• PNF and Movement
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• 제22권1호
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• pp.31-41
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• 2024

Purpose: The purpose of this study is to compare lower extremity muscle activities and ankle joint angles between different foot strike patterns (forefoot strike, heelfoot strike) during stair ascent walking. Methods: The subjects of this study were 22 males who walked in each foot strike pattern on ascent stairs at a speed of 85 beats/min. During stair walking with the two types of foot strike patterns, the muscle activities of the rectus femoris, tibialis anterior, medial gastrocnemius, hamstring, and gluteus medius were measured. Additionally, ankle joint angles for inversion, eversion, dorsi flexion, and plantar flexion were recorded. Each participant underwent the experiment three times, with the foot strike pattern randomized. Results were averaged according to the foot strike pattern. Results: Significant differences in ankle angles were observed across all phases according to foot strike pattern. Muscle activities in the lower extremities showed significant differences in all phases except the swing 1 phase. Moreover, differences in foot movement trajectory were noted depending on the foot strike pattern. Conclusion: Walking on ascent stairs elicited differences in lower extremity muscle activities and ankle joint angles based on foot strike pattern. These findings can serve as foundational data for selecting a suitable foot strike pattern tailored to individual patient conditions when training patients in walking on ascent stairs.

• 한국운동역학회지
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• 제33권4호
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• pp.164-174
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• 2023

Objective: The aim of this study was to quantitatively analyze the impact characteristics of the lower extremity on strike pattern during running. Method: 19 young subjects (age: 26.53 ± 5.24 yrs., height: 174.89 ± 4.75 cm, weight: 70.97 ± 5.97 kg) participated in this study. All subjects performed treadmill running with fore-foot strike (FFS), mid-foot strike (MFS), and rear-foot strike (RFS) to analyze the impact characteristics in the lower extremity. Impact variables were analyzed including vertical ground reaction force, lower extremity joint moments, impact acceleration, and impact shock. Accelerometers for measuring impact acceleration and impact shock were attached to the heel, distal tibia, proximal tibia, and 50% point of the femur. Results: The peak vertical force and loading rate in passive portion were significantly higher in MFS and FFS compared to FFS. The peak plantarflexion moment at the ankle joint was significantly higher in the FFS compared to the MFS and RFS, while the peak extension moment at the knee joint was significantly higher in the RFS compared to the MFS and FFS. The resultant impact acceleration was significantly higher in FFS and MFS than in RFS at the foot and distal tibia, and MFS was significantly higher than FFS at the proximal tibia. In impact shock, FFS and MFS were significantly higher than RFS at the foot, distal tibia, and proximal tibia. Conclusion: Running with 3 strike patterns (FFS, MFS, and RFS) show different impact characteristics which may lead to an increased risk of running-related injuries (RRI). However, through the results of this study, it is possible to understand the characteristics of impact on strike patterns, and to explore preventive measures for injuries. To reduce the incidence of RRI, it is crucial to first identify one's strike pattern and then seek appropriate alternatives (such as reducing impact force and strengthening relevant muscles) on that strike pattern.

• 한국의료질향상학회지
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• 제10권1호
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• pp.20-27
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• 2003

Background : The doctors' strike was not only a manmade disaster but also a chance to apply a new pattern of emergency medical service for patients. We hope to propose a new pattern of emergency medical service by comparing the patterns of emergency medical service given by resident and staff during the doctors' strike. Methods : We reviewed the medical records of patients who received emergency medical service in the Emergency Department(ED) of Deagu Catholic University Hospital during 3 days a week prior to the residents' strike (July 21-23, 2000) with those of patients receiving emergency medical service during the first 3 days of the residents' strike (July 28-30, 2000). We evaluated the patient's severity, the cause of the ED visit, the performance on the laboratory study, ECG, and radiological study, the disposition, and the length of ED stay. Also, we compared the collected data by presenting doctor and by patient's severity. Results : The staff performed fewer tests admitted fewer emergent and non-emergent patients than the residents. Also, the length of ED stay was shorter in both the emergent (212.76 vs. 321.40 minutes) and the non-emergent groups (117.68 vs. 171.39 minutes) for patients presenting to staff. Conclusion : It is desirable that emergency medical service is given by staff, not by resident.

• Geomechanics and Engineering
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• 제33권5호
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• pp.477-486
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• 2023

In the studies on fault dislocation of tunnel, existing literatures are mainly focused on the problems caused by normal and reverse faults, but few on strike-slip faults. The paper aims to research the deformation and failure mechanism of a tunnel under strike-slip faulting based on a model test and test-calibrated numerical simulation. A potential faulting hazard condition is considered for a real water tunnel in central Yunnan, China. Based on the faulting hazard to tunnel, laboratory model tests were conducted with a test apparatus that specially designed for strike-slip faults. Then, to verify the results obtained from the model test, a finite element model was built. By comparison, the numerical results agree with tested ones well. The results indicated that most of the shear deformation and damage would appear within fault fracture zone. The tunnel exhibited a horizontal S-shaped deformation profile under strike-slip faulting. The side walls of the tunnel mainly experience tension and compression strain state, while the roof and floor of the tunnel would be in a shear state. Circular cracks on tunnel near fault fracture zone were more significant owing to shear effects of strike-slip faulting, while the longitudinal cracks occurred at the hanging wall.

• 자원환경지질
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• 제33권6호
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• pp.547-556
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• 2000

The purpose of this study is to analyze shear fracture system using landslide location occurred 1998 at Janghung area. For the geological implication, foliation was surveyed and analyzed, and location of landslide, geological structure and topography were constructed into spatial database using GIS. With the constructed spatial database, shear fracture system was assessed by the relation analysis between strike and dip of the foliation and aspect and slope of the topography. We compared strike and dip of foliation and aspect and slope of topography and recognized the typical fracture pattern, strike and dip of joint, that coincided with shear fracture system. The result tells us that foliation of gneiss has geometrical relation to joint or fault that leading landslide. GIS was used to analyze vast data efficiently and the result can be used to assess the landslide susceptibility as important factor.

• 한국운동역학회지
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• 제13권2호
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• pp.161-173
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• 2003

This study was performed to investigate the kinematic and kinetic differences between functional walking shoe(FWS) and general sports shoe(GSS). The subjects for this study were 4 male adults who had the walking pattern of rearfoot strike with normal feet. The movement of one lower leg was measured using force platform and 3 video cameras while the subjects walked at the velocity of 2/1.5 m/s. The findings of this study were as follows 1. The angle of lower leg-ground and angle of knee with FWS was greater than with GSS at the moment of strike the floor and the moment of second peak ground reaction force. The decreasing rate of angle of ankle was smaller in FWS from the strike phase to the second peak ground reaction force. These mean upright walking and round walking along the shoe surface. 2. The maximal Increased angle of Achilles tendon and the minimal decreased angle of rearfoot were smaller in FWS very significantly(p<0.001). Thus FWS prevent the excessive pronation of ankle and have good of rear-foot control. 3. The vortical ground reaction force and the rate of it to the BW were smaller in FWS statistically(p<0.001). The loading rate was smaller in FWS, too, and thess represent the reduction of load on ankle joint and prevention of injuries on it.

• 자원환경지질
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• 제16권4호
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• pp.269-276
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• 1983

단순한 사각주형(四角柱型) 물체(物體)에 대한 3차원 표준곡선을 해석하였다. 이들 표준곡선은 쌍극자배치(雙極子配置)에 대하여 적분방정식을(積分方程式) 이용한 수치계산기술(數値計算技術)로 구하였다. 전도성(電導性) 물체에 대한 IP응답(應答)은 물체의 폭과 두께의 비율에 따라서 그 패턴이 달라진다. 주향(走向)길이가 쌍극자간격(雙極子間隔)의 6배 이상이 되면 2차원의 결과와 유사하다. 또한 주향(走向)길이가 길고, 폭이 쌍극자 간격의 4배이상이 되면 층구조(層構造)(1차원) 해석도 가능하게 된다. 한편, 측선(測線)이 주향방향(走向方向)을 따라서 물체의 중심으로부터 멀어지는 효과는 물체의 깊이가 지표로부터 깊어질 때와 비슷하게 나타난다. 물체가 측선하(測線下)에서 측선과 평행(平行)한 방향으로 이동하더라도 IP패턴에는 거의 영향을 미치지 않는다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.115-115
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• 2000

A gait pattern classification method using electromyography(EMG) signal is presented. The gait pattern with four stages such as stance, heel-off, swing and heel-strike is analyzed and classified using feature parameters such as zero-crossing, integral absolute value and variance of the EMG signal. The EMG signal from Tibialis Anterior and Gastrocnemius muscles was obtained using the surface electrodes, and low-pass filtered at 10kHz. The filtered analog signal was sampled at every 0.5msec and converted to digital signal with 12-bit resolution. The obtained data is analyzed and classified in terms of feature parameters. Analysis results are given to show that the gait patterns classified by the proposed method are feasible.

• 한국운동역학회지
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• 제16권3호
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• pp.149-163
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• 2006

The purpose of this study was to compare the lower extremity's joint and segment coupling patterns between forward and backward running in subjects who were twelve healthy males. Three-dimensional kinematic data were collected with Qualisys system while subjects ran to forward and backward. The thigh internal/external rotation and tibia internal/external rotation, thigh flexion/extension and tibia flexion/extension, tibia internal/external rotation and foot inversion/eversion, knee internal/external rotation and ankle inversion/eversion, knee flexion/extension and ankle inversion/eversion, knee flexion/extension and ankle flexion/extension, and knee flexion/extension and tibia internal/external rotation coupling patterns were determined using a vector coding technique. The comparison for each coupling between forward and backward running were conducted using a dependent, two-tailed t-test at a significant level of .05 for the mean of each of five stride regions, midstance(1l-30%), toe-off(31-50%), swing acceleration(51-70%), swing deceleration(71-90), and heel-strike(91-10%), respectively. 1. The knee flexion/extension and ankle flexion/extension coupling pattern of both foreward and backward running over the stride was converged on a complete coordination. However, the ankle flexion/extension to knee flexion/extension was relatively greater at heel-strike in backward running compared with forward running. At the swing deceleration, backward running was dominantly led by the ankle flexion/extension, but forward running done by the knee flexion/extension. 2. The knee flexion/extension and ankle inversion/eversion coupling pattern for both running was also converged on a complete coordination. At the mid-stance. the ankle movement in the frontal plane was large during forward running, but the knee movement in the sagital plane was large during backward running and vice versa at the swing deceleration. 3. The knee flexion/extension and tibia internal/external rotation coupling while forward and backward run was also centered on the angle of 45 degrees, which indicate a complete coordination. However, tibia internal/external rotation dominated the knee flexion/extension at heel strike phase in forward running and vice versa in backward running. It was diametrically opposed to the swing deceleration for each running. 4. Both running was governed by the ankle movement in the frontal plane across the stride cycle within the knee internal/external rotation and tibia internal/external rotation. The knee internal/external rotation of backward running was greater than that of forward running at the swing deceleration. 5. The tibia internal/external rotation in coupling between the tibia internal/external rotation and foot inversion/eversion was relatively great compared with the foot inversion/eversion over a stride for both running. At heel strike, the tibia internal/external rotation of backward running was shown greater than that of forward(p<.05). 6. The thigh internal/external rotation took the lead for both running in the thigh internal/external rotation and tibia internal/external rotation coupling. In comparison of phase, the thigh internal/external rotation movement at the swing acceleration phase in backward running worked greater in comparison with forward running(p<.05). However, it was greater at the swing deceleration in forward running(p<.05). 7. With the exception of the swing deceleration phase in forward running, the tibia flexion/extension surpassed the thigh flexion/extension across the stride cycle in both running. Analysis of the specific stride phases revealed the forward running had greater tibia flexion/extension movement at the heel strike than backward running(p<.05). In addition, the thigh flexion/extension and tibia flexion/extension coupling displayed almost coordination at the heel strike phase in backward running. On the other hand the thigh flexion/extension of forward running at the swing deceleration phase was greater than the tibia flexion/extension, but it was opposite from backward running. In summary, coupling which were the knee flexion/extension and ankle flexion/extension, the knee flexion/extension and ankle inversion/eversion, the knee internal/external rotation and ankle inversion/eversion, the tibia internal/external rotation and foot inversion/eversion, the thigh internal/external rotation and tibia internal/external rotation, and the thigh flexion/extension and tibia flexion/extension patterns were most similar across the strike cycle in both running, but it showed that coupling patterns in the specific stride phases were different from average point of view between two running types.

• The Journal of Korean Physical Therapy
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• 제22권3호
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• pp.49-53
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• 2010

Purpose: The purpose of this study was to investigate the plantar pressure distribution between the affected and unaffected side in adult hemiplegia during gait with the use of a quad-cane. Methods: Thirty-four stroke patients from 34 to 83 years of age were enrolled in this study, and in random order, all patients were asked to walk at their most comfortable speed three times along a walkway with the use of quad-cane over a period of three days. Plantar pressure distribution was measured with regard to foot contact pattern and center of pressure (CoP) trajectories during the stance phase, progressing from heel-strike to toe-off. The F-scan system was used to compare the foot pressure of the affected and unaffected sides. Results: A significant reduction in the total contact area, the width of fore foot (FF) and hind foot (HF), and anterior/posterior (AP) CoP trajectory of the affected side was found. However, contact pressure of the hind foot on the affected side during walking increased when compared to that on the unaffected side. Conclusion: We demonstrated that plantar pressure distribution on the affected side of adult hemiplegia patients was generally poorer than that on the unaffected side when these patients walked with cane assistance. However, the use of a quad-cane was shown to increase contact pressure of the hind foot on the affected side because weight can be borne on the affected side during heel-strike with use of the cane.