• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.39-46
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• 2016

Loss of postural stability can possibly lead to slip and fall accidents in the number of workplaces and everyday life. This study was aimed to examine the effects of whole body fatigue and partially limited visual field on the ability of maintaining postural balance during quiet standing. A group of twelve healthy male subjects participated in the experiment. Before and after experiencing the whole body fatigue induced by bicycling exercises, the position coordinates of subject's center of pressure (COP) were obtained under the two levels of visual field condition (i.e., open visual field and limited visual field). Four levels of the whole body fatigue examined were rest, 300watt, 600watt, and 900watt. Position coordinates of COPs measured on a force plate were then converted into the total length of postural sway path in both the medio-lateral (ML) direction and the anterior-posterior (AP) direction. Two-way ANOVA result showed that the length of sway path in the AP direction became significantly larger as the whole body fatigue accumulated. Post-hoc test revealed statistically significant differences between rest and 900watt and between 300watt and 900watt. The significant increase of the sway length was also found when the visual field was partially obstructed by the boxes. In the ML direction, however, there was no statistically significant difference of the postural sway in both the AP and ML directions. The results imply that the ability of maintaining postural stability can be reduced significantly due to such tasks along with whole body fatigue. The postural balance can also be impaired by the limited visual field.

• Physical Therapy Rehabilitation Science
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• v.4 no.2
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• pp.103-107
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• 2015

Objective: Pelvic floor muscles (PFMs) form the base of the abdomino-pelvic cavity and also the PFMs function is important for urinary continence. PFMs training (PFMT) is considered to be the first method for PFM dysfunction. This study demonstrated correct PFMs contraction among commonly used different contraction methods for PFMT. Design: Cross-sectional study. Methods: In this study, nineteen middle-aged (40-70 years) women participated. To evaluate PFM function, ultrasonography was used to measure the distance of the bladder base movement. The distance of the PFM movements were calculated at rest and during the other contractions. The following four different contraction methods were performed randomly: (1) PFM contraction, (2) abdominal drawing-in maneuver (ADIM), (3) anal contraction, and (4) hip adductor muscle contraction. The participants held the contraction for 3 seconds for a total of 3 times with a 30 seconds rest period between each trial. The mean of three measurements in each position were obtained and compared with that in the resting position. Results: The bladder base movement values were significantly greater when comparing PFM with ADIM and hip adductor contractions (p<0.05). The bladder base movement values were significantly greater when comparing ADIM and anal contractions with hip adductor contractions (p<0.05). Conclusions: The results of this study suggest that performing PFM contractions is the best method among the common methods for PFMT. Performing PFM contractions was more effective than the other contraction methods.

• Journal of the Ergonomics Society of Korea
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• v.30 no.3
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• pp.381-387
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• 2011

Objective: The aim of this study was to investigate the maximal grip strength for the combinations of resting time and trial and to provide guideline of resting time for the maximum gripping task associated with the number of trials. Background: Despite many previous researches for the maximal grip strength, few studies have considered the effect of both trials and rest time on the maximum grip strength. Methods: A total of thirty subjects participated in the study. The average of maximum grip strength was measured using JAMAR hydraulic hand dynamometer. The testing position was same as the position recommended by the American Society of Hand Therapists. The between-subject experimental design has been conducted in this study. Trials(1~20 trials) and rest time(2, 3, and 4min) were considered as independent variables, and the maximum grip strength was considered as dependent variable, respectively, in this study. Results: According to the result of the number of trials, the maximal grip strength decreased gradually as the number of trials increased. The ANOVA result showed that the main effect was significant for both resting time(p<.0001) and trial(p<.0001), and the interaction was significant(p<0.0086). Conclusions: The maximal grip strength decreased gradually as the number of trials increased. Thus, basic guideline of resting time was suggested for the number of trials of maximal grip strength tests in this study.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.1
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• pp.173-181
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• 2021

Purpose : The purpose of this study is to compare muscle activity after applying two muscle energy techniques (MET) to subjects with forward head posture to see if the post isometric relaxation (PIR) technique is more effective than the reciprocal inhibition (RI) technique. Methods : The muscle activity was measured using EMG after applying the PIR and RI techniques to 30 adults at K College. Subjects were selected for forward head posture whose ear center was 2.5 ㎝ front of the center of the shoulder. EMG equipment was used to measure muscle activity, and the measurement sites were measured in cervical flexor and extensor muscles. The experiment period was performed once a week for a total of two weeks, and after the pre-measurement was performed for 5 minutes PIR and RI exercise. In the PIR technique, the head is tilted back in a sitting position, and the experimenter applies resistance with the same force for 7~10 seconds and repeats 3-5 times after rest. In the RI technique, in a sitting position, the subject gives the force to bend the head forward, and the experimenter applies resistance with the same force for 7 to 10 seconds, and repeats 3 to 5 times after rest. Results : The result is same as the following. In the comparison of muscle activity, there was a significant decrease in both PIR and RI at 1 and 2 weeks. And there was a greater decrease in muscle activity in PIR. There was no difference in the comparison of decrease in muscle activity at 1 week and 2 week. Conclusion : Both PRI and RI can be said to be effective in improving the function of the forward head posture in the neck muscles. Therefore, the selection of the two techniques in clinical practice should be appropriately performed under the judgment of experts according to the patient's situation.

• Journal of Korean Neurosurgical Society
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• v.64 no.5
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• pp.799-807
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• 2021

Objective : Cerebrospinal fluid leakage related complications (CLC) occasionally occur after intradural spinal surgery. We sought to investigate the effectiveness of early ambulation after intradural spinal surgery and analyze the risk factors for CLC. Methods : For this retrospective cohort study, we enrolled 314 patients who underwent intradural spinal surgery at a single institution. The early group contained 79 patients who started ambulation after 1 day of bedrest without position restrictions, while the late group consisted of 235 patients who started ambulation after at least 3 days of bed rest and were limited to the prone position after surgery. In the early group, Prolene 6-0 was used as the dura suture material, while black silk 5-0 was used as the dura suture material in the late group. Results : The overall incidence rate of CLC was 10.8%. Significant differences between the early and late groups were identified in the rate of CLC (2.5% vs. 13.6%), surgical repair required (1.3% vs. 7.7%), and length of hospital stay (2.99 vs. 9.29 days) (p<0.05). Logistic regression analysis revealed that CLC was associated with practices specific to the late group (p=0.011) and the revision surgery (p=0.022). Conclusion : Using Prolene 6-0 as a dura suture material for intradural spinal surgery resulted in lower CLC rates compared to black silk 5-0 sutures despite a shorter bed rest period. Our findings revealed that suture - needle ratio related to dura defect was the most critical factor for CLC. One-day ambulation after primary dura closure using Prolene 6-0 sutures appears to be a costeffective and safe strategy for intradural spinal surgery.

• PNF and Movement
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• v.18 no.3
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• pp.415-424
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• 2020

Purpose: This study aimed to compare changes in abdominal muscle thickness in different standing postures with a handheld load between subjects with and without chronic low back pain (CLBP). Methods: Twenty subjects with CLBP and 20 controls participated in this study. Ultrasound imaging was used to assess the changes in the thickness of the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles. Muscle thickness in three different standing postures (standing at rest, standing with loads, standing with lifting loads) was compared with the muscle thickness at rest in the supine position and was expressed as a percentage of change in the thickness of the muscle. Results: While standing with loads, the change in IO muscle thickness in the CLBP patients increased more significantly than in the pain-free controls (p < 0.05). The standing with lifting loads posture showed a significant increase in the change in thickness of the TrA compared with the standing with loads posture (p < 0.05). In addition, the standing with lifting loads posture showed a significant decrease in the change in the thickness of the EO when compared with the standing with loads posture (p < 0.05). Conclusion: The automatic activity of the IO muscle in subjects with CLBP increased more than that of the pain-free controls in the standing with loads posture. These findings suggest that IO muscle function may be altered in those with CLBP while standing with loads. Additionally, TrA the activation level was found to be associated with increased postural demand caused by an elevated center of mass.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.3
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• pp.243-248
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• 2014

PURPOSE: This study was aim to the change of muscle activities of lower extremity and waist during lifting a small object on the floor according to different foot position of women in their twenties wearing a skirt. METHODS: 9 women in their twenties wearing a skirt were selected and were measured the muscle activities of medial gastrocnemius (MG), tibialis anterior (TA), vastus lateralis (VL) and iliocostalis (IC) when they lifted a small object on the floor. The two different foot position employed were "both feet posed straight side by side" (condition 1) and "both feet posed diagonally to 45 degree" (condition 2) used. The order of feet position was selected randomly and the subject took a rest for 30 min between tests to prevent muscle fatigue. We calculated the mean and standard deviation of muscle activities and used Mann-Whitney U test to compare the difference between the two foot positions with SPSS(IBM Korea) RESULTS: The muscle activity of condition 2 was greater than that of condition 1 in right side of TA, VL, and IC and left side of TA, VL, MG and IC. The right side of TA, VL and left side VL were significant difference between condition 1 and condition 2(p<.05). CONCLUSION: We suggest "both feet posed straight side by side" position is better if a woman wearing a skirt lift the small object and it will help prevent the low back and lower limb problems in the future.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.10
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• pp.140-147
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• 1998

The dynamic behavior of elastically restrained beams under the action of distributed tangential forces is investigated in this paper. The beam, which is fixed at one end, is assumed to rest on an intermediate spring support. The governing equations of motion are derived from the energy expressions, and the finite element formulation is employed to calculate the critical distributed tangential force. Jump phenomena for the critical distributed tangential force and instability types are presented for various spring stiffnesses and support positions. Stability maps are generated by performing parametric studies to show how the distributed tangential forces affect the frequencies and the stability of the system considered. Through the numerical simulations, the following conclusioils are obtained: (i) Only flutter type instability exists for the dimensionless spring stiffness K $\leq$ 97, regardless of the position of the spring support. (ii) For the dimensionless spring stiffness K $\leq$ 98, the transition from flutter to divergence occurs at a certain position of the spring support, and the transition position moves from the free end to the free end of the beam as the spring stiffness increases. (iii) For K $\leq$ 10$^{6}$ the support condition can be regarded as a rigid support condition.

• The Journal of Korean Academy of Prosthodontics
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• v.21 no.1
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• pp.67-72
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• 1983

Path of insertion(1) can be defined that the direction of movement of an appliance from the point of initial contact of its rigid parts with the supporting teeth to the place of final rest. Krol(2) described that in the conventional path of insertion, all the rests are seated more or less simultaneously but in the use of the rotational path one segment of the partial denture is seated first then the remainder of the prosthesis is rotated into position. The rotational path of insertion is limited primarily to the tooth borne prosthesis. Its great advantages are the elimination of anterior clasps to improve ethetic and reduction of tooth coverage to minimize plaque accumulation. Either a rigid minor connector or proximal plate provides retention through its intimate contact with a proximal tooth surface below the height of contour as indicated at a o-degree tilt. A specially designed rest in conjunction with this retentive component satisfies the basic requirements of clasp design. The purpose of this study was a clinical evaluation of rotational path removable partial dentures. Author delivered rotational path removable partial dentures to three different cases of patients and evaluated function of the dentures, difficulties of removal and insertion of the dentures and supporting structures of the abutment teeth by means of clinical and X-ray examinations for eighteen months. According to the examination data author came to the conclusion that the prognosis of the rotational path removable partial dentures was excellent.

• Journal of radiological science and technology
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• v.42 no.3
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• pp.195-199
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• 2019

Most of the vascular procedures performed for various diagnoses and treatments of various abdominal intervention procedures performed by the Department of Radiology and Angiography are performed by puncture of the femoral artery. For this reason, patients should undergo blood-related tests such as prothrombin time (PT) and partial thromboplatin time (PTT). Therefore, many patients are instructed to take precautions such as putting a sandbag on the puncture site to prevent delayed hemorrhage after hemostasis of the femoral artery puncture site, and not to bend the leg of the treated area for about 3 hours. Because of this, many patients have complained of pain during the procedure and inconvenience during the absolute bed rest time in the ward. The purpose of this study was to compare the safety of balloon ancillary devices with sandbags placed on the hemostasis site to prevent delayed hemorrhage after arterial puncture. We compared the safety of each patient with the results of medical records in consideration of the problem that the patient could not press with the focus, the position of the patient was changed depending on the patient's body shape, and the problem of falling down according to the location of the puncture site. As a result, the use of a balloon type ancillary device improves the effect of continuous hemostasis, reduces discomfort during the patient's absolute stabilization time, increases the patient's satisfaction, and is a good alternative to the existing sandbag.