and postural stability testing (eyes open (EO), eyes closed (EC), and eyes open-dual-task using a FitLight™ system (EOT)), before (pre-workload) and after (post-workload) a simulated physiological workload. The workload consisted of 35 min steady state exercise at 60% of peak oxygen consumption wearing firefighter personal protective equipment (PPE). Results: Significant differences were limited to time effects (pre-workload vs. post-workload), with no differences between groups (KS vs. PLA). Significantly lower muscle activity in VM, TA, and MG during MVIC, greater postural sway and muscle activity in BF during EC and EOT, and slower response time during EOT were evident post-workload. Conclusions: A 7-day ketone supplementation does not impact postural stability, muscle activity, and cognitive tasks, but a fatiguing workload causes significant performance reduction.

The purpose of the study was to examine static postural control/balance in young adults with intellectual and developmental disabilities (IDD) and typically developing (TD) young adults before, during, and after an inclusive badminton intervention. Eight participants (four IDD-BADM and four TD-BADM) participated in a 12-week inclusive badminton intervention, with the other eight participants as matched controls (four IDD-CONTR and four TD-CONTR) (74.19 kg ± 9.8 kg, 171.96 cm ± 5.4 cm; 21.7 ± 1.8 years of age; nine females and seven males; eight with IDD and eight TD). The study followed a repeated measures design (pre, mid, post) before the intervention, at 6 weeks, and after 12 weeks. Static postural sway conditions included: bilateral stance eyes open (20 s), eyes closed (10 s), foam eyes open (20 s), foam eyes closed (10 s), and unilateral stance eyes open (10 s) and foam eyes open (10 s). Sway measurements included: average anterior/posterior (A/P) displacement (in), average medial/lateral (M/L) displacement (in), average 95% ellipsoid area (in2), and average velocity (ft/s). Significant time × group interactions were reported for average velocity (EO) (p = 0.030), average length (EO) (p = 0.030), 95% ellipsoid area (EO) (p = 0.049), and average A/P displacement (1LEO) (p = 0.036) for IDD-BADM. Significant time main effects were reported for average A/P displacement (FEO) (p = 0.040) for IDD groups. Significant time main effects were reported for average M/L displacement (EO) (p = 0.001), (EC) (p = 0.004), (FEO) (p = 0.005), (FEC) (p = 0.004), and average A/P displacement (EO) (p = 0.006) and (FEO) (p = 0.005) for TD groups. An inclusive badminton program indicated evidence of improved static postural control for those with IDD. However, no significant differences were reported for TD peers.

Accurate and unobtrusive measurement of upper-limb kinematics is critical for advancing wearable sensing technologies used in industrial ergonomics, human–machine interaction, and real-time biomechanics monitoring. This study evaluates the performance of two soft, flexible wearable sensors—BendLabs biaxial angular displacement sensors and StretchSense capacitive stretch sensors—for quantifying wrist and elbow motions during simulated dynamic industrial tasks. Wrist flexion–extension and radial–ulnar deviation were measured using BendLabs sensors mounted on the dorsal hand, while elbow flexion–extension was captured using StretchSense sensors positioned along the elbow joint. A multi-camera optical motion capture system served as the reference standard. Sensor data were preprocessed using baseline correction, smoothing, denoising, and normalized cross-correlation techniques to support temporal alignment with motion-capture recordings. Across all activities, the BendLabs sensors demonstrated moderate agreement with motion capture for wrist kinematics, with generally better performance for radial–ulnar deviation than for flexion–extension. StretchSense sensors demonstrated stronger agreement with motion capture for elbow flexion–extension, with performance that was generally consistent across task types. These findings support the feasibility of soft wearable sensors for capturing upper-limb kinematics during simulated occupational tasks and highlight their potential for integration into ergonomic assessment, occupational monitoring systems, and future industrial wearable platforms.

Background: Postural strategies such as ankle, hip, or combined ankle-hip strategies are used to maintain optimal postural stability, which can be influenced by the footwear type and physiological workload. Purpose: This paper reports previously unreported postural strategy scores during the six conditions of the sensory organization test (SOT). Methods: Fourteen healthy males (age: 23.6 ± 1.2 years; height: 181 ± 5.3 cm; mass: 89.2 ± 14.6 kg) were tested for postural strategy adopted during SOT in three types of occupational footwear (steel-toed work boot, tactical work boot, low-top work shoe) every 30 min during a 4-h simulated occupational workload. Postural strategy scores were analyzed using repeated measures analysis of variance at 0.05 alpha level. Results: Significant differences among postural strategy scores were only evident between SOT conditions, and but not between footwear type or the workload. Conclusions: Findings indicate that occupational footwear and occupational workload did not cause a significant change in reliance on postural strategies. The significant changes in postural strategy scores were due to the availability of accurate and/or conflicting sensory feedback during SOT conditions. In SOT conditions where all three types of sensory feedback was available, the ankle strategy was predominantly adopted, while more reliance on hip strategy occurred in conditions with absent or conflicting sensory feedback.

This study evaluated center-of-pressure (COP) and time-to-boundary (TTB) measures of postural control during a Lateral Step-Down Test in participants with chronic ankle instability (CAI). Cohort study. Biomechanics laboratory. Physically active adults with CAI (n = 15) and matched controls (n = 15). Traditional COP and TTB measures of postural control were computed in the medial/lateral (ML) and anterior/posterior (AP) directions. No significant results were found for the traditional COP measures (p > 0.05). The CAI group exhibited a lower TTB ML absolute minimum on their affected limb compared to the matched limb of the control group (p < 0.001). Additionally, on average the CAI group displayed significantly lower TTB ML mean of minima (p = 0.004) and TTB standard deviation of minima in the ML (p < 0.001) and AP directions (p = 0.002) regardless of limb. Sensorimotor impairments associated with CAI negatively alter spatiotemporal postural control and may cause a maladaptive reorganization of centrally mediated motor control strategies that results in bilateral postural control deficits during the Lateral Step-Down Test. In addition, traditional COP measures did not reveal any postural control deficits suggesting that a spatiotemporal analysis should be used when assessing postural control in participants with CAI. •Deficits in postural control are associated with CAI.•The Lateral Step-Down Test was completed on both limbs to assess postural control.•Center of pressure measures did not reveal any significant differences in postural control.•Spatiotemporal postural control deficts were found in individuals with CAI on both limbs.