In persons post-stroke, diminished ankle joint function can contribute to inadequate gait propulsion. To target paretic impairments, we developed a neuromechanics-based powered exoskeleton. Specifically, this exoskeleton supplies plantarflexion assistance that is proportional the user’s soleus electromyography (EMG) amplitude only during phase of when stance limb subjected an anteriorly directed ground reaction force (GRF). The purpose feasibility study was examine short-term effects on...

ABSTRACT Measuring biomechanical work performed by humans and other animals is critical for understanding muscle–tendon function, joint-specific contributions energy-saving mechanisms during locomotion. Inverse dynamics often employed to estimate joint-level contributions, deformable body estimates can be used study the foot. We recently discovered that these commonly experimental fail explain whole-body energy changes observed human walking. By re-analyzing previously published data, we...

Lower-limb wearable robotic devices can improve clinical gait and reduce energetic demand in healthy populations. To help enable real-world use, we sought to examine how assistance should be applied variable conditions suggest an approach derived from knowledge of human locomotion mechanics establish a 'roadmap' for robot design. We characterized the changes joint during walking running across range incline/decline grades then provide analysis that informs development lower-limb exoskeletons...

Abstract Prosthetic feet are designed to store energy during early stance and then release a portion of that late stance. The usefulness providing more return depends on whether or not transfers up the lower limb aid in whole body propulsion. This research examined how increasing prosthetic foot affected walking mechanics across various slopes. Five people with uni-lateral transtibial amputation walked an instrumented treadmill at 1.1 m/s for three conditions (level ground, +7.5°, −7.5°)...

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...

With the recent technological advancements of prosthetic lower limbs, there is currently a great desire to objectively evaluate existing prostheses. Using novel biomechanical analysis, purpose this case study was compare mechanical energy profiles anatomical and two disparate prostheses: passive prosthesis an active prosthesis.An individual with transtibial amputation who customarily wears (Elation, Össur) (BiOM, iWalk, Inc.) 11 healthy subjects participated in instrumented gait analysis....

There are many studies that have investigated biomechanical differences among prosthetic feet, but not changes due to adaptation over time. is a need for objective measures quantify the process of individuals with transtibial amputation. Mechanical power and work profiles primary focus modern energy-storage-and-return type prostheses, which strive increase energy return from prosthesis. The amount prosthesis stores returns (i.e., negative positive work) during stance directly influenced by...

We herein discuss the use of a ferrimagnetic nanowire for current-induced domain wall motion in order to satisfy both high perpendicular anisotropy and low saturation magnetization. demonstrate magnetic nanowires with various magnetizations by using micromagnetic analytical calculations. The intrinsic critical current velocity was reduced decrease magnetization even if width almost constant, also can be optimum wire width. A significant reduction density obtained decreasing spin polarization...

Abstract Background The human ankle joint has an influential role in the regulation of mechanics and energetics gait. can modulate its ‘quasi-stiffness’ (ratio plantarflexion moment to dorsiflexion displacement) response various locomotor tasks (e.g., load carriage). However, direct effect stiffness on metabolic energy cost during is not fully understood. purpose this study was determine how net affected by while walking under different force demands (i.e., with without additional load)....

In this paper, we investigate the effects of easy axis direction against magnetoimpedance elements on stepped impedance properties. The angle between and element width is changed from 0° to 90°, examine resulting profiles. magnetic field at which highest shifts a lower with increasing angles, can be explained by bias susceptibility theory. On other hand, changes appear for an in range 35°–75°. We confirmed property through our observations that those jumps occur transitional points domain...

Uneven ground is a frequently encountered, yet little-studied challenge for individuals with amputation. The absence of control at the prosthetic ankle to facilitate correction surface inconsistencies, and diminished sensory input from extremity, add unpredictability an already complex problem, leave limited means produce appropriate corrective responses in timely manner. Whole body angular momentum, L, its variability across several strides may provide insight into extent which individual...

In Brief Ankle-foot orthoses (AFOs) can act like rotational springs to enhance gait function in individuals with motor impairments. The performance of an AFO during use is primarily a its mechanical stiffness properties. Hence, objective analysis crucial for future prescription and understanding the contributions kinetics performance. Valid estimates be obtained if loads applied testing replicate loading conditions gait. However, sensitivity changes (location directions all forces) unknown....

An objective understanding of human foot and ankle function can drive innovations bio-inspired wearable devices. Specifically, knowledge regarding how mechanical force work are produced within the foot-ankle structures help determine what type materials or components required to engineer In this study, we characterized combined functions during walking by synthesizing total force, displacement, profiles from distal shank. Eleven healthy adults walked at four scaled speeds. We quantified...

We developed a 21-pole high-temperature superconductor thin-film microstrip filter with steep attenuation. This is applicable in the International Mobile Telecommunications-2000 (IMT-2000) base station receiver system, where high selectivity needed to avoid interference from signals personal handyphone system (PHS) band just below IMT-2000 band. The out-of-band rejection of this 1 MHz passband edge more than 40 dB. Owing improvements design and fabrication processes, we also eliminated need...

Abstract Lower-limb wearable robotic devices can provide effective assistance to both clinical and healthy populations; however, how should be applied in different gait conditions environments is still unclear. We suggest a biologically-inspired approach derived from knowledge of human locomotion mechanics energetics establish ‘roadmap’ for robot design. In this study, we characterize the changes joint during walking running across range incline/decline grades then an analysis that informs...

Older adults walk with less push-off power than younger adults. Principally attributed to plantar flexor dysfunction, growing evidence implicates interactions between the foot and ankle as critical for generating effective push-off. Our purposes were measure age effects on foot–ankle mechanical transmission (FAMT, ie, ratio metatarsal phalangeal extension medial gastrocnemius fascicle length change), its association during walking. We hypothesized that (1) FAMT would be lesser in older (2)...

Background: Despite evidence that passive prosthesis mechanical properties can directly affect user experience, prosthetists have access to minimal information regarding the interactions between a prosthetic foot and proximal modular componentry. Objectives: This study quantified stance phase behavior of transtibial system through addition componentry dynamic response (DR) foot. Study Design: Repeated measures, characterization. Methods: Maximum displacement energy return were measured with...

Stride-to-stride fluctuations of joint kinematics during walking reflect a highly structured organization that is characteristic healthy gait. The stride-to-stride disturbed in lower-limb prosthesis users, yet the factors contributing to this difference are unclear. One potential contributor changes altered push-off mechanics experienced by passive users. purpose our study was determine if affect transtibial amputees. Twenty-two unilateral amputees were enrolled 6-week cross-over study,...

The dependence of saturation magnetization and uniaxial anisotropy constant on current-induced domain wall motion in a magnetic nanowire with perpendicular was analyzed through micromagnetic simulation. results indicated that the critical current density linearly decreased by reducing magnetization. Even if width changed constant, did not influence since increase caused an effective anisotropy. It revealed decrease dominant factor density.

In this study, the effect of a pinning field on critical current density for current-induced domain wall motion in nanowires with perpendicular magnetic anisotropy was investigated using micromagnetic simulations. order to estimate notched nanowires, we conducted energy calculations various saturation magnetizations. The increased as notch size increased. decreased magnetization decreased. As result, causes reduction density. Therefore, significant can be obtained by decreasing...

This paper describes a ring shape Permalloy magnetoresistive detector for magnetic bubble domains. The advantages over rectangular are large increase in signal, low noise generated by rotating field, and no critical limitation of location. optimal design the was obtained from calculated distributions domain stray fields. Typical geometry is as follows: film thickness = 300 Å, width sensor 15 μm, inner diameter 100 μm. resistance 600 Ω. yielded 12 mV output signals 100μm when in-plane field...