• Journal of the Korean Society for Precision Engineering
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• v.25 no.11
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• pp.107-118
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• 2008

In this study, lower extremity joint kinematics and kinetics and lumbar lordosis were investigated for two different symmetrical lifting techniques(squat and stoop) using the three-dimensional motion analysis. Twenty-six male volunteers lifted boxes weighing 5, 10 and 15kg by both squat and stoop lifting techniques. There were not significant differences in maximum lumbar joint moments between the two techniques. The hip and ankle contributed the most part of the support moments during squat lifting, and the knee flexion moment played an important role in stoop lifting. The hip, ankle and lumbar joints generated power and only the khee joint absorbed power in the squat lifting. The knee and ankle joints absorbed power, the hip and lumbar joints generated power in the stoop lifting. The bi-articular antagonist muscles' co-contraction around the knee joint during the squat lifting and the eccentric co-contraction of the gastrocnemius and semitendinosus were found to be important for straightening up during the stoop lifting. At the time of lordotic curvature appearance in the squat lifting, there were significant correlations in all three lower extremity joint moments with the lumbar joint. Differently, only the hip moment had significant correlation with the lumbar joint in the stoop lifting. In conclusion, the knee extension which is prominent kinematics during the squat tilling was produced by the contributions of the kinetic factors from the hip and ankle joints(extensor moment and power generation) and the lumbar extension which is prominent kinematics during the stoop lifting could be produced by the contributions of the knee joint kinetic factors(flexor moment, power absorption, bi-articular muscle function).

• The Journal of Korean Physical Therapy
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• v.31 no.6
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• pp.333-338
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• 2019

Purpose: Although previous studies on the screw-home movement (SHM) for autopsy specimen and walking of living persons conducted, the possibility of acquiring SHM based on inertial measurement units received little attention. This study aimed to investigate the possibility of measuring SHM for the non-weighted bearing using a micro-electro-mechanical system-based wearable motion capture system (MEMSS). Methods: MEMSS and camera-based motion analysis systems were used to obtain kinematic data of the knee joint. The knee joint moved from the flexion position to a fully extended position and then back to the start point. The coefficient of multiple correlation and the difference in the range of motion were used to assess the waveform similarity in the movement measured by two measurement systems. Results: The waveform similarity in the sagittal plane was excellent and the in the transverse plane was good. Significant differences were found in the sagittal plane between the two systems (p<0.05). However, there was no significant difference in the transverse plane between the two systems (p>0.05). Conclusion: The SHM during the passive motion without muscle contraction in the non-weighted bearing appeared in the entire range. We thought that the MEMSS could be easily applied to the acquisition of biomechanical data on the knee related to physical therapy.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.10 no.2
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• pp.119-123
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• 1999

Background and Objectives : Conditions such as muscle atrophy, stretching of strap muscles, and continued craniofacial growth factors have been cited as contributing to the changes observed in the vocal tract structure and function in elderly speakers. The purpose of the present study is to compare F$_1$ and F$_2$ frequency levels in elderly and young adult male and female speakers producing a series of vowels ranging from high-front to low-back placement. Material and Methods : The subjects were two groups of young adults(10 males, 10 females, mean age 21 years old range 19-24 years) and two groups of elderly speakers(10 males, 10 females, mean age 67 years : range 60-84 years). Each subject participated in speech pathologist to be a speaker of unimpared standard Korean. The headphone was positioned 2 cm from the speakers lips. Each speaker sustained the five vowels for 5 s. Formant frequency measures were obtained from an analysis of linear predictive coding in CSL model 4300B(Kay co). Results : Repeated measure AVOVA procedures were completed on the $F_1$ and $F_2$ data for the male and female speakers. $F_2$ formant frequency levels were proven to be significantly lower fir elderly speakers. Conclusions : We presume $F_2$ vocal cavity(from the point of tongue constriction to lip) lengthening in elderly speakers. The research designed to observe dynamic speech production more directly will be needed.

• Journal of The Korean Society of Integrative Medicine
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• v.3 no.4
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• pp.43-51
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• 2015

Purpose : This study examines the effect of trunk stabilization program on the body balance, lung capacity, and muscular activity of the rectus abdominis and external oblique of healthy adults. Method : A survey was conducted for 20 students of K University located in the city of Y in Gyeongsangbuk-do Province of Korea. The trunk stabilization program consisted of a hollowing exercise, curl-up, bridging exercise, and birddog exercise. This was performed 14 times in total (7 times a week for two weeks). For analysis, good balance was used to measure both static and dynamic balancing ability. A peak flow meter was used to measure the maximum expiratory flow, and MP150 was used to measure muscular activity of the rectus abdominis and external oblique. Result : After the trunk stabilization program, the participants showed a difference in score and time taken to achieve static and dynamic balance, and muscular activity of the rectus abdominis and external oblique at a statistically significant level (p<0.05). However, no significant difference was observed in the left-to-right distance and front-to-back distance in a dynamic balance, and the lung capacity (p>0.05). Conclusion : The results showed that the trunk stabilization program was effective in enhancing both static and dynamic balancing ability and muscular activity. It also increased the lung capacity although the change was not at a statistically significant level.

• Physical Therapy Korea
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• v.24 no.1
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• pp.86-96
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• 2017

Background: Scapular dyskinesis is characterized by altered scapular position and motion. Specifically, excess activation of the Upper trapezius (UT) combined with decreased Lower trapezius (LT) and Serratus anterior (SA) have been observed. The Standard push-up plus exercise (SPP) is considered as a therapeutic exercise for increasing SA activity and maintaining the scapular kinematics. In addition, Using the Sling surface can lead to higher muscle activity. However, the advantage of an unstable surface has been uncertatin. Objects: To compare the activation of the UT, LT, and lower serratus anterior (LSA) muscles during various push-up plus exercises with and without sling in subjects with scapular dyskinesis. Methods: Total 18 male subjects with scapular dyskinesis were recruited. The UT, LT, and LSA electromyographic activities and the UT/LSA and UT/LT EMG activity ratios were measured during three push-up plus exercises with and without sling. Two-way repeated of analysis of variance was used to determine the statistical significance. Results: The UT activity was significantly lower in all postures without sling than that with sling. In addition, the LSA activity was significantly greater without than with sling, and significantly large in SPP, Low back supported push-up plus (LSPP), and Quadruped push-up plus. Additionally, the UT/LSA and UT/LT activity ratios were lower in SPP and LSPP without sling than with the other four push-up plus exercises. Conclusion: The push-up plus without sling were considered to decrease UT and increase LSA activity compared with exercises with sling. Furthermore, SPP without sling seems to be a more effective exercise for increasing LSA activity and lowering the UT/LSA and UT/LT activity ratios in scapular dyskinesis subjects.

• Safety and Health at Work
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• v.6 no.1
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• pp.56-61
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• 2015

Frozen food processing workers work under a cold environment which can cause several adverse health effects.This study explored factors affecting workers' health in the frozen food industry in Thailand. Participants comprised 497 workers exposed to a cold working environment and 255 office workers who served as the controls. Data were collected by a survey on the work environment, and the interview of workers for abnormal symptoms. The exposed group had the following characteristics: 52.7% male, overall average age of 27 (SD 6.6) years old, attained elementary education (Grade 4 and Grade 6) (54.1%), married (48.9%), smokers (21.3%), alcohol consumption (31.0%), duration of work was between 1 and 5 years (65.2%), working 6 days a week (82.7%), 1-5 hours of overtime per week (33.8%), office workers (33.9%); work category: sizing (6.9%), peeling (28.3%) dissecting (22.2%), and in the warehouse (8.6%). The temperature in the work environment ranged from $17.2^{\circ}C$ to $19.2^{\circ}C$ in most sections, $-18.0^{\circ}C$ in the warehouse, and $25^{\circ}C$ in the office areas. Warehouse workers had more abnormal symptoms than controls including repeated pain in the musculoskeletal system (OR 11.9; 95% CI 6.12-23.45), disturbance throughout the body (OR 4.60; 95% CI 2.00-10.56), respiratory symptoms (OR 9.73; 95% CI 3.53-26.80), episodic finger symptoms (OR 13.51; 95% CI 5.17-35.33). The study results suggest that workers' health should be monitored especially with regard to back and muscle pain, respiratory symptoms, episodic finger symptoms, and cardiovascular symptoms. Health promotion campaigns such as antismoking and reduction of alcohol consumption should be established because smoking and alcohol consumption are contributing factors to the pathogenesis of Raynaud's phenomenon and peripheral vascular disorders such as hypertension and heart disease.

• The Korean Journal of Pain
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• v.24 no.4
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• pp.205-215
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• 2011

Background: Interventional pain management (IPM) is a branch of medical science that deals with management of painful medical conditions using specially equipped X-ray machines and anatomical landmarks. Interventional physiatry is a branch of physical medicine and rehabilitation that treats painful conditions through intervention in peripheral joints, the spine, and soft tissues. Methods: A cross-sectional study was conducted using three years of hospital records (2006 to 2008) from the Physical Medicine and Rehabilitation Department at Chittagong Medical College Hospital in Bangladesh, with a view toward highlighting current interventional pain practice in a tertiary medical college hospital. Result: The maximum amount of intervention was done in degenerative peripheral joint disorders (600, 46.0%), followed by inflammatory joint diseases (300, 23.0%), soft tissue rheumatism (300, 23.0%), and radicular or referred lower back conditions (100, 8.0%). Of the peripheral joints, the knee was the most common site of intervention. Motor stimulation-guided intralesional injection of methylprednisolone into the piriformis muscle was given in 10 cases of piriformis syndrome refractory to both oral medications and therapeutic exercises. Soft tissue rheumatism of unknown etiology was most common in the form of adhesive capsulitis (90, 64.3%), and is discussed separately. Epidural steroid injection was practiced for various causes of lumbar radiculopathy, with the exception of infective discitis. Conclusion: All procedures were performed using anatomical landmarks, as there were no facilities for the C-arm/diagnostic ultrasound required for accurate and safe intervention. A dedicated IPM setup should be a requirement in all PMR departments, to provide better pain management and to reduce the burden on other specialties.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.108-114
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• 2018

One of the most performed action in daily life is standing up from sitting position. As the population of the world is aging at the high rates, people may face problems with reduced muscle strength as well as psychological changes. This can lead elderly people having difficulties with standing up from chair. Now, with the aging trend worldwide, products are being developed that can support the lives of the elderly. This study examines the distribution of hip pressure in relation to the seating positions of the standing assistance seats under development to prevent standing up accidents in older adults. The currently developing standing assistant chair designed to tilt to a maximum angle of 25 degrees. At over $25^{\circ}$, design considers that older people are at risk of thrown back out of that force and that the forces exerted on their arms and legs can be a significant burden to older people. By considering danger of higher than $25^{\circ}$ for older people which is experimented in the basis of static capturing approach in previous papers, it is experimented people with age group of 20~60 on $0^{\circ}$ to $25^{\circ}$ tilting angle on the basis of dynamic capturing method in order to pick convenient angle of inclination. Moreover, tried to find the optimum angle by comparing the hip pressure distribution when seated at the edge of the seat and at the center of the seat with the pressure distribution sensor.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.597-603
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• 2011

Objective: The objective of this study was to compare one-hand and two-hands lifting activity in terms of biomechanical stress for the range of lifting heights from 10cm above floor level to knuckle height. Background: Even though two-hands lifting activity of manual materials handling tasks are prevalent at the industrial site, many manual materials handling tasks which require the worker to perform one-hand lifting are also very common at the industrial site and forestry and farming. Method: Eight male subjects were asked to perform lifting tasks using both a one-handed as well as a two-handed lifting technique. Trunk muscle electromyographic activity was recorded while the subjects performed the lifting tasks. This information was used as input to an EMG-assisted free-dynamic biomechanical model that predicted spinal loading in three dimensions. Results: It was shown that for the left-hand lifting tasks, the values of moment, lateral shear force, A-P shear force, and compressive force were increased by the average 43%, as the workload was increased twice from 7.5kg to 15.0kg. For the right-hand lifting task, these were increased by the average 34%. For the two-hands lifting tasks, these were increased by the average 25%. The lateral shear forces at L5/S1 of one-hand lifting tasks, notwithstanding the half of the workload of two-hands lifting tasks, were very high in the 300~317% of the one of two-hands lifting tasks. The moments at L5/S1 of one-hand lifting tasks were 126~166% of the one of two-hands lifting tasks. Conclusion: It is concluded that the effect of workload for one-hand lifting is greater than two-hands lifting. It can also be concluded that asymmetrical effect of one-hand lifting is much greater than workload effect. Application: The results of this study can be used to provide guidelines of recommended safe weights for tasks involved in one-hand lifting activity.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.4
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• pp.227-239
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• 2011

Objectives: This study was performed to report the case of oriental medical treatment for the left lower limb monoplegia after herniated intervertebral disc(HIVD) operation at lumbar(L)-spine. Methods: A 38-year-old man who underwent lumbar HIVD operation at a hospital admitted with motor weakness of left lower limb, a little decreased left leg radiation pain and low back pain. We treated him by acupuncture, herbal medicine, bee venom injection moxibustion, cupping treatment physical therapy and measured with visual analogue scale(VAS), Oswestry disability index(ODI), Roland-Morris disability questionnaire(RMDO) and manual muscle test(MMT) from 8th February to 4th May 2011. Results: After treatment most symptoms decreased, VAS score changed from 10 to 3, ODI changed 71% to 37% RMDQ changed 13 to 8 and MMT changed from 3 to 5. Conclusions: Our study suggested that oriental medical treatments are significantly applicable to the monoplegia and pain after lumbar HIVD operation. And further studies ire required to identify underlying mechanism of the treatment.