An Integrated Dynamic Closed Loop Simulation Platform for Elbow Flexion Augmentation Using an Upper Limb Exosuit Model.

Wearable robotic devices are designed to assist, enhance or restore human muscle performance. Understanding how a wearable robotic device changes human biomechanics through complex interaction is important to guide its proper design, parametric optimization and functional success. The present work develops a human-machine-interaction simulation platform for closed loop dynamic analysis with feedback control and to study the effect of soft-robotic wearables on human physiology. The proposed simulation platform incorporates Computed Muscle Control (CMC) algorithm and is implemented using the MATLAB -OpenSim interface. The framework is generic and will allow incorporation of any advanced control strategy for the wearable devices. As a demonstration, a Gravity Compensation (GC) controller has been implemented on the wearable device and the resulting decrease in the joint moments, muscle activations and metabolic costs during a simple repetitive load lifting task with two different speeds is investigated.

Experimental and numerical investigation of a polypropylene orthotic device for assistance in level ground walking.

This study investigates the use of an orthotic device for improving pathologic gait lacking a heel-strike and its effect on the joint loads. The orthosis is fabricated from 10-mm thick polypropylene sheets joined together using a bolted joint. The gait trials are recorded using a Qualisys motion capture system and Kistler's force platform. The data recorded in this study comprise five male and five female participants, executing level ground gait under barefoot, shod and orthotic conditions. Computed tomography reconstructed foot bone-tissue model and computer-aided design model of the orthosis are used to predict the mechanical behaviour with and without orthosis under static loading. A one-way analysis of variance is conducted to compare the peak gait parameters in the early and late stance phase between the three walking conditions. The experimental results show that the orthosis reduces the peak joint forces and the rate of change of moment at the hip, knee and ankle joints. The finite element analysis results present a decrease in foot plantar pressure from 0.74 to 0.32 MPa with orthotic usage. The results of this study indicate that the orthosis can eliminate the heel-ground gap while retaining sufficient ankle motion and providing peak joint force reduction.

Effect of high heel gait on hip and knee-ankle-foot rollover characteristics while walking over inclined surfaces - A pilot study.

Given the massive number of individuals wearing high-heeled shoes, understanding the gait biomechanics associated with their use could provide insight into clinically preventable abnormalities. The effects of inclined surfaces on the high-heeled gait have been investigated in the present pilot study, as most walking surfaces encountered in routine life are rarely perfectly level grounded. The rollover shapes of the high-heel shod gait are calculated to obtain the desired results. An adjustable inclined walkway setup was fabricated and comprising fixed slots permitting discrete and variable angle of inclinations (≤30°). The gait trials were recorded for the heel shod walking of ten healthy female volunteers using the three-dimensional motion analysis system by varying the inclination of the fabricated walkway. From the calculated rollover shapes, the necessary radii of the hip and the knee-ankle- foot rollover shapes were obtained and a repeated measures analysis of variance was carried out to establish the existence of correlation between the angle of inclination and rollover radii. The results of the present pilot study show that for high heel-shod walking there exist variable radii of curvature for early and late stance phases and that the same may vary depending upon the inclination. The same information can be used to modify the design of high-heel shoes to improve the stability while retaining their aesthetics.