• Journal of The Korean Society of Integrative Medicine
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• v.3 no.2
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• pp.73-78
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• 2015

Purpose: This study was conducted to investigate out the effects of power by body application of weight training that can increase vertical jump, standing long jump, and medicine ball throw that are important factors for power ability. Methods: Sixteen in normal adult were participated in this study. The subjects were divided into the upper limb weight training group(N=16), the lower limb weight training group(N=16) and they exercised during a four-week period of time, three times a week, 70 minutes each, and the each group did take part in any exercise program. To evaluate the changes in power were measured by using the vertical jump, standing long jump, and medicine ball throw. The data was analyzed with a SPSS 18.0 program. Results: The results showed that the vertical jump, standing long jump were significantly increased in the upper limb weight training group(p<.01) and medicine ball throw was significantly increased in the both group(p<.05). However, there were that showed not significantly differences in all power items between two groups after experiment(p>.05). Conclusion: It was concluded that the weight training were effective in enhancing the power ability. Also, can be considered effective the better lower limb weight training group than upper limb weight training group.

• Physical Therapy Rehabilitation Science
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• v.10 no.2
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• pp.161-166
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• 2021

Objective: The purpose of this study was to quantitatively evaluate the Wii Balance Board (WBB)-based jump performance for the elderly and to confirm the difference in jump performance according to age. Design: Cross-sectional study. Methods: 40 young adults (aged 22.5±2.2 years) and 33 elderly (aged 75.1±5.2 years) without orthopedics disease participated in this study. Standing on the WBB then, with the signal "start," jump vertically to the maximum height at which you can jump, land on the force plate after jump and keep it standing on both feet. All subjects were required to practice the jump sufficiently before starting the measurement, each measuring three times, and the mean values were used. A one-minute break was provided between each trial. Evaluators waited within 1meter for every test to prepare for fall. Results: The vertical ground reaction force of elderly and young adults when jumping using WBB showed a significant difference (p<0.05) and demonstrated discriminant validity. Between two groups, there were significant differences in overall jump time (p<0.05), maximum value (p<0.05), minimum value (p<0.05), center of pressure (COP) pathlength (p<0.05), and flight time p<0.05). Conclusions: This study found that performing the vertical jump, the elderly showed longer jump time, lower vertical ground reaction force, COP pathlength and shorter flight phase than healthy young adults using WBB and demonstrated that as a measurement tool, WBB discriminated vertical jump performance between elderly and young adults.

• Korean Journal of Applied Biomechanics
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• v.27 no.2
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• pp.141-147
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• 2017

Objective: We obtained force-displacement curves for countermovement jumps of multiple heights and examined the effect of an arm swing on changes in vertical jumping strategy. Countermovement jumps with hands on hips (Condition 1) and with an arm swing (Condition 2) were evaluated to investigate the mechanical effect of the arm movement on standing vertical jumps. We hypothesized that the ground reaction force (GRF) and/or center of mass (CoM) motion resulting from the countermovement action would significantly change depending on the use of an arm swing. Method: Eight healthy young subjects jumped straight up to five different levels ranging from approximately 10% (~25 cm) to 35% (~55 cm) of their body heights. Each subject performed five sets of jumps to five randomly ordered vertical elevations in each condition. For comparison of the two jumping strategies, the characteristics of the boundary point on the force-displacement curve, corresponding to the vertical GRF and the CoM displacement at the end of the countermovement action, were investigated to understand the role of arm movement. Results: Based on the comparison between the two conditions (with and without an arm swing), the subjects were grouped into type A and type B depending on the change observed in the boundary point across the five different jump heights. For both types (type A and type B) of vertical jumps, the initial vertical force at the start of push-off significantly changed when the subjects employed arm movement. Conclusion: The findings may imply that the jumping strategy does change with the inclusion of an arm swing, predominantly to modulate the vertical force advantage (i.e., the difference between the vertical force at the start of push-off and the body weight).

• Journal of Korean Physical Therapy Science
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• v.29 no.1
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• pp.47-54
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• 2022

Background: Plyometric exercise is an exercise exerting forceful power in a brief period using isotonic activation. It is effective to improve reaction of muscle, agility, endurance and athletics performance. Weight training is an exericse improving muscular strength, endurance and respirating ability applying diversely in frequency and load of exercise Plyometric exercise and Weight training is to facilitate the athletics performance though improving the function of lower limb muscle, there is a difference that Plyometic jump squats is the way to improve agility and Weight training is the way to improve muscular strength. Therefore, it is necessary to know how this difference effects on athletics performance as measuring ankle, ROM, and jumping ability. Design: Randomized controlled trial. Method: This study was conducted with the voluntary participation of 40 university students, who were randomly assigned to jump squat and calf raise groups (n=20 per group). For each subject, we measured the range of motion of the ankle joint before and after exercise, as well as a standing broad jump and vertical jump test performance. We compared the performance indices before and after exercises using paired t-tests, and between groups using independent-samples t-tests. Conclusions: Both jump squat and calf raise exercises improved ankle joint dorsiflexion and plantar flexion, as well as standing broad jump and vertical jump height performance. However, there were no significant differences before versus after exercise, or between exercise types. Although jump squats and calf raises have different purposes, it is thought that, in combination, these exercises improve performance more effectively than either alone, and that such a combined exercise program improves the quality of training in both the general public and athletes in various sports.

• The Journal of Korean Physical Therapy
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• v.26 no.3
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• pp.147-155
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• 2014

Purpose: This study was to determine the effects of before and after application of silicone sleeve on balance and muscle strength in anterior cruciate ligament (ACL) reconstruction patients. Methods: 13 subjects who had one or more months after ACL surgery were involved. Dynamic balance, timed up and go (TUG), stair step, vertical jump, proprioception and isokinetic knee strength were measured while subjects under taped, untapped and silicone sleeve conditions. Results: For 30 seconds one-leg standing, there was a significant improvement under silicone sleeve on operated side with eyes open and both taping and silicone sleeve revealed similar effects with eyes closed (p<0.01). Application of silicone sleeve showed significant effects in proprioceptive function on the operated side compared to both taping and none (p<0.05). For stair step test, TUG and vertical jump was a tendency to improve after application of silicone sleeve, but no significant different. Muscle strength on operated side of quadriceps and hamstring was significantly improved compared with none or taping(p<0.05). Conclusion: Silicone sleeve application for ACL reconstruction patients was effective immediately on improving strength and balance. Therefore, depending on the intended use and the disease is considered appropriate use of silicone sleeve will be able to help prevention and functional movement.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.6
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• pp.617-624
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• 2011

The two-dimensional sloshing problem in a rigid rectangular tank with a free surface is considered. The flow is generated by a container in harmonic motion in time along the horizontal axis, i.e., a container excited by u=Asin($2{\pi}ft$) where u denotes the container velocity imposed externally, A is the amplitude of the oscillation velocity, and f is the frequency of oscillation. Experimental apparatus is arranged to investigate the large-amplitude sloshing flows in off-resonant conditions, where the large amplitude means that A~O(1), and the distance, S, is comparable to the breadth, L, of the container, i.e., L/S~O(1). Comprehensive particle image velocimetry (PIV) data are obtained, which show that the flow physics of the nonlinear off-resonant sloshing problem can be characterized into three peculiar free surface motions: standing-wave motions similar to those of linear sloshing, a run-up phenomenon along the vertical sidewall at the moment of turn-over of the container, and gradually propagating bore motion from the sidewall to the interior fluid region, like a hydraulic jump.

• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.527-534
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• 2022

The purpose of this study was to investigate the effects of 12 weeks of muscle power and agility training on physical fitness factors and isokinetic muscle function in elementary school male soccer players. For this purpose, 6 muscle power and agility training programs were organized for 12 elementary school male soccer players and were conducted 3 times a week for 12 weeks. The results of measurement and analysis of physical fitness factors before and after the muscle strength and agility training are as follows. First, there was a significant difference in the standing long jump in place of muscle power(p<.001). Second, there was a significant difference in the standing vertical jump of muscle power(p<.05). Third, there was a significant difference in the side step of agility(p<.01). As a result, 12 weeks of muscle power and agility training can be expected to have a positive effect on the improvement of agility and agility of elementary school male soccer players, and it is judged that it can provide training basic data for injury prevention and performance improvement.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.247-253
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• 2005

In this paper, I was undertaken to identify factorial structure of physical fitness components for male high school Taekwondo players. In order to accomplish this purpose, the selected 8 physical fitness test were conducted to 50 male high school Taekwondo players. For the concretely, this study was conducted to physical fitness battery was grip strength, vertical jump, standing trunk flexion, sit-ups, closed eyes foot balance, 10m shuttle run, 50m run, and 1600m run. Factor analysis was applied for analyzing factorial structure of each physical fitness components.

• Journal of the Korean Society of Clothing and Textiles
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• v.21 no.2
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• pp.286-291
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• 1997

The purpose of this study is to examine the effect of clothing habits wearing cool or warm in daily life on motor ability. A group of ten healthy young females were divided into a cold (C) group and a warm (W) group. From autumn to winter, C group was advised to wear cool clothing, and W group, warm Clothing. The subject's physical fitness were tested in October, initial stage of the clothing training and March of the following year, final stage of the training. The measurements were taken after the subjects rested in a thermoneutral room conditioned at 23$\pm$2$^{\circ}C$ over 1 hour. The test items were weight, skinfold thickness, grip strength (right, left), back-lift strength, vertical jump, sit-ups, Irosmax, side step test, single-foot standing test with eyes closed, and standing trunk flexion. Changes in motor ability of each group between initial stage and final stage of the training were compared. 1. Muscle strength, part of the motor revelation capacity, showed no significant change in the both ,Troops. On the other hand, strength and power showed a decrease in the both groups and C group showed a sharp decrease. 2. Muscular endurance and cardio-pulmonary fitness, part of the motor continuation capacity, were increased after the training and the degree of increase was great in C group. 3. C group showed significant increase in motor coordination capacity including agility, balance, and flexibility after the training, while Wgroup showed significant increases only in balance. 4. Weight and skinfold thickness as a part of the physique showed no significant change.

• Journal of the Korean Institute of Navigation
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• v.25 no.4
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• pp.347-360
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• 2001

The purpose of this study is to find out the subjective and objective fatigue level and the characteristics of seamen's physical strength with the service period on board, to have a new understanding of the vocation, and to explore a physical exercising program for the seamen. The questionnaire survey for the seamen who had been in service on the ocean going vessels was conducted and the results are fumed out as the followings. Total number of seamen who had answered the questionnaire was 64 persons and the distribution status of service period group was identified as 16 persons for each of 4 groups； the group was classified as the group of less than 5 years, 5 - 10 years, 10 - 15 years, and more than 15 years. 1. Working conditions Working hours in a week was identified as 44－56 hours(45.3%) and the number of 45.3% of the seamen answered the working hours in week is more than 56 hours. The seamen of 25.0% are unsatisfied or very unsatisfied with their vocation. The seamen of 65.6% are smoking, and 45.3% of them drink. The seamen of 44.,3% drink once or more in a week. And the seamen of 67.2% do not take any exercise in a week. 2. Contribution to the seamen's fatigue and subjective symptom The most contributive factor to the seamen's fatigue was identified as the short of sleeping(21.5%), overwork(19.2%), poor working conditions (18.6%), and the friction in human relations also becomes one the contribution to the fatigue(14.0%). The subjective symptom by fatigue was identified as the feeling of languid, sleepy and tiredness of eyes. 3. Characteristics of the seamen's physical strength and Interrelations The grip strength and back strength of the seamen whose service period is less than 5 years were measured as 40.44kg and 127.8kg. The sit ups in the group of service period less than 5 years was measured as 36.84 times, and the vertical jump for the seamen in this group was measured as 46.55cm. The closed-eyes foot balance was measured as 33.64 seconds in the group of service period between 5 and 10 years, and side-step was measured as 35.31 times in the group of service period less than 5 years. The standing trunk flexion was measured as 10.54cm for the seamen whose service period is between 10-15 years, and the trunk extension was measured as 50.70cm for the seamen whose service period is less than 5 years. And the step test of the seamen whose service period is between 10-15 years was measured as 54.44 numbers, and the number of flickers of the seamen whose service period is less than 5 years was measured as 32.94.