Novice Users' Brain Activity and Biomechanics Change After Practicing Walking With an Ankle Exoskeleton.

Walking with an exoskeleton represents a sophisticated interplay between human physiology and mechanical augmentation, yet understanding of cortical responses in this context remains limited. To address this gap, this study aimed to explore cortical responses during walking with an ankle exoskeleton, examining how these responses evolve with familiarity to the augmentation. Healthy participants without prior exoskeleton experience underwent EEG, EMG, and motion capture analysis while walking with exoskeleton assistance at 1.

The effect of imperceptible Gaussian tendon vibration on the Hoffmann reflex.

Imperceptible vibratory Gaussian noise stimulation to the periphery is frequently being applied to humans to enhance motor performance. It is commonly theorized that this stimulation creates a Stochastic Resonance-like effect across both sensory and motor systems, but this idea has no empirical support. In contrast, there is substantial work showing that tendon vibration can be both excitatory and inhibitory on the lower motor neuron output.

Differences in muscle contraction onset as determined by ultrasound and electromyography.

Introduction: We characterize the agreement between the timing of muscle contraction onset detected by surface electromyography (sEMG), fine wire EMG (fwEMG), and motion-mode (M-mode) ultrasound for improved interpretations of clinical outcomes.

Methods: Eighteen healthy adults participated. Differences in contraction onset were compared between sEMG, fwEMG, and M-mode ultrasound collected during concentric contractions of the vastus lateralis and biceps brachii.

Spatiotemporal and kinematic changes in gait while carrying an energy harvesting assault pack system.

Soldiers are fielded with a variety of equipment including battery powered electronic devices. An energy harvesting assault pack (EHAP) was developed to provide a power source to recharge batteries and reduce the quantity and load of extra batteries carried into the field. Little is known about the biomechanical implications of carrying a suspended-load energy harvesting system compared to the military standard assault pack (AP).

Shooter-System Performance Variability as a Function of Recoil Dynamics.

Objective: The goal of this study was to quantify shooter performance relative to subtle variations in recoil energy.

Background: Marksmanship performance remains undefined for subtle distinctions in weapon recoil energy across common small-arms platforms.

Method: Weapons were customized using multiple components and ammunition types.

Iterative Assessment of Statistically-Oriented and Standard Algorithms for Determining Muscle Onset with Intramuscular Electromyography.

The onset of muscle activity, as measured by electromyography (EMG), is a commonly applied metric in biomechanics. Intramuscular EMG is often used to examine deep musculature and there are currently no studies examining the effectiveness of algorithms for intramuscular EMG onset. The present study examines standard surface EMG onset algorithms (linear envelope, Teager-Kaiser Energy Operator, and sample entropy) and novel algorithms (time series mean-variance analysis, sequential/batch processing with parametric and nonparametric methods, and Bayesian changepoint analysis).

Analysis of statistical and standard algorithms for detecting muscle onset with surface electromyography.

The timing of muscle activity is a commonly applied analytic method to understand how the nervous system controls movement. This study systematically evaluates six classes of standard and statistical algorithms to determine muscle onset in both experimental surface electromyography (EMG) and simulated EMG with a known onset time. Eighteen participants had EMG collected from the biceps brachii and vastus lateralis while performing a biceps curl or knee extension, respectively.

Computer-Based Algorithmic Determination of Muscle Movement Onset Using M-Mode Ultrasonography.

The study purpose was to evaluate the use of computer-automated algorithms as a replacement for subjective, visual determination of muscle contraction onset using M-mode ultrasonography. Biceps and quadriceps contraction images were analyzed visually and with three different classes of algorithms: pixel standard deviation (SD), high-pass filter and Teager Kaiser energy operator transformation. Algorithmic parameters and muscle onset threshold criteria were systematically varied within each class of algorithm.

Occupational health outcomes for workers in the agriculture, forestry and fishing sector: implications for immigrant workers in the southeastern US.

Background: Workers in the Agriculture, Forestry, and Fisheries (AgFF) sector experience exposures directly related to the work itself, as well as the physical environment in which the work occurs. Health outcomes vary from immediate to delayed, and from acute to chronic.

Methods: We reviewed existing literature on the health outcomes of work in the AgFF sector and identified areas where further research is needed to understand the impact of these exposures on immigrant Latino workers in the southeastern US.

Evaluation of gait and slip parameters for adults with intellectual disability.

Adults with intellectual disability (ID) experience more falls than their non-disabled peers. A gait analysis was conducted to quantify normal walking, and an additional slip trial was performed to measure slip response characteristics for adults with ID as well as a group of age- and gender-matched controls. Variables relating to gait pattern, slip propensity, and slip severity were assessed to compare the differences between groups.