Even though walking can be sustained for great distances, considerable energy is required plantarflexion around the instant of opposite leg heel contact. Different groups attempted to reduce metabolic cost with exoskeletons but none could achieve a reduction beyond level without exoskeleton, possibly because there no consensus on optimal actuation timing. The main research question our study was whether it possible obtain higher in by tuning timing.We measured means respiratory gas analysis....

Walking and running have fundamentally different biomechanics, which makes developing devices that assist both gaits challenging. We show a portable exosuit assists hip extension can reduce the metabolic rate of treadmill walking at 1.5 meters per second by 9.3% 2.5 4.0% compared with locomotion without exosuit. These reduction magnitudes are comparable to effects taking off 7.4 5.7 kilograms during running, respectively, in range has shown meaningful athletic performance changes. The...

Evaluation of a soft exosuit designed to reduce metabolic requirements during walking.

Recent advances in wearable robotic devices have demonstrated the ability to reduce metabolic cost of walking by assisting ankle joint. To achieve greater gains future it will be important determine optimal actuation parameters and explore effect other joints. The aim present work is investigate how timing hip extension assistance affects positive mechanical power delivered an exosuit its on biological joint during loaded walking. In this study, we evaluated 4 different assistive profiles...

Powered ankle-foot exoskeletons can reduce the metabolic cost of human walking to below normal levels, but optimal assistance properties remain unclear. The purpose this study was test effects different timing and power characteristics in an experiment with a tethered exoskeleton. Ten healthy female subjects walked on treadmill bilateral 10 conditions. Artificial pneumatic muscles assisted plantarflexion during ankle push-off using one four actuation onset timings (36, 42, 48 54% stride)...

The increasing capabilities of exoskeletons and powered prosthetics for walking assistance have paved the way more sophisticated individualized control strategies. In response to this opportunity, recent work on human-in-the-loop optimization has considered problem automatically tuning parameters based realtime physiological measurements. However, common use metabolic cost as a performance metric creates significant experimental challenges due its long measurement times low signal-to-noise...

Robotic ankle-foot prostheses that provide net positive push-off work can reduce the metabolic rate of walking for individuals with amputation, but benefits might be sensitive to timing. Simple models suggest preemptive reduces center-of-mass work, possibly reducing rate. Studies bilateral exoskeletons have found beginning before leading leg contact minimizes rate, timing was not varied independently from and effects on biomechanics were measured. Most lower-limb amputations are unilateral,...

Purpose This study assessed initial foot contact patterns (IFCP) in a large group of distance runners and the effect speed on IFCP. Methods We determined strike index to classify IFCP groups, at four speeds (3.2, 4.1, 5.1, 6.2 m·s−1), by measuring center pressure (COP) with 2-m plantar plate. Such system allows direct localization COP footprint has low threshold value (2.7 N·cm−2), resulting more accurate data ground reaction forces than when obtained from force Results The distribution...

The soft exosuit is a new approach for applying assistive forces over the wearer's body through load paths configured by textile architecture. In this paper, we present body-worn lower-extremity and control that can independently level of assistance provided during negative- positive-power periods at ankle. was designed to create assisting ankle plantarflexion hip flexion, actuation system transmits from motors suit via Bowden cables. A cell two gyro sensors per leg are used measure...

The bi-articular m. gastrocnemius and the mono-articular soleus have different complementary functions during walking. Several groups are starting to use these biological as inspiration design prostheses with actuation components replace function of gastrocnemius. Simulation studies indicate that a configuration spring mimic could be beneficial for orthoses or exoskeletons. Our aim was test effect mimics compare this no-spring configuration. We tested 9 participants walking knee-ankle-foot...

Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some obtained this result by means high positive work assistance while others combined negative assistance. There no consensus about isolated contribution Therefore, aim present study examine effect varying at joint maintaining a fixed level with multi-articular soft exosuit. We tested eight participants during 1.5 ms−1 23-kg backpack....

This study assessed kinematic differences between different foot strike patterns and their relationship with peak vertical instantaneous loading rate (VILR) of the ground reaction force (GRF). Fifty-two runners ran at 3.2 m · s−1 while we recorded GRF lower limb kinematics determined pattern: Typical or Atypical rearfoot (RFS), midfoot (MFS) forefoot (FFS). RFS had longer contact times a leg stiffness than MFS. showed dorsiflexed ankle (7.2 ± 3.5°) positive angle (20.4 4.8°) initial MFS...

Previous ankle exoskeleton assistance techniques that were able to demonstrate metabolic reductions can be categorized into those delivered moment profiles similar the biological throughout stance phase, and others positive power only during push off. Both a powered-off condition compared in treadmill walking (1.5 m s-1) with soft exosuit. We hypothesized both result reduction when providing level of average exosuit at each (0.12 W kg-1) hip (0.02 while underlying global center-of-mass local...

This study focused on designing and evaluating a bilateral semi-rigid hip exoskeleton. The exoskeleton assisted the joint, capitalizing its proximity to body’s center of mass. Unlike rigid counterparts, design permitted greater freedom movement. A temporal force-tracking controller allowed us prescribe torque profiles during walking. We ensured high accuracy by tuning control parameters series elasticity. evaluation involved experiments with ten participants across force profile conditions...

Exoskeletons can influence human gait. A healthy gait is characterized by a certain amount of variability compared to non-healthy that has more inherent variability; however which exoskeleton assistance parameters are necessary avoid increasing or potentially lower below unassisted walking unknown. This study investigated the interaction effects timing and power on variability. Ten participants walked treadmill with bilateral ankle-foot exoskeletons under ten conditions different (varied...

Shoes or insoles embedded with carbon fiber materials to increase longitudinal stiffness have been shown enhance running and walking performance in elite runners, younger adults, respectively. It is unclear, however, if such modifications can translate enhanced mobility older adults who typically walk greater metabolic cost of transport compared adults. Here, we sought test whether adding footwear via could improve outcomes (eg, distance traveled transport) during the 6-minute test. 20 (10...

(1) Background: Peripheral artery disease (PAD) and related conditions significantly impair walking ability. Previous studies demonstrated that passive lightweight exosuits can improve biomechanics. However, most of these devices focus on assisting hip flexion. The aim this study was to investigate the effects flexion extension assistance joint kinetics muscle activation. We hypothesized there would be an optimal combination for measured parameters. (2) Methods: Four patients with PAD six...

Many gait impairments are characterized by asymmetry and result in reduced mobility. Exoskeletons could be useful for restoring symmetry assisting only one leg. However, we still have limited understanding of the effects unilateral exoskeleton assistance. Our aim was to compare bilateral assistance using a within-subject study design.Eleven participants walked different conditions. In Unilateral conditions, leg assisted. Bilateral Matched Total Work, half from conditions applied both legs...

Purpose. We aimed to determine the effect of speed-induced changes in foot contact patterns on vertical instantaneous loading rate (VILR). hypothesized that transition runners, i.e. runners shift towards a mid- (MF) or forefoot pattern (FF) when running speed increases, show smaller increases VILR than non-transition remain with rearfoot (RF). Methods. Fifty-two male and female ran overground at 3.2, 4.1, 5.1 6.2 m s-1. Ground reaction forces, lower limb sagittal plane knee ankle kinematics...