Background: Robot-assisted gait training (RAGT) is an effective method for walking rehabilitation. Additionally, the body weight support (BWS) system reduces muscle fatigue while walking. However, no previous studies have investigated the effects of RAGT with BWS on isokinetic strength of quadriceps and hamstring muscles. Objects: The purpose of this study was to investigate the effects of torque, work, and power on the quadriceps and hamstring muscles during RAGT, using the BWS of three conditions in healthy subjects. The three different BWS conditions were BWS 50%, BWS 20%, and full weight bearing (FWB). Methods: Eleven healthy subjects (7 males and 4 females) participated in this study. The Walkbot_S was used to cause fatigue of the quadriceps and hamstring muscles and the Biodex Systems 4 Pro was used to measure the isokinetic torque, work, and power of them. After RAGT trials of each of the three conditions, the subjects performed isokinetic concentric knee flexion and extension, five at an angular velocity of 60°/s and fifteen at an angular velocity of 180°/s. One-way repeated analysis of variance was used to determine significant differences in all the variables. The least significant difference test was used for post-hoc analysis. Results: On both sides, there were significant differences in peak torque (PT) of knee extension and flexion between the three BWS conditions at an angular velocity of 60°/s and 180°/s conditions. A post-hoc comparison revealed that the PT in the BWS 50% was significantly greater than in the BWS 20% and the FWB and the PT in the BWS 20% was significantly greater than in the FWB. Conclusion: The results of this study suggest that the lower BWS during RAGT seems to lower the isokinetic torque, work, and power of the quadriceps and hamstring muscles because of the muscle fatigue increase.

본 연구에서는 20,000 톤급 해양플랜트 상부구조물(Topside)의 플로트오버 설치작업을 위해 개발된 수동형 갑판 지지 프레임 (Deck support frame)의 구조설계에 대해 다양한 실험계획법을 이용한 최소중량설계와 민감도 평가의 비교연구를 수행하였다. 수동형 갑판 지지 프레임의 주요 구조부재의 두께 치수 변수는 설계인자로 고려하였고, 응답치는 중량과 강도성능으로 선정하였다. 최소중량설계와 민감도 평가의 비교연구에 사용한 실험계획법은 직교배열설계법, Box-Behnken 설계법, 그리고 Latin hypercube 설계법이다. 실험계획법의 설계공간 탐색의 근사화 성능을 평가하기 위해 반응표면법을 각 실험계획법 별로 생성하여 근사화 정확도 특성을 검토하였다. 또한 최소 중량설계를 위해 최상 설계안의 결과로 부터 실험계획법의 특성에 따른 수치계산 비용, 중량감소 효과 등을 평가하였다. 수동형 갑판 지지 프레임의 구조설계에 대해 Box-Behnken 설계법이 가장 적합한 설계 결과를 나타내었다.

The purpose of this study effectiveness of core strengthening exercise programs on symmetric double limb support and balance ability for elderly. The subjects that 30 persons between the ages of 65~80 elderly participated were divided into two groups randomly for 8 weeks. Tetrax interactive balance system and Berg's balance scale were used to assess support and stability. Paired t-tests were used to evaluate the changes before and after intervention. The difference between the groups was compared using an independent t-test. The experimental group showed significantly increase weight support, stability, balance(p<.05). However, the control group not showed significantly increase weight support, stability, balance(p>.05). In a variation, experimental and control groups showed significantly increased rate of weight support, stability, balance(p<.05). Consequently, core strengthening exercise program should be considered as a therapeutic method for the elderly to improve the balance ability and effectiveness on falls.

이 연구의 목적은 뇌성마비 아동에게 앉은 자세에서 현수를 이용하여 체중지지를 해주었을 때 상지기능에 어떠한 영향을 미치는지 알아보는 것이다. 연구대상자는 뇌성마비 아동 5명과 뇌종양 아동 1명이었다. 연구대상자에게 harness를 착용하여 부분적 체중지지를 하기 전과 착용한 상태에서 손 뻗기 동작을 3차원 동작분석기를 이용하여 어깨관절과 손뻗기 동작에 걸린 시간을 측정하였고, Box and Block 검사를 실시하여 체중지지 전과 착용 시 상지 기능을

Body weight support treadmill training is a new and promising therapy in gait rehabilitation of patients with hemiplegia. The purpose of this study was to identify the effects of body weight support treadmill training on gait and standing balance in patients with hemiplegia. Eighteen patients with hemiplegia participated in the study. A 10 m-timed walk test, measurements of step length and standing balance score were administered. Intervention consisted of body weight support treadmill training five times a week for 2 weeks. The data were analyzed by paired t-test. Body weight support treadmill training scoring of standing balance, step length and 10 m-timed walk test showed a definite improvement. Body weight support treadmill training offers the advantages of task-oriented training with numerous repetitions of a supervised gait pattern. The outcomes suggest that patients with hemiplegia can improve their gait ability and standing balance through body weight support treadmill training.

While working in an industrial environment which requires extended periods of upright posture; workers tend to develop muscle fatigue due to the constant load on lower-limb muscles. In addition, when working while bending knees; muscle fatigue of lower back and hamstrings is increased due to the abnormal posture. This can lead to damage of muscles, induce musculoskeletal disorders, and reduce long-term working efficiency. Recent medical studies have shown that long-term working in an upright posture can induce musculoskeletal disorders such as foot fatigue, edema, pain and varicose veins. Likewise, medical and rehabilitation expenses have grown due to the increase in musculoskeletal conditions suffered by workers. For this problem, we aim to develop a device that can reduce the physical fatigue on the lower limbs by supporting the weight of workers during the extended periods of upright and bending postures in the industrial environments. In this paper, we have designed and manufactured a wearable weight support system; with a user intention algorithm that the users can maintain various postures. For validation of the developed system, we measured the muscle activity of the users wearing the system with EMG sensors.