Various back support exoskeletons (BSEs) have been developed to reduce the workload and risk of musculoskeletal disorders. However, evaluations such devices primarily focused on specific quantitative aspects like muscle activation level or metabolic cost without any assessment user perception comfort. In addition, absence an universal guidance agreement methods for quantifying efficacy has hampered a systematic comparison among devices. This study introduces newly passive BSE heavy load...

The control architecture underlying human reaching has been established, at least in broad outline. However, despite extensive research, the locomotion remains unclear. Some studies show evidence of high-level focused on lower-limb trajectories; others suggest that nonlinear oscillators such as lower-level rhythmic central pattern generators (CPGs) play a significant role. To resolve this ambiguity, we reasoned if oscillator contributes to locomotor control, walking should exhibit dynamic...

Minimum toe clearance (MTC) is an important indicator of the risk tripping. Aging and neuromuscular diseases often decrease MTC height increase its variability, leading to a higher Previous studies have developed visual feedback-based gait training systems modify MTC. However, these are bulky expensive, effects continue only for short time. We paid attention efficacy vibration in decreasing variability parameters, hypothesized that proper applied soles can reduce variability. Using shoes...

Fall-inducing systems have two critical applications. One is to obtain the biomechanical features of falling, and other systematically train individuals reduce risk falling. While former application necessitates occurrence falls, latter does not require fall-inducing perturbations be excessively intense. The purposes study were investigate effects perturbation intensities (a combination speeds durations) on number fall rates, maximum loading forces resulting from slips induced by a...

This study presents the development and preliminary validation of a novel system, called APEX (Adaptive Propulsion Enhancement eXperience), which aims to enhance gait propulsion in stroke survivors. The system utilizes dual-belt instrumented treadmill capable measuring ground reaction forces modulating belt speed real time provide visual biofeedback with dynamic promotion. We developed two promotion modes: propulsion-facilitating mode, extends contact elicit intrinsic propulsive effort...

Theoretical studies and robotic experiments have shown that asymptotically stable periodic walking may emerge from nonlinear limit-cycle oscillators in the neuro-mechanical periphery. We recently reported entrainment of human gait to mechanical perturbations with two essential features: 1) occurred only when perturbation period was close original (preferred) period, 2) always accompanied by phase locking so at end double-stance phase. In this study, we show a highly-simplified...

The movement patterns appropriate for exercise and manual labor do not always correspond to what people instinctively choose better comfort. Without expert guidance, can even increase the risk of injury by choosing a comfortable posture rather than one, notably when lifting objects. Even in situations where squatting is accepted as desirable strategy, tend more strategy stooping or semisquatting. common approach correcting posture, immobilizing vulnerable joints via fixation, insufficient...

Stride intervals of normal human walking exhibit long-range temporal correlations. Similar to the fractal-like behaviors observed in brain and heart activity, correlations have commonly been interpreted result from chaotic dynamics be a signature health. Several mathematical models reproduced this behavior by assuming dominant role neural central pattern generators (CPGs) and/or nonlinear biomechanics evoke chaos. In study, we show that simple model without CPG or capable chaos can reproduce...

Stroke often results in hemiplegia, which greatly affects the walking ability of patients. We propose a multi-functional portable ankle exoskeleton for use preventing foot-drops, assisting propulsion, and stabilizing inversion/eversion during to help gait rehabilitation stroke The was fabricated by 3D printing soft/rigid hybrid structure. device able prevent foot-drop assist propulsion with bi-directional cable-driven actuation system. It also showed capability motions using...

Quantitative characterization of ankle mechanical impedance is critical for understanding lower extremity function in persons with neurological disorders. In this paper, we examine the feasibility employing an robot and multivariable analysis to determine static 4 patients: 1 multiple sclerosis 3 stroke. We employed a scalar based vector field approximation method which was successful identifying young healthy subjects' impedance. It enabled clear interpretation spatial structure...

Entraining human gait with a periodic mechanical perturbation has been proposed as potentially effective strategy for rehabilitation, but the related studies have mostly depended on use of fixed-speed treadmill (FST) due to various practical constraints. However, imposing constant speed participants becomes critical problem because this constraint prohibits from adjusting speed, resulting in significant alterations natural biomechanics entrainment alters stride frequency. In study, we...

Abstract Fatigue can induce postural instability and even lead to falls. However, most current methods delay or reduce fatigue require long preparatory time, large expensive equipment. We propose a convenient method alleviate due fatigue. paid attention that aging share similar neurophysiological deterioration of sensory-motor function. Considering stochastic resonance via sub-sensory mechanical vibration increases stability in the elderly, we insole reduces negative effect on control....

Abstract Recent efforts on wearable robots have focused augmenting the motor performance and/or protecting wearer's body with lightweight structures. However, providing human‐scale force and structural stiffness usually conflicts wearability. Inspired by sandwich‐structured composites high strengths, widely employed in both nature man‐made structures, a mechanism of selectively stiffening garments (SSGs) utilizing anisotropic cellular cores rubber‐laminated face sheets is proposed. While...

Dynamically entraining human gait with periodic torque from a robot may provide an approach to walking therapy that is uniquely supportive of normal biological function. To test the feasibility this we perturbed unimpaired subjects by applying impulsive ankle at various frequencies. Eighteen out 19 exhibited entrained gaits: for small range frequencies their periods adapted synchronize mechanical perturbation. In addition, phase when synchronized was such perturbation assisted propulsion....

Entraining human gait with periodic torque from a robot may provide novel approach to robot-aided walking therapy that is competent exploit the natural oscillating dynamics of walking. To test feasibility this strategy we applied ankle neurologically impaired patients (one stroke and one multiple sclerosis). As observed in normal walking, both adapted their periods synchronize perturbation by phase-locking robotic at terminal stance phase. In addition, cadence became significantly faster due...

The MIT Cheetah demonstrated a stable 6 m/s trot gait in the sagittal plane utilizing self-stable characteristics of locomotion. This paper presents numerical analysis behavior quadruped robot model with proposed controller. We first demonstrate existence periodic gaits at various speeds and examine local orbital stability each trajectory using Poincar`e map analysis. Beyond stability, we additionally against large initial perturbations. Stability wide range speed enables gradual...

Mathematical techniques have provided tools to quantify the stability of rhythmic movements humans and machines as well mathematical models. One archetypal example is use Floquet multipliers: assuming periodic motion be a limit-cycle nonlinear oscillator, local has been assessed by evaluating rate convergence limit-cycle. However, accuracy assessment in experiments questionable: multipliers provide measure orbital for deterministic systems, but various components biological systems involve...

The practical operation of wearable robots requires intuitive, compact, yet reliable control interfaces. However, current myoelectric interfaces based on surface electromyography (EMG) often fail to achieve these requirements by demanding multiple sensors and exhibiting unreliable performance under limb posture changes. In this study, we show that a interface the musculotendinous junctions (MTJs) flexor digitorum superficialis (FDS) enables robotic glove with single EMG sensor identifying...

Recent advancements in functional near-infrared spectroscopy technology have offered a portable, wireless, wearable solution to measure the activity of prefrontal cortex (PFC) human neuroscience field. This study is first validate different contributions made by PFC's eight subregions healthy young adults reactive recovery responses following treadmill-induced unpredictable slip perturbations and vibrotactile cueing (i.e., precues).Our fall-inducing platform equipped with split-belt...

The purpose of this study is to explore the feasibility and therapeutic potential creative dance (CD) based exercise as a rehabilitation intervention for adolescents with cerebral palsy (CP). Participants were 10 spastic CP (mean age, 17.5±2.12 years; Gross Motor Function Classification System levels I [n=3] II [n=7]). Outcome measures included Measure-88 (GMFM-88; dimensions D E), spatiotemporal gait parameters, lower limb range motion during walking, body image, assessed using Body...

The maximal Lyapunov exponent (MLE) is a widely used indicator of the dependence on initial conditions various systems in many fields. However, both accuracy and consistency conventional method for estimating MLE heavily depend noise level. We developed with higher noise-robustness compared method. Considering that state space reconstruction using principal components can enhance when appropriate parameter values are used, we devised set algorithms finding proper window length number...

Previous studies have shown that absence or reduction of cutaneous sensory feedback can diminish human motor performance under maximum effort. However, it has not been explored whether any appropriate intervention in the input augment output performance, particularly tasks such as jumping involve kinematic chain entire body. Using shoes with active vibrating insoles, we applied mechanical vibration to soles 20 young and healthy adults evaluated change jump height muscle activation using...