• Korean Journal of Applied Biomechanics
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• v.22 no.2
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• pp.201-208
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• 2012

The purpose of this study was to investigate the effect of leg extension exercises performed on outdoor resistance exercise machines on knee extension muscle strength and quadriceps muscle group cross sectional area (CSA) in elderly women. Two groups were recruited for this study, including an exercise group (EG: n=13, $71.38{\pm}2.79$ yrs) and a control group (CG: n=5, $73.4{\pm}5.94$), In all subjects, maximum isometric and isokinetic muscle strength of knee flexion and extension were measured using an isokinetic dynamometer (Cybex(R) Humac Norm Testing & Rehabilitation System, USA). Quadriceps muscle group CSA were measured using MRI (Philps, Intera 1.5 T, NE Netherlands). The results of this study showed that post-intervention isometric knee extension peak torque value were higher than pre-intervention measures in the EG. However, the EG did not show improvement in quadriceps muscle group CSA, Also, no differences in the shift of optimal knee joint angle were observed between pre and post-intervention exercise. Outdoor leg extension exercise showed small increases in muscle strength in comparison to other resistance training exercises. The results of this study suggest that because outdoor leg extension exercise machines lack a progressive loading mechanism, significant increases in muscle strength may not be obtained.

• Journal of Digital Convergence
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• v.15 no.7
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• pp.497-504
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• 2017

This research aims to examine the difference of perceived experiences and sub-cultural identity between the overseas Korean' generations through the participation in the Korean National Sports Festival(NSF). Data were 360 overseas Koreans from 14 countries who participated in the 2015 NSF. The results were as follows; First, there was a difference in perceived experiences between overseas Korean' generations. More specifically, 1st generation among overseas Koreans has more positive participation experiences and less negative participation experiences than other generations. Second, there was a difference in sub-cultural identity between overseas Korean' generations. Particularly, 1.5 generation has much closer Korean identity than other generations.

• Physical Therapy Korea
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• v.28 no.3
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• pp.186-193
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• 2021

Background: While the formal test has been used to provide a quantitative measurement of core stability, studies have reported inconsistent results regarding its test-retest and intraobserver reliabilities. Furthermore, the validity of the formal test has never been established. Objects: This study aimed to establish the concurrent validity and test-retest reliability of the formal test. Methods: Twenty-two young adults with and without core instability (23.1 ± 2.0 years) were recruited. Concurrent validity was determined by comparing the muscle thickness changes of the external oblique, internal oblique, and transverse abdominal muscle to changes in core stability pressure during the formal test using ultrasound (US) imaging and pressure biofeedback, respectively. For the test-retest reliability, muscle thickness and pressure changes were repeatedly measured approximately 24 hours apart. Electromyography (EMG) was used to monitor trunk muscle activity during the formal test. Results: The Pearson's correlation analysis showed an excellent correlation between transverse abdominal thickness and pressure biofeedback unit (PBU) pressure as well as internal oblique thickness and PBU pressure, ranging from r = 0.856-0.980, p < 0.05. The test-retest reliability was good, intraclass correlation coefficient (ICC1,2) = 0.876 for the core stability pressure measure and ICC1,2 = 0.939 to 0.989 for the abdominal muscle thickness measure. Conclusion: Our results provide clinical evidence that the formal test is valid and reliable, when concurrently incorporated into EMG and US measurements.

• Journal of Sport and Applied Science
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• v.7 no.1
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• pp.21-29
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• 2023

Purpose: This study was to investigate the effects of isometric exercise on muscle activity and body balance ability in asymmetrical walkers. Research design, data, and methodology: Twenty gait asymmetry people were divided to unilateral exercise group (UG, n=10) and bilateral exercise group (BG, n=10). UG were performed unilateral exercise for 60 minutes, three times a week, and 16 weeks, and BG were performed one side and then the other side alternately for 60 minutes, three times a week, and 16 weeks. Muscle activity and body balance ability were measured before, after 4 and 16 weeks isometric exercise. Moreover, SI (symmetry index; SI) was calculated from the measured value of SL (step length). Statistical analyses were conducted using one-way ANOVA and two-way ANOVA with repeated measures, a paired t-test, and multiple comparisons according to Scheffe. Results: In the muscle activity, ST decreased significantly in short step length(S-SL) and BG of LS compared to before isometric exercise(p<.05), and GCM decreased significantly in BG of S-SL(p<.05). As for body balance ability, the mSEBT-A difference between L-SL and S-SL was decreased significantly in UG(p<.05). And the respective total scores of L-SL and S-SL, mSEBT-PM and mSEBT-PL were increased significantly in BG(p<.05). Conclusions: As a result, in this study above, it was confirmed that isometric exercise improved muscle activity and body balance ability in asymmetrical walkers.

• Journal of Industrial Convergence
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• v.20 no.9
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• pp.119-129
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• 2022

The purpose of this study was to investigate the relationship between self-management, stress coping, and physical self-concept of health exercise participants. To this end, a total of 274 questionnaire results were obtained by visiting 12 fitness center in the metropolitan area that is running a health exercise program. This was analyzed through the SPSS program, and the following results were obtained. It showed a significant explanatory power in the relationship between self-management and stress coping of health exercise participants. In addition, it also showed significant explanatory power in the relationship between self-management and physical self-concept. Finally, it showed significant explanatory power in the relationship between stress coping and physical self-concept. Through this study, it was found that there was a significant causal relationship between self-management, stress coping, and physical self-concept of healthy exercise participants. In follow-up studies, an in-depth analysis of self-management is required through the causal relationship with environmental factors related to self-management.

• Structural Engineering and Mechanics
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• v.86 no.4
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• pp.487-501
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• 2023

Nanoparticles have lower size and larger specific surface area, good stability and less toxic and side effects. In recent years, with the development of nanotechnology, its application range has become wider and wider, especially in the field of biomedicine, which has received more and more attention. Bone defect repair materials with high strength, high elasticity and high tissue affinity can be prepared by nanotechnology. The purpose of this paper was to study how to analyze and study the composite materials for sports bone injury based on multifunctional nanomaterials, and described the electrospinning method. In this paper, nano-sized zirconia (ZrO₂) filled micro-sized hydroxyapatite (HAP) composites were prepared according to the mechanical properties of bone substitute materials in the process of human rehabilitation. Through material tensile and compression experiments, the performance parameters of ZrO₂/HAP composites with different mass fraction ratios were analyzed, the influence of filling ZrO₂ particles on the mechanical properties of HAP matrix materials was clarified, and the effect of ZrO₂ mass fraction on the mechanical properties of matrix materials was analyzed. From the analysis of the compressive elastic modulus, when the mass fraction of ZrO₂ was 15%, the compressive elastic modulus of the material was 1222 MPa, and when 45% was 1672 MPa. From the analysis of compression ratio stiffness, when the mass fraction of ZrO₂ was 15%, the compression ratio stiffness was 658.07 MPa·cm³/g, and when it was 45%, the compression ratio stiffness is 943.51MPa·cm³/g. It can be seen that by increasing the mass fraction of ZrO₂, the stiffness of the composite material can be effectively increased, and the ability of the material to resist deformation would be increased. Typically, the more stressed the bone substitute material, the greater the stiffness of the compression ratio. Different mass fractions of ZrO₂/HAP filling materials can be selected to meet the mechanical performance requirements of sports bone injury, and it can also provide a reference for the selection of bone substitute materials for different patients.

• Journal of Korean Orthopaedic Sports Medicine
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• v.8 no.2
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• pp.76-82
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• 2009

Purpose: The purpose of this study was to analyze the clinical result and the gait patterns for patients who had undergone the arthroscopic posterior cruciate ligament (PCL) reconstruction using Achilles allograft. Materials and Methods: Among the patient who had undergone the arthroscopic PCL reconstruction using fresh-frozen Achilles allograft between March 2004 to March 2005, we selected 12 patients who compliance to our rehabilitation program. Clinical result and gait analysis were carried out at 36 months postoperatively. There were measured by using range of motion (ROM), Lysholm knee score, Tegner activity score, IKDC score, posterior stress test, and posterior translation measured by using Telos stress arthrometer. Kinematic gait analysis was carried out using 3-dimensional gait analysis system. Results: The PCL reconstruction surgery yielded statistacally significant results in all of clinical evaluation. In gait analysis, the average knee flexion angle increased during stance phase and decreased during the swing phase, but was not statistically significant and there were no significant difference between both sides of their knees overall. Conclusion: Since there was no statistically significant difference between the injured and uninjured sides as a result of the gait evaluation of the patients who had arthroscopic reconstruction surgery on their PCL injured knee and conformed to the rehabilitation program, systemic and strict rehabilitation ought to be important in the reconstruction surgery.

• Journal of the Korea Convergence Society
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• v.12 no.4
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• pp.303-310
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• 2021

This study was conducted to identify the effects of pressure taping between tibia and fibula of High Ankle Sprain athletes on pain, Range of Motion(ROM), and strength and to provide basic data for rehabilitation programs. The subjects of the study were conducted with a total of 10 athletes except for four who gave up who were diagnosed with high ankle sprain, or who were diagnosed with ankle sprain but their physical examinations proved positive. The results showed no significant differences in pain(Visual Analog Scale, VAS). The ROM was significantly increased in inversion(IV) and eversion(EV) in both groups. The Isometric strength was significantly improved in IV(0°, 7°, 14°) and EV(0°) in Taping Group(TG). When taping was applied to athletes with injury to the High Ankle Sprain, ROM and muscle strength improved at the same pain level.

• Journal of Korean Orthopaedic Sports Medicine
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• v.2 no.1
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• pp.37-43
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• 2003

Purpose: This study is to analyse the injury patterns of knee ligament and the factors influencing ligament injuries of knee, and to evaluate the changes of knee function and activity after ski injury. Materials and Methods: Thirty cases of ligament injuries of knee were studied with a questionaire, stress radiographs, magnetic resolution imaging, and physical examination. Mean age was 28.6 years old and mean follow up was 29.6 months. Clinical evaluation of Lysholm knee scoring scale was used for knee function and Tegner activity score was used for activity change after ski injury. Results: The anterior cruciate ligament (ACL) injury accompanied with medial collateral ligament(MCL) injury was most in 11 cases and isolated MCL injury was the next in 9 cases. The common types of injury mechanism were Phantom foot phenomenon (13 cases, 43$\%$) and valgus external rotation injury (12 cases, 40$\%$), which constitute 83$\%$ of all case. At the last follow up, the mean Lysholm score was 93.4 and mean Tegner activity score was 4.2. The reduced Tegner activity score after injury was 1.9. Among several injury groups, the evaluation of knee function and activity was best in the isolated MCL injury group and worst in the ACL injury accompanied with MCL injury group. The factors to influence ski injury were participation to ski class, release of binding, and skiing long time more than 2 hours. Conclusions: Lysholm score at last follow up revealed good grading, but sports activity after ski injury was reduced when compared with pre-injury state. It seems to need a active, systemic sports rehabilitation program after sports injury.

• Convergence Security Journal
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• v.15 no.3_2
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• pp.77-82
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• 2015

IT convergence has been approached from national strategic dimension with an aim to drive forward technology development and industrial advancement in other fields by taking the IT to the next advanced level, and has been the focus of intensive investment of research resources. Against this backdrop, IT convergence has emerged as a cutting-edge convergence industry that helps spur development of new growth engine being pushed forward at inter-ministerial level, as well as help turn the mainstay industries into high value-added industries and create new IT industry. Health-related convergence services have shifted its focus towards the exercise/sports and rehabilitation-oriented entertainment experiential industry away from conventional disease prevention and control-centric treatment/therapy technology industry. Thus, this study was intended to examine the trends of IT convergence technological development related to health exercise and present recommendation on the future course for development of major technologies and advancement of convergence industry, given the importance assigned to IT convergence.