초록  In this study, the structural analysis of sway brace device for earthquake-proof which can fix a pipe installed in the building was carried out. The sway brace device was analyzed to evaluate not only the deformations of adaptor fitting, support brace member, structure attachment fitting and clamp sway brace fitting that compose it, but also the effective stress of adaptor fitting combined with support brace member by shear bolt. As a result of structural analysis, it can be seen that the deformation of support brace member influences most of the deformation of sway brace device and the design of adaptor fitting must be modified. Above all, it indicates that the sway brace device is suitable for Korea Fire Institute(KFI) approval standard since its total deformation is smaller than the maximum displacement proposed by KFI. The result of this study can be effectively used to investigate the effective stresses and deformations without the performance test of sway brace device according to its setting angle.

Background: Augmented somatosensory feedback stimulates the mechanoreceptor to deliver information on bodily position, improving the postural control. The various types of such feedback include ankle-foot orthoses (AFOs) and vibration. The optimal feedback to mitigate postural sway remains unclear, as does the effect of augmented somatosensory feedback on muscle co-contraction. Objects: We compared postural sway and ankle muscle co-contraction without feedback (control) and with either of two forms of somatosensory feedback (AFOs and vibration). Methods: We recruited 15 healthy subjects and tested them under three feedback conditions (control, AFOs, vibration) with two sensory conditions (eyes open, or eyes closed and the head tilted back), in random order. Postural sway was measured using a force platform; the mean sway area of the 95% confidence ellipse (AREA) and the mean velocity of the center-of-pressure displacement (VEL) were assessed. Co-contraction of the tibialis anterior and gastrocnemius muscles was measured using electromyography and converted into a cocontraction index (CI). Results: We found significant main effects of the three feedback states on postural sway (AREA, VEL) and the CI. The two sensory conditions exerted significant main effects on postural sway (AREA and VEL). AFOs reduced postural sway to a level significantly lower than that of the control (p = 0.014, p < 0.001) or that afforded by vibration (p = 0.024, p < 0.001). In terms of CI amelioration, the AFOs condition was significantly better than the control (p = 0.004). Vibration did not significantly improve either postural sway or the CI compared to the control condition. There was no significant interaction effect between the three feedback conditions and the two sensory conditions. Conclusion: Lower-extremity devices such as AFOs enhance somatosensory perception, improving postural control and decreasing the CI during static standing.

Stroke can cause leg weakness, sensory abnormalities, and balance disorders. The purpose of this study was to investigate the effect of elastic taping on postural sway in patients with stroke. This study randomly applied elastic taping to 20 patients with stroke in two ways. The center of pressure (COP) distribution was measured before and after the elastic taping. The measurement variables were COP area and length, and measurements were performed immediately after taping. The elastic taping on tibialis anterior muscle showed a significant decrease in COP area and length compared to that without elastic taping. The elastic taping on gastrocnemius muscles showed a significant decrease in COP area and length compared to that without elastic taping. There was no significant difference in COP area and length between the elastic taping on tibialis anterior muscle and gastrocnemius muscles. Our results suggested that applying elastic taping on the ankle joints is effective in decreasing postural sway after in patients with stroke.

Background: Posture balance control is the ability to maintain the body’s center of gravity in the minimal postural sway state on a supportive surface. This ability is obtained through a complicated process of sensing the movements of the human body through sensory organs and then integrating the information into the central nervous system and reacting to the musculoskeletal system and the support action of the musculoskeletal system. Motor function, including coordination, motor, and vision, vestibular sense, and sensory function, including proprioception, should act in an integrated way. However, more than half of stroke patients have motor, sensory, cognitive, and emotional disorders for a long time. Motor and sensory disorders cause the greatest difficulty in postural control among stroke patients. Objects: The purpose of this study is to determine the effect of visual and somatosensory information on postural sway in stroke patients and carrying out a kinematic analysis using a tri-axial accelerometer and a quantitative assessment. Methods: Thirty-four subjects posed four stance condition was accepted various sensory information for counterbalance. This experiment referred to the computerized dynamic posturography assessments and was redesigned four condition blocking visual and somatosensory information. To measure the postural sway of the subjects’ trunk, a wireless tri-axial accelerometer was used by signal vector magnitude value. Ony-way measure analysis of variance was performed among four condition. Results: There were significant differences when somatosensory information input blocked (p<.05). Conclusion: The sensory significantly affecting the balance ability of stroke patients is somatosensory, and the amount of actual movement of the trunk could be objectively compared and analyzed through quantitative figures using a tri-axial accelerometer for balance ability.

The purpose of this study to identified the effect of muscle strengthening of ankle joints on postural sway. The subjects of this study were 29 healthy adults aged between 20 and 30 years(male 18, female 11). All subjects received ankle muscle strengthening exercise for 3 times, 3 sessions, 30 minutes per week over 4weeks period. The measured item of muscle strength, postural sway. Data collected from all subjects the result were as follows. The ankle strength showed significant increase(p<.05). One leg stand test with eye close increase in static balance(p<.05), left-right sway distance and anterior-posterior sway distance with eye open and close in static balance(p<.05). The result findings show that strength of the ankle joint muscles is a factor which affects postural sway and the ankle joints are important in static balance.

본 연구에서는 도시부도로의 곡선구간에서 주행차량의 횡방향 이격량을 분석하여 차량 주행에 필요한 최소 소요차로폭을 산정하였으며 본 연구결과와 선행연구에서 제시된 직선구간에서의 최소 소요차로폭을 비교 분석하였다. 이를 바탕으로 도로의 선형과 차종에 따라 곡선구간에서의 최소 소요차로폭을 제시하였다. 조사대상 곡선구간 도로의 차로폭은 2.79m~3.40m이다. 주행차량의 횡방향 이격량의 분포 및 조사대상 차량의 85%를 기준으로 누적분포를 분석하였다. 분석결과 곡선구간에서의 최소 소요차로폭이 소형차량의 경우 2.31m~2.58m, 대형차량의 경우 2.80m~3.27m로 산정되었다. 본 연구결과는 녹색교통 도입을 위한 공간, 도로공사 중, 소형차 전용도로의 건설 등에 활용될 수 있을 것이다. 또한 설계자의 목적에 따라 유연한 차로폭 설계기준의 적용에 필요한 기초적인 연구로 활용될 수 있을 것으로 기대된다.

We investigated the effects of trunk twist on postural stability during manually handling flat ties. Ten male subjects participated in this study. While handling 5kgf and 10kgf bundles of flat ties respectively, their centers of pressure (COPs) were measu

The purposes of this study were to assess variation of body sway prior to and after submaximal treadmill exercise; to determine the time course of the effects of a fatiguing performed on a treadmill on body sway; and to compare position sense prior to and after exercise in order to assess any variance in proprioception caused by submaximal treadmill exercise. The subjects were twenty-four healthy men in their twenties. They stood barefoot on the Kinesthetic Ability Training Balance Platform to measure body sway. Control trials were performed with eyes alternately open and closed. In the eyes open condition, they were asked to look at a target placed at eye level 1 m in front them. A total of 10 trials, each lasting 20 seconds, were performed. After this series of trials, position sense was measured. Subjects then exercised on the treadmill until 85% of each person's maximal heart rate was reached. The first series of postural sway measurements began immediately after this exercise. The second identical series of postural sway trials was performed at approximately 10 minutes after exercise. The third series was performed approximately 20 minutes after exercise. This allowed approximately 5 minutes of rest between each experimental series. Position sense was measured at approximately 15 and 25 minutes after exercise. The results were as follows: 1) There was a significant increase in body sway after submaximal treadmill exercise compared to pre-exercise values under both visual conditions (p<.05). 2) After submaximal treadmill exercise, under the eyes open condition, the mean value of body sway was significantly increased after both the first and second series (p<.05). Under the eyes closed condition, the mean value of body sway increased significantly after the first series but decreased significantly after the third series (p<.05). 3) Position sense, measured repeatedly after submaximal treadmill exercise, did not change significantly with respect to pre-exercise values (p>.05). These results suggest that fatigue induced by submaximal treadmill exercise produced an increase in body sway in young healthy subjects with or without visual input, but the increase appeared to be lasting less than 15 minutes. No significant change in position sense suggested that proprioception was unaffected by submaximal treadmill exercise-induced fatigue.

To improve the effect of balance training, visual feedback is usually used. During the training process there are some factors which decrease the effect. Neurophysiologically, the main negative factor is thought to be synaptic fatigue which decreases the sensitivity of synapses. The purpose of this study was to find a more effective balance training method. In this study, a total of 60 normal subjects-19~30 years old young males and females(M=30, F=30)-participated, and they were randomized as A, B, and C group, each group containing 20 subjects. First, all groups had a pre-test of sway balance. One minute later, A group was trained in sway balance by continuous visual feedback for 2 minutes, B group by intermittent visual feedback which had 4 sessions of 30 seconds each and a one minute rest break. C group was not trained at all. All groups had a post-test. Only B group had improved balance compared with C group by ANOVA. On the other hand, intermittent visual feedback was more effective than continuous visual feedback in sway balance training with normal subjects.ㅂ

이 논문의 주목적은 정상인을 대상으로 각기 다른 3가지의 (체중의 1.5 %, 3.0 %, 9.0 %) 부하를 통해서 자세의 불균형을 유발시켰을 때 나타나는 postural movement patterns을 기술하기 위한 연구이다. 연구대상의 허리중심에 체중부하를 주어 균형이 뒤로 이동하게 하여, surface EMG(표면 근전도)를 통하여 Tibialis anterior(Ta), Gastrocnernius(Gc), Quadriceps femoris(Q

다이나믹 시스템 관점에 따르면 직립자세를 취하는 동안 발생하는 자세 흔들림은 단순히 불필요한 소음이 아닌 안정된 자세균형을 위해 필수적인 기능을 한다. 전후와 좌우 방향의 자세 흔들림 중 어느 한방향이 초자세적 과제 요구로 인해 고정 또는 감소시켜야 할 때 균형유지를 위한 탐색과 수행 기능을 위해 또 다른 방향의 자세 흔들림은 증가시켜야 한다. 본 연구는 초자세적 과제 요구로서 권총조준 과제를 사용하여 이 가설을 검증하였다. 열 명의 피험자들은 표적을 향해 측면 또는 정면자세로 서서 권총으로 가까운 거리(3m)와 먼 거리(10m)에 위치한 표적을 향해 조준선 정열을 하도록 요구되었다. 표적거리의 차이에 따른 전후와 좌우 방향의 자세 흔들림의 변화 크기를 압력판 시스템을 사용하여 측정하였다. 분석결과 측면과 정면자세 모두에서 표적거리가 증가했을 때 피험자들의 좌우와 전후 방향의 자세 흔들림의 크기는 유의하게 증가 또는 감소되지 않았다. 표적거리에 따른 자세 흔들림의 변화 크기가유의함에는 미치지는 못했지만 자세 흔들림의 변화 형태는 본 연구의 가설과 일치했다. 본 연구의 결과는 권총조준을 수행하는 동안 정확도와 자세균형의 요구를 충족시키기 위해 전후와 좌우 방향의 자세흔들림이 서로 보상적 관계로 작용한다는 본 연구의 가설을 부분적으로 지지한다. 유의함에 미치지 못한 표적거리 효과는 제한된 범위의 표적거리 조건과 권총사격의 특성에 비추어 논해진다.

본 연구의 목적은 권총 조준을 수행하는 동안 발생하는 자세 흔들림에 대해 시각정보가 어떤 영향을 미치는지 조사하는데 있었다. 열 명씩의 같은 연령대의 오른손잡이 여대생들과 사격 선수들은 시각정보의 조건이 서로 다른 세 가지 과제를 수행하도록 요구되었다. 첫 번째 과제는 표적을 향해 측면으로 서서 10m 거리에 위치한 표적을 주시하는 것이었고, 두 번째 과제는 동일한 자세로 같은 위치의 표적을 향해권총으로 조준선 정렬을 수행하는 것이었다. 세 번째 과제는 레이저 빔이 분출되는 권총으로 동일한 표적을 조준하는 것이었다. 과제의 수행 동안 피험자가 나타낸 전후와 좌우 방향의 자세 흔들림의 크기를 측정하기 위해 압력판 시스템이 사용되었다. 분석결과 일반 대학생들이 나타낸 전후와 좌우 방향의 자세흔들림의 크기는 모든 과제의 수행에서 유의한 차이를 나타내지 않았다. 반면 사격선수의 경우 좌우 방향의 자세 흔들림에 대한 과제 효과는 유의하지 않았으나 전후 방향의 자세 흔들림은 과제의 차이에 따라 유의한 변화를 나타냈다. 레이저 빔이 분출되는 권총으로 조준을 하였을 때 전후 방향의 자세 흔들림은 가장 작았다. 또한 사격자세로 서서 표적을 주시할 때와 비교해 권총으로 조준선 정렬을 수해하였을 때 전후 방향의 자세 흔들림은 더 작았다. 현재의 결과는 조준을 수행하는 동안 사격선수와 일반인은 서로 다르게 시각정보를 사용하고 있음을 나타낸다. 그리고 시각정보 사용의 차이는 자세 흔들림의 정확도유지 기능과 연관이 있는 것처럼 보인다. 레이저 빔의 움직임에 대한 시각정보는 권총 조준의 정확도를 향상시킨다. 그러나 그 효과는 시각정보를 사용하는 능력의 차이로 인해 숙련자에게만 유효하다.