• Journal of Korean Institute of Industrial Engineers
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• v.27 no.4
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• pp.413-423
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• 2001

Low back disorders (LBDs) are one of the most common and costly work-related musculoskeletal disorders. One of the major possible risk factors of LBDs is to work with static and awkward trunk postures, especially in a complex trunk posture involving flexion, twisting and lateral bending simultaneously. This study is to examine the effect of complex trunk postures on the postural stresses using a psychophysical method. Twelve healthy male students participated in an experiment, in which 29 different trunk postures were evaluated using the magnitude estimation method. The results showed that subjective discomfort significantly increased as the levels of trunk flexion, lateral bending and rotation increased. Significant interaction effects were found between rotation and lateral bending or flexion when the severe lateral bending or rotation were assumed, indicating that simultaneous occurrence of trunk flexion, lateral bending and rotation increases discomfort ratings synergistically. A postural workload evaluation scheme of trunk postures was proposed based on the angular deviation levels from the neutral position. Each trunk posture was assigned numerical stress index depending upon its discomfort rating, which was defined as the ratio of discomfort of a posture to that of its neutral posture. Four qualitative action categories for the stress index were also provided in order to enable practitioners to apply corrective actions appropriately. The proposed scheme is expected to be applied to several field areas for evaluating trunk postural stresses.

• The Journal of Korean Physical Therapy
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• v.13 no.1
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• pp.127-137
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• 2001

Low back pain is significant problem in today's society, with lifetime incidence rate reported between 50% and 90%. Many factors associated with LBP are reported. The purpose of this studies were to be evaluated static standing posture aberrations in chronic LBP in comparison with healthy individuals. The samples including 80 subjects recruited to the following two groups:patients and control(normal) Questionnaires were completed by 40 LBP patients and 40 controls at the department of Physical Therapy, Saejong neurosurgical clinic in Taegu city from October 1, 1999 to March 30, 2000. The angle of lumbar lordosis was measured on lateral x-ray films with standing position. In LBP groups. the mean degree of lumbar lordosis, sacral inclination, and lumbosacral joint angle were 29.9 ${\pm}$ 9.3, 34.8 ${\pm}$ 8.2, and 12.7 ${\pm}$ 5.7 respectively. Control groups, the mean degree of lumbar lordosis, sacral inclination and lumbosacral joint angle were 35.3 ${\pm}$ 7.8, 34.9 ${\pm}$ 6.4 and 12.5 ${\pm}$ 4.3 respectively. there were significantly decreaseds in lumbar lordosis in Low back pain group. lumbar lordosis on the working posture had significant differences among groups(sitting position patients 31.4 ${\pm}$ 9.3, standing position patients 29.4 ${\pm}$ 9.3, sitting position control 35.0 ${\pm}$ 6.4, standing position control 35.5 ${\pm}$ 8.8, respectively) (p=0.034). sacral inclination on the working posture had differences among groups(sitting position patients 35.9 ${\pm}$ 8.7.standing position patients 33.6 ${\pm}$ 7.6, sitting position control 33.9 ${\pm}$ 5.9. standing position control 35.6 ${\pm}$ 6.8, respectively). lumbersacral joint angle on the working Posture had differences among groups(sitting position patients 12.0 ${\pm}$ 5.6, standing position patients 13.4 ${\pm}$ 5.9, sitting position control 11.2 ${\pm}$ 3.0. standing position control 13.4$^{\circ}$, respectively).

• Physical Therapy Korea
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• v.13 no.1
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• pp.9-15
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• 2006

Work-related musculoskeletal disorder has been associated with long hours of computer work and prolonged periods of static posture. In clinical settings, postural correction is a common treatment approach for individuals with neck, shoulder, and back pain. This study was designed to identify the effect of Forward Head Posture Correctional Device during computer work. Twelve healthy adults (mean age, 27.4 yrs; mean height, 165.0cm mean weight, 65.8 kg) participated in the study. They had no medical history of neurological or surgical problems with their upper extremity. The subjects were asked to perform Head Forward Posture under the guidance of physical therapists and the measured angles were analyzed using a 3-D motion analysis system. Markers were placed on the C7 spinous process, tragus of the ear and forward head angle was between the line from the tragus to the C7 line and the Y-axis at the C7. The statistical significance of difference between, "without" and "with" correctional device was tested by paired t-test. A level of significance was set at ${\alpha}$=.05. In comparison of the computer work between "without" and "with" correctional device, Forward Head Angle was showed significant difference (p<.05). In conclusion, the range of Forward Head Angle was significantly decreased during computer work with the correctional device. Further research is needed to understand the nature of motor control problems in deep muscles in patients with neck, shoulder, and back pain.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.81-88
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• 2011

A real time monitoring system from a PC has been developed which can be accessed through transmitted data, which incorporates an established low powered transport system equipped with a single chip combined with wireless sensor network technology from a three-axis acceleration sensor. In order to distinguish between static posture and dynamic posture, the extracted parameter from the rapidly transmitted data needs differentiation of movement and activity structures and status for an accurate measurement. When results interpret a static formation, statistics referring to each respective formation, known as the K-mean algorithm is utilized to carry out a determination of detailed positioning, and when results alter towards dynamic activity, fuzzy algorithm (fuzzy categorizer), which is the relationship between speed and ISVM, is used to categorize activity levels into 4 stages. Also, the ISVM is calculated with the instrumented acceleration speed on the running machine according to various speeds and its relationship with kinetic energy goes through correlation analysis. With the evaluation of the proposed system, the accuracy level stands at 100% at a static formation and also a 96.79% accuracy with kinetic energy and we can easily determine the energy consumption through the relationship between ISVM and kinetic energy.

• Physical Therapy Rehabilitation Science
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• v.8 no.1
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• pp.40-44
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• 2019

Objective: The purpose of this study was to examine the changes in postural stability according to ankle fixation in healthy university students. Design: Cross-sectional study. Methods: Thirty healthy subjects (15 males and 15 females, 20.13 years, 167.49 cm, 65.87 kg) were recruited on a voluntary basis. The BT4 system (HUR Laps Oy, Tampere, Finland) was used to measure the static (standing posture with eyes open and eyes closed) and dynamic (external perturbation and limits of stability (LOS) in the forward, backward, left, and right side) balance abilities. External perturbation was measured by the subject's postural sway velocity and area for 20 seconds after being impacted by a gym ball. Static and dynamic stabilities were measured with ankle joint fixation and non-fixation conditions. Ankle fixation was provided using Mueller tape on both ankle joints. Results: For static stability under the standing posture, there was no significant difference between standing with ankle joint fixation and non-fixation conditions. However, dynamic stability (external perturbation and LOS in the forward, backward, left, and right side) was significantly higher in the standing with the non-fixation condition compared to the standing with ankle joint fixation condition (p<0.05). Conclusions: Our results reveal that ankle joint fixation can influence dynamic stability during standing. Thus, we believe that this result provides basic information for making improvements in postural control and may be useful in balance training for fall prevention.

• The KIPS Transactions:PartB
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• v.18B no.5
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• pp.305-314
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• 2011

Research into the visual perception of human emotion to recognize an intention has traditionally focused on emotions of facial expression. Recently researchers have turned to the more challenging field of emotional expressions through body posture or activity. Proposed work approaches recognition of basic emotional categories from body postures using neural model applied visual perception of neurophysiology. In keeping with information processing models of the visual cortex, this work constructs a biologically plausible hierarchy of neural detectors, which can discriminate 6 basic emotional states from static views of associated body postures of activity. The proposed model, which is tolerant to parameter variations, presents its possibility by evaluating against human test subjects on a set of body postures of activities.

• The Research Journal of the Costume Culture
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• v.19 no.5
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• pp.1019-1030
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• 2011

The aim of this study was to develop a pattern of flight attendant uniform shirts to provide better comfort for their work postures. Flight attendants' work postures were evaluated to determine the problems of clothing and mobility during their work. The pattern of the flight attendants' uniform shirt was altered by applying dynamic wearing ease(DWE). DWE was calculated from four standardized dynamic postures and a static posture. An experimental garment was made with the altered postures. The researcher redesigned the pattern of the uniform shirts, which minimizes physical limitations in movements. The fit and mobility of the shirts were evaluated. Results of this study are as follows. First, the five representative work postures were selected by "clothing stress" and "repetitiveness." These postures included raised arms, twisting midriff and shoulder postures. Five representative postures were selected by using the ergonomic posture assessment device index(OWAS). Second, the experimental garment was developed by applying DWE across the back and at armhole depth, back length, and side length. Third, the fit and mobility of the experimental garments and the original uniform shirts were compared at the flight working environment set and 5 dynamic body postures of raising arms. The experimental garments made with an altered pattern provided better fit and mobility than the original sample shirts.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.2
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• pp.21-28
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• 2019

PURPOSE: This study was conducted to compare different standing postures with the use of standing aids for lumbar spine posture and muscle activity, and to identify the most desirable standing posture. METHODS: The lumbopelvic angle was assessed based on static radiographic measurement on the sagittal plane. Lumbar lordosis, lumbosacral lordosis, and the intervertebral joint angle at L1/L5 and L5/S1 were measured using radiography in three standing postures (standing on level ground, standing with one foot on a platform, and standing on a sloped surface). In addition, muscle activity was measured using surface electromyography to examine the co-contraction of the lumbar and hip muscles. RESULTS: Lumbar lordosis, lumbosacral lordosis, and L5/S1 intervertebral joint flexion occurred with one foot on the platform. No significant differences were found between standing on a sloped surface and standing on level ground. However, muscle co-contraction was reduced with the use of standing aids. CONCLUSION: This study demonstrated that standing with a foot on a platform induced lumbar lordosis, but that there was no significant difference between standing on a sloped surface and standing on level ground. However, muscle co-contraction was reduced with the use of standing aids. Based on the motor control pattern as a predictor of LBP, the use of standing aids would help workers during prolonged standing.

• Physical Therapy Korea
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• v.29 no.3
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• pp.235-240
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• 2022

Background: A spinal extension and intensive rehabilitation program reduced the symptoms and pain of kyphosis, and improved function. Objects: This study aimed to demonstrate the effect of a spine extension device on the degree of thoracic kyphosis and extension angles, confirm reduction of the kyphosis angle and an increase in flexibility. Methods: Thirteen adults were enrolled in the experiment, using the spine extension device, which was set to passively extend the spine. The angle between the spinous process of the first thoracic vertebra and the spinous process of the twelfth thoracic vertebra was measured by dual inclinometer before and after using the spine extension device. Results: In the static posture, the thoracic kyphosis decreased after using the spine extension device in the thoracic extension posture, and there was a significant difference (p < 0.05); thoracic extension angle increased with statistical significance (p < 0.05). Conclusion: In this study, the thoracic kyphosis angle and thoracic extension angle of the subjects before and after using spine extension device was compared and analyzed, which proved that the spine extension device can effectively improve the mobility of spinal extension.

• Journal of the Ergonomics Society of Korea
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• v.11 no.2
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• pp.3-13
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• 1992

Resultant compressions on the L5/S1 joint of six subjects were studied as they lif- ted light weights in sitting and standing work postures. The subjects activities were photographed and analysed later by a static biomechamical computer model. Statistically significant differences were found between the result of the two postures analyses. Sitting posture showed significantly high compressions on the joint when doing several material handling tasks having the same work loads from the hip joint. Therefore, it is recommended that working with light weights in standing is less hazardous than doint the same work sitting postures, although both the maximum compression forces are under the Action Limit suggested by NIOSH.