Quick picking and heavy lifting are the most common problems in current workplaces. They can cause lumbar muscle damage. The operator then must spend energy, time, and money for recovery or rehabilitation. To solve this problem, we developed a passive-type assistive suit using air mesh material, elastic band, and wire. To determine the strength support effect of the passive-type assistive suit, electromyography (EMG) was performed for eight muscles and the maximum voluntary contraction (MVC) was analyzed when lifting weights of 0%, 15%, and 30% of the subject’s weight in a Semisquat motion. Results showed that MVC increased as the weight of the heavy object increased. However, its increase was not proportional to the decrease in MVC according to the presence or absence of assistive suits or the weight of the heavy object. The highest MVC was observed for the erector spinae muscle under all conditions. The greatest decrease in MVC according to working clothes was measured for the vastus lateralis muscle (lifting: 17.7±2.95%, lowering: 18.3±0.55%). These results show that lifting work performed while wearing a passive-type assistive suit using wires and elastic bands is effective in assisting muscle activity.

The purpose of the study was to evaluate the lumbar mobility and flexibility by the vertical vibration stimulation. The subjects were 21 young adults were divided into vibration group (n = 7) that applied 30 Hz vibration stimulation to the lumbar, foam roller group (n = 7) that relaxes the lumbar muscles with a foam roller, and good morning exercise group (n = 7) that stimulates the lumbar spine with the good morning exercise. The muscle strength, EMG and the sit & reach test were measured, to evaluate the lumbar mobility and flexibility before and after exercise intervention in each group. Results showed increasing in the vibrating group in muscle strength and EMG, and the good morning group and the vibrating group in the Sit & Reach test. This can be developed as a new alternative to exercise therapy for spine rehabilitation.

Many of the workers are exposed to work that burdens the musculoskeletal system, and musculoskeletal diseases, such as low back pain, are increasing every year. Various muscle support systems, such as wearable robots, have been developed to prevent musculoskeletal diseases at industrial sites, but the system is bulky. Therefore, the total weight is high, it is inconvenient to wear, and the wearer cannot freely perform the activities when power is not supplied. In this paper, in order to compensate for the shortcomings of the hard-type wearable robot system, a soft-type wearable suit using an elastic band was manufactured so that it is light and portable, as it does not require an actuator. The experiment was conducted to verify the effect of muscle strength assistance through an experiment (Measurement of Maximum Waist Torque and Measurement of the Approximate Dose) on the effect of the soft wearable suit. In addition, by making two different types of elastic bands in the wearable suit, it was possible to classify the more effective types for the waist and lower extremities according to the elasticity by comparing the muscle strength assisting effect according to the elastic band.

Farming is a typical task that includes repetitive tasks, incomplete working positions, and weight work, along with exposure to a number of musculoskeletal diseases and harmful factors. Therefore, in this study, work clothes were developed for older agricultural workers exposed to musculoskeletal diseases and alienated from the medical system. Work clothes can help in repetitive cropping and support the load on the work, preventing and mitigating farmers" diseases. To verify the effectiveness of the developed clothing, six men in their 20s were evaluated for muscle usage before and after wearing the clothing in two ways: stoop lifting and squat lifting. The results of this study showed that the mass of most muscles, except the gastrocnemius muscle, was reduced during lifting operations by stoop lifting after wearing work clothes. The reason why the gastrocnemius was more activated was that the ankle joint was greatly activated by dorsal flexion. For squatting and lifting, most of the muscle usage was reduced. In future research, we want to analyze the muscle characteristics of actual agricultural workers on wearing work clothes.

This study was undertaken to develop a bed-type cycling system of lower limbs for rehabilitation. This system consists of two modes of cycling: active and passive. Different velocity and loads are provided for improving the muscle function recovery and increasing the muscular strength. To analyze the muscle activity pattern, we measured muscular activity of lower limbs in the rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), medial gastrocnemius (MG), and soleus (SOL), while cycling in the supine position, and based on the pedaling direction. A total of 18 young and 23 elderly, healthy subjects participated in this study. Muscle activity of MG muscles was significantly different in the two age groups. This study could provide the reference data to develop cycling exercises for lower limbs during rehabilitation of the elderly patients.

The Interest in disease prevention and rehabilitation is increasing depending on increase of patients with spinal. This is being developed using the spine stabilization device is being studied. So far studies have only evaluated the effect on trunk stabilization exercises but analysis of human movement patterns for active movement and passive movement did not. We assessed the muscle activity of trunk and leg muscle during passive and active tilt mode on eight tilt directions at tilt angle of 30° using 3-D dynamic postural balance training system. We performed experimental study on the muscular activities of trunk muscle about rectus abdominis, external obliques, latissimus dorsi, erector spinae, and leg muscle about rectus femoris, Biceps femoris, Tibialis Anterior, gastrocnemius. As a result, muscle activation was different depending on the direction of movement and pattern. The results indicate that various patterns of spinal stabilization exercise system could be applied to an effective training of chronic low back pain patients.

The purpose of this study was to verify the validation of effect on improvement of muscle strength unbalance according to exercise load deviation during rowing exercise. We performed evaluation of muscular activity and joint torque before the test. We recruited twenty subjects who one side"s muscle strength is bigger in more 20% than other side. Subjects divided two groups. One is dominant left side and the other was dominant right side. Subjects performed rowing exercise in electric load deviation rowing equipment (Robo.gym, Humonic Co., Ltd., Daegu, Korea). Exercise performed four sets a day including 25 times a set, and three days a week. Measurements consist of evaluation of muscular activity and joint torque. Exercise load deviation adapted that different value of muscle strength in both arms multiplied 1RM% and added 1RM 50%. The results in adapted load deviation showed that the differences of maximal peak torque in 22.75% were getting increase significantly during exercise in 5.72%. This interpreted that rowing exercise with loading deviation types could provide muscle strength and muscular endurance exercise in same time for balance. Our study found out that loading deviation could provide muscle strength and muscular endurance exercise for improving muscle unbalance.

We investigated an early rehabilitation training system that increase the intensity of patient rehabilitation training to shorten the time it takes for patients to progress to a secondary rehabilitation training stage by allowing patients incapable of self-ambulation. It consisted of tilting bed, unstable platform using strong springs and training program for lower limb rehabilitation. We performed experimental study on the muscular activities of tibialis anterior(TA), soleus(SO), gastrocnemius(GA) in the lower extremities during training of straight line, circle, quardrangle pattern during tilting angle of 30°, 60°. The muscle activities were higher during tilting angle of 30° than 60°. In straight line pattern, the muscle activities were higher by SO, GA and TA during medio-lateral direction, however, by TA, SO and GA during anterio-posterior direction. In circle and quardrangle pattern, the muscle activities were higher by TA, SO and GA during clockwise and counterclockwise direction. The results indicate that the early rehabilitation training system could be applied to improve the lower extremity muscular strength for elderly and patients, especially, stroke.

In this paper, we estimated the effects of different color stimulation on the cognitive function of human quantitatively. For the stimulations we used color lights with 6 color filters such as red, yellow, green, blue, violet and white. The experiment was performed in a soundproof chamber. 50 young male and female subjects were participated in the experiment. To find the appropriate color cognitive function, the endogenous visuospatial attention task(EVAT) and one back working memory task(OWMT) were performed. The reaction time and accuracy degree were measured. The results showed that the reaction time of EVAT was the fastest and the accuracy degree of attention task was the highest in green environment. The reaction time of OWMT was the fastest in yellow and the accuracy degree of memory task was the highest in blue. For physiological parameters, we measured electrocardiogram(ECG) and HRV spectrum analysis, HF/LF color environment. These results can be used as an indicator in the design of color environment and clinical applications.

In this paper, we present the development of a new training system for equilibrium sense and postural control. This system consists of an unstable platform, a force plate, a computer, and training programs. The unstable platform provides 360 degrees of movement allowing for training in all directions. To evaluate the effects of the training system, weperformedvariousexperimentstotraintheabilityofequilibrium sense and postural control of fifteen young healthy subjects. We measured the time a subject maintains his or hercenterofpressure on atarget, the time a subject moves his or her center of pressure to a target, and the mean absolute deviation of thetracebefore and after the training. We analyzed these parameters obtained before and after the training using paried-sample T-test. The result shows that the subjects experienced distinctive enhancement in their ability of postural control through the training using oursystem.

In situations of spatio-temporal perception about visuo-auditory stimulus, researches propose optimal integration hypothesis that perceptual process is optimized to the interaction of the senses for the precision of perception. So, when the visual information considered generally dominant over any other sense is ambiguous, the information of the other sense like auditory stimulus influences the perceptual process in interaction with visual information. Thus, we performed two different experiments to certain the conditions of the interacting senses and influence of the condition. We consider the interaction of the vi suo-auditory stimulation in the free space, the color of visual stimulus and sex difference of testee with normal people. In first experiment, 12 participants were asked to judge the change in the frequency of audio-visual stimulation using a visual flicker and auditory flutter stimulation in the free space. When auditory temporal cues were presented, the change in the frequency of the visual stimulation was associated with a perceived change in the frequency of the auditory stimulation as the results of the previous studies using headphone. In second experiment, 30 male and 30 female were asked to judge the change in the frequency of audio-visual stimulation using a color of visual flicker and auditory flutter stimulation. In the color condition using red and green. Both male and female testees showed same perceptual tendency. male and female testees showed same perceptual tendency however, in case of female, the standard deviation is larger than that of male. This results implies that audio-visual asymmetry effects are influenced by the cues of visual and auditory information, such as the orientation between auditory and visual stimulus, the color of visual stimulus.

In this paper, we propose a new training system for the improvement of equilibrium sense using unstable platform. The equilibrium sense, which provides orientation with respect to gravity, is important to integrate the vision, somatosensory and vestibular function to maintain the equilibrium sense of the human body. In order to improve the equilibrium sense, we developed the software program such as a block game, pingpong game using Visual C++. These training system for the equilibrium sense consists of unstable platform, computer interface and software program. The unstable platform was a simple structure of elliptical-type which included tilt sensor, wireless RF module and the device of power supply. To evaluate the effect of balance training, we measured and evaluated the parameters as the moving time to the target, duration to maintain cursor in the target of screen and the error between sine curve and acquired data. As a results, the moving time to the target and duration to maintain cursor in the target was improved through the repeating training of equilibrium sense. It was concluded that this system was reliable in the evaluation of equilibrium sense. This system might be applied to clinical use as an effective balance training system