Publications by authors named "Seungtae Yang"

Wearable robots have been developed to assist the physical performance of humans. Specifically, exosuits have attracted attention due to their lightweight and soft nature, which facilitate user movement. Although several types of force controllers have been used in exosuits, it is challenging to control the assistive force due to the material's softness.

View Article and Find Full Text PDF

The use of wearable robots to provide walking assistance has rapidly grown over the past decade, with notable advances made in robot design and control methods toward reducing physical effort while performing an activity. The reduction in walking effort has mainly been achieved by assisting forward progression in the sagittal plane. Human gait, however, is a complex movement that combines motions in three planes, not only the sagittal but also the transverse and frontal planes.

View Article and Find Full Text PDF

High-collar shoes are a biomimetic approach to preventing lateral ankle injuries during high-demand activities; however, the influence of collar stiffness (CS) on parameters related to lateral ankle sprain prevention during running remains unclear. In this study, we investigated the effects of a custom-designed shoe CS on muscular activity, dynamic stability, and leg stiffness (K) during running using a biomimetic design approach inspired by the mechanisms of ankle sprain prevention. Sixteen healthy male participants ran on a treadmill while wearing a custom-designed high-collar shoe with low, medium, and high CS conditions, measured using circumferential ankle pressure (CAP).

View Article and Find Full Text PDF

Background: The shoe's collar plays a significant role in supporting the ankle during walking. Since the protective effect of the collar requires the circular embracing of the ankle and shank, a stiffer collar might be involved with increased circumferential ankle pressure (CAP). It is not clear how collar CAP affects walking performance.

View Article and Find Full Text PDF

[Purpose] The purpose of this study was to compare the differences in muscle strength and postural balance between fallers and non-fallers. We also compared the difference between normal and impaired balance groups using the same subjects and the same variables. [Subjects and Methods] Seventy-one healthy elderly females (age: 75.

View Article and Find Full Text PDF

[Purpose] Proper pedaling posture can improve muscle strength and cardiopulmonary function. To investigate proper pedaling posture for the elderly, this study compared the pedaling efficiency of the elderly with that of the young by using an index of effectiveness (IE) and kinematic results. [Subjects and Methods] Eight adults in their twenties and eight in their seventies participated in 3-min, 40 rpm cycle pedaling tests, with the same load and cadence.

View Article and Find Full Text PDF

[Purpose] This study aimed to determine appropriate measures for assessing balance ability according to difficulty level during standing tasks. [Subjects and Methods] The subjects were 56 old (>65 years) and 30 young (20-30 years) adults. By using the Berg balance scale, the subjects were divided into three groups: 29 healthy older (Berg score≥52), 27 impaired older (Berg score≥40), and 30 healthy young (Berg score≥55).

View Article and Find Full Text PDF

Background: As it is not easy to investigate various variables that affect exercise efficacies and cause injuries while pedaling in the actual experiment, especially for the elderly, the musculoskeletal model simulation with a comparison of measured electromyography (EMG) data could be used to minimize experimental trials.

Objective: The measured EMG data were compared with the muscle activities from the musculoskeletal model through forward (FD) and inverse dynamic (ID) analysis.

Methods: EMG was measured from eight young adult (20's) and eight elderly (70's) in three minutes pedaling with a constant load and 40 revolutions per minute (RPM) cadence.

View Article and Find Full Text PDF

[Purpose] In this study, a program was developed for leg-strengthening exercises and balance assessment using Microsoft Kinect. [Subjects and Methods] The program consists of three leg-strengthening exercises (knee flexion, hip flexion, and hip extension) and the one-leg standing test (OLST). The program recognizes the correct exercise posture by comparison with the range of motion of the hip and knee joints and provides a number of correct action examples to improve training.

View Article and Find Full Text PDF

[Purpose] The purpose of this study was to evaluate the changes in body stability of the elderly while walking on even surface ground under low light. [Subjects] Ten young males and ten elderly males participated in this experiment. [Methods] Each subject walked along a 7 m walkway five times at their preferred walking speed under normal (>300 lux, NORM) and low light conditions (<5 lux, LOW).

View Article and Find Full Text PDF

In this study, the accuracy of the inputs required for finite element analysis, which is mainly used for the biomechanical analysis of bones, was improved. To ensure a muscle force and joint contact force similar to the actual values, a musculoskeletal model that was based on the actual gait experiment was used. Gait data were obtained from a healthy male adult aged 29 who had no history of musculoskeletal disease and walked normally (171 cm height and 72 kg weight), and were used as inputs for the musculoskeletal model simulation to determine the muscle force and joint contact force.

View Article and Find Full Text PDF

A Fe-containing metal-organic framework, Fe-MOF-74, was solvothermally synthesized using FeCl2.4H2O and 2,5-di-hydroxy-1,4-benzenedicarboxylic acid. Characterization was conducted by XRD, BET surface area measurement, FT-IR spectroscopy, TGA, and elemental analysis, which confirmed successful preparation of Fe-MOF-74 having an identical framework structure to that reported for MOF-74.

View Article and Find Full Text PDF

A polyethylenimine-impregnated hierarchical silica monolith exhibited significantly higher CO(2) capturing capacity than other silica-supported amine sorbents, and produced a reversible and durable sorption performance.

View Article and Find Full Text PDF