• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.43-50
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• 2014

The purpose of this study was to analyze of the GRF (ground reaction force) parameters according to the change of positions and weights of bag during downward stairs between dominant and non-dominant in upper & lower limbs. To perform this study, participants were selected 9 healthy women (age: $21.40{\pm}0.94yrs$, height: $166.50{\pm}2.68cm$, body mass: $57.00{\pm}3.61kg$, BMI: $20.53{\pm}1.03kg/m^2$), divided into 2 carrying bag positions (dominant arm/R, non-dominant arm/L) and walked with 3 type of bag weights (0, 3, 5 kg) respectively. One force-plate was used to collect GRF (AMTI OR6-7) data at a sample rate of 1000 Hz. The variables analyzed were consisted of the medial-lateral GRF (Fx), anterior-posterior GRF (Fy), vertical GRF (Fz), impact loading rate and center of pressure (COPx, COPy, COP area, COPy posterior peak time) during downward stairs. 1) The Fx, Fy, Fz, COPx, and COP area of GRF were not statistically significant between dominant leg and non-dominant leg, but non-dominant leg, that is, showed the higher COPy, and showed higher impact loading rate than that dominant leg during downward stairs. 2) In bag wearing to non-dominant arm, Fx, Fz, COPx, COPy, impact loading rate and COP area showed increase tendency according to increase of bag weights. Also, against bag wearing to dominant arm, non-dominant showed different mechanism according to increase of bag weights. The Ground Reaction Force parameters showed different characteristics according to the positions and weights of bag during downward stairs between dominant and non-dominant arm.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.3
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• pp.126-132
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• 2012

Recently, pedestrian protection related research topics have been actively studied by automotive designers and engineers due to the enhanced pedestrian protecting regulations. It is required to design an energy absorbing structure, such as crumple zone that can sufficiently absorb the impact energy to reduce the leg injury when accident happens. The structure is designed by reducing the height of front end module, considering the mounting location, and investigating impact characteristics. In this paper, the concept of the crumple zone was introduced and the role of the crumple zone was investigated by analyzing the performance of upper legform impact to a bonnet leading edge test, and the design process was suggested.

• Journal of The Korean Society of Integrative Medicine
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• v.4 no.2
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• pp.29-36
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• 2016

Purpose : The purpose of this study was to find out the effects on muscle activations of serratus anterior and upper trapezius muscles when push-up plus exercise togu applied differently depending on the body part. Method : Thirty six volunteers took part in this study and we divided into three groups(upper arm togu group 12, leg togu group 12, upper arm-leg togu group 12). Each experimental group performed push-up plus exercise. All volunteers received a total of 18 exercise session over a 6 week period (three times per week). Exercise program was composed of serratus anterior and upper trapezius push-up plus exercise. Then we measured muscle activation of scapular stabilizer by electromyography. Repeated ANOVA was used to examine the effects of the intervention on each outcome measure. Result : After the six week intervention, there was a significant difference between the pre and 6 week in serratus anterior and upper trapezius muscle activity(p<0.05). After the six week intervention, there was a significant difference among the three group in serratus anterior muscle activity but no significant difference in upper trapezius muscle activity(p>.05). Conclusion : Serratus anterior and upper trapezius showed high muscle activity during push-up plus exercise. Therefore have a positive impact of scapular stabilizer. The larger the area of the unstable support surface, the larger muscle activity was larger of variation quantity.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.438-443
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• 2004

Court sport shoes is consisted of several functional parts such as soles, upper and midfoot reinforcements. Currently, intensive research for court sport shoes considering functional parts is in progress world widely, but the shoes design relies only on the view point of kinesilogy and biomechanics until now. Thus, more scientific and reliable evaluation of shoes characteristics is definitely required. In this paper, we evaluate the landing impact of court sport shoes by using finite element method. We construct a shoes-leg coupled FEM model which can simulate effectively impact in running mode. From the numerical analysis results, the designer can establish the advanced design concepts and build up the detailed design standard for the specific court sport shoes under consideration.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.133-134
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• 2007

• Sleep Medicine and Psychophysiology
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• v.24 no.1
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• pp.5-11
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• 2017

The use of alcohol is associated with the development and worsening of sleep disorder. Alcohol is generally known to have a sedative effect, but it has an arousal or sedative effect depending on the timing and drinking dose and directly affects REM sleep physiology. Alcohol acts on the central nervous system (CNS) to interfere with the sleep-wake cycle and to affect sleep-related hormone secretion. In addition, the ingestion of alcohol pre-sleep is associated with deterioration and development of sleep related breathing disorders (SBD). The increase in resistance of the upper respiratory tract and the decrease in sensitivity of the CNS respiratory center and the respiratory muscles are major mechanisms of alcohol-induced SBD, and result in snoring or apnea in healthy men or aggravating apnea in patients with OSA. Sleep-related restless leg syndrome and circadian rhythm disorders are common in alcohol use disorder patients. This review provides an assessment of scientific studies that investigated on the impact of alcohol ingestion on nocturnal sleep physiology and sleep disorders.

• International Journal of Automotive Technology
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• v.7 no.6
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• pp.715-720
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• 2006

This research investigates injury values and vehicle deformation for vehicle frontal crash compatibility. To investigate compatibility in an individual case, it is possible to impact two vehicles and evaluate the injury values and deformations in both vehicles. In this study, four tests were conducted to evaluate compatibility. A large and mini vehicle were subjected to a frontal car-to-car crash test at a speed of 48.3 km/h with an offset of 40%. An inclination car-to-car crash test using the large and small vehicle were conducted at 30 km/h at a $30^{\circ}$ angle. The results of the 48.3 km/h, car-to-car frontal crash revealed extremely high injury values on the chest and upper leg of the Hybrid III 50% driver dummy with seatbelt in the mini vehicle compared to the large vehicle. For the 30 km/h, car-to-car inclination crash, however, injury values in the small vehicle were 1.5 times higher compared to the large vehicle.

• Korean Journal of Applied Biomechanics
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• v.18 no.3
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• pp.11-21
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• 2008

The purpose of this study was to investigate the most optimum way of performing the bandal chagi during Taekwondo Kyorugi competition. By analyzing the EMG data and the kinematic data it was hoped that scientific data would be provided to instructors and players about the optimization of the Bandal Chagi. The results of the analysis are as follows: During competition while performing the Bandal Chagi the most important factors that affect the impact point are the range of motions of the upper body hyper extension and knee joints. Through the measurement of the muscles EMG activity of a well performed Bandal Chagi with the right leg it was observed that the left side erector spinae muscle was highly activated and so it was concluded that this muscle should be trained to improve the performance of the Bandal Chagi. Likewise it was observed that for the right side of the abdominal muscle's EMG there was a high activity level and thus showed that there was a large contribution of this muscle for the optimum performance of the Bandal Chagi.