• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.95-103
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• 2006

The purpose of this study was to analyze a change of maximal grip forces and EMG of agonists in upper extremity of 8 professional Ssirum players according to Satbar-grip patterns, to elucidate prime agonist muscles, contribution rate of each muscle, and a difference on EMG in upper extremity. one-way ANOVA(RM) performed for average and maximal values of each player after standardization and statistical significance was set as p<.05. The result includes the following: the highest grip force was A type with a statistic significance using one-way ANOVA and Duncan's comparison between A and C type. In summary the highest grip force was exerted on extension in the wrist than flexion in all grip types. Average and maximal values of biceps brachii and brachioradialis muscles were statistically significant and ones of flexor carpi ulnaris and extensor capi ulnaris were not.

• The Journal of the Korean dental association
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• v.56 no.6
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• pp.324-332
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• 2018

A mouthguard is a protective device normally worn on the upper jaw, to reduce injures to the teeth, jaws and surrounding soft tissues. It has a definite role in preventing injuries to the teeth and face and for this reason it is strongly recommended for all sporting activities where there is a risk of trauma to the teeth and associated structures. Mouthguards can be effective in reducing impact force to the teeth, and attributed to enhancement of postural control and muscle performance during teeth clenching. Although there is evidence that mouthguards reducing impact force to the teeth, and prevent orofacial trauma occurrence during sport practice, the influence of this device on athletic performance has not been systematically quantified. Nevertheless, wearing a dentally fitted laminated mouthguard of at least 3 mm thickness can be strongly recommended during sport practice.

• Korean Journal of Applied Biomechanics
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• v.28 no.4
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• pp.237-244
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• 2018

Objective: Flat-footed people struggle with excessive ankle joint motion during walking and running. This study aimed to investigate the effects of customized three-dimensional 3D-printed insoles on the kinematics of flat-footed people during daily activities (walking and running). Method: Fifteen subjects (height, $169.20{\pm}2.61cm$; age, $22.87{\pm}8.48years$; navicular bone height, $13.2{\pm}1.00mm$) diagnosed with flat feet in a physical examination participated in this study. Results: The customized 3D-printed insoles did not significantly affect 3D ankle joint angles under walking and running conditions. However, they shifted the trajectory of the center of pressure (COP) laterally during fast walking, which enhanced the load distribution on the foot during the stance phase. Conclusion: The customized 3D-printed insoles somewhat positively affected the pressure distribution of flat-footed people by changing the COP trajectory. Further research including comparisons with customized commercial insoles is needed.

• Advances in nano research
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• v.13 no.3
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• pp.217-231
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• 2022

This study investigates the geometrical impact on the nanomedicine drug delivery via nanodevices. A nanomotor made of the nanotube carrying the drug as the motor blade is considered in the blood flow. Physical activities change the blood flow, and sports training enhances the blood flow and plays a significant role in the stability of drug delivery devices. This paper studies the impact of geometrical parameters on the nanomotors carrying the nanomedicine. The effect of physical exercise on the dynamic response regarding the stability of drug delivery devices is discussed in detail.

• Journal of Sport and Applied Science
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• v.6 no.4
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• pp.11-23
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• 2022

New insights into the aetiology of anaemia in athletes have been discovered in recent years. From hemodilution and redistribution, which are thought to commit to so-called "sports anaemia," to iron deficiency triggered by higher requirements, dietary requirements, decreased uptake, enhanced losses, hemolysis, and sequester, to genetic factors of different types of anaemia (some related to sport), anaemia in athletes necessitates a careful and multisystem methodology. Dietary factors that hinder iron absorption and enhance iron bioavailability (e.g., phytate, polyphenols) should be considered. Celiac disease, which is more common in female athletes, may be the consequence of an iron deficiency anaemia that is unidentified. Sweating, hematuria, gastrointestinal bleeding, inflammation, and intravascular and extravascular hemolysis are all ways iron is lost during strength training. In training, evaluating the iron status, particularly in athletes at risk of iron deficiency, may work on improving iron balance and possibly effectiveness. Iron status is influenced by a healthy gut microbiome. To eliminate hemolysis, athletes at risk of iron deficiency should engage in non-weight-bearing, low-intensity sporting activities.

• Journal of Korean Orthopaedic Sports Medicine
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• v.11 no.1
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• pp.8-16
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• 2012

With the increase of participation in the sport activities, there has been a commensurate rise in the number of sport injuries. A more commonly encountered injured region in the upper-extremity is the wrist. Sport injuries are often characterized as overuse and traumatic. Traumatic injuries include fractures, dislocations, and ligament tears often seen in contact or collision sports. Overuse injuries, represented damages by a level of repetitive microtrauma sufficient to overwhelm the tissues$^{\circ}{\O}$ ability to adapt, include inflammatory conditions such as De Quervain$^{\circ}{\O}s$ disease, extensor carpi ulnaris tendinitis, intersection syndrome. Also included is a traumatic problem such as stress fractures of the hook of the hamate, subluxation of the extensor carpi ulnaris tendon, chronic scapholunate instabilities, and degenerative triangular fibrocartilage tears. This review will focus on both overuse and traumatic injuries of the wrist in the athletes. A significant emphasis will be placed on the evaluation, pearls and pitfalls of conservative and operative treatments.

• Journal of Obesity & Metabolic Syndrome
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• v.26 no.1
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• pp.52-60
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• 2017

Background: This study investigated the relationship between depressive symptoms and physical fitness, obesity indices, and vitamin D status in office workers. Methods: The subjects were 514 adults with more 30 years of experience as office workers in the city of Seoul. Lifestyle risk factors, obesity indices, physical fitness, and serum vitamin D levels were assessed with a standardized protocol. The Beck Depression Inventory (BDI) was used to assess depression status. Vitamin D status was assessed by measuring serum 25-hydroxyvitamin D concentrations. Based on the BDI scores, participants were classified into no depression (ND, $BDI{\leq}9$), mild depression (MiD, $10{\leq}BDI{\leq}15$), and moderate depression (MoD, $16{\leq}BDI{\leq}23$) groups. Results: Compared with the high cardiorespriatory fitness group, the low cardiorespiratory fitness (men OR=2.618, women OR=1.596) an middle cardiorespiratory fitness group (men OR=1.256, women OR=1.110) had significantly higher odds ratio for having depressive symptoms, even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, body mass index (BMI), percent body fat (%BF), and waist circumference (WC). Compared with the insufficient or deficient vitamin D group , the sufficient vitamin D group had significantly lower odds ratios for having depressive symptoms (men OR=0.121, women OR=0.114), even after adjustment for age, hypertension, diabetes, hyperlipidemia, cardiovascular disease, alcohol intake, smoking, BMI, %BF, and WC. Conclusion: Vitamin D supplementation and outdoor activities should be key components of a lifestyle intervention against office workers' depression.

• Korean Journal of Applied Biomechanics
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• v.25 no.4
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• pp.441-451
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• 2015

Objective : The purpose of the study was to investigate and compare the differences between Parkinson's disease rating, balance, fall and gait scales. Results : Parkinson's disease rating scales include the Hoehn-Yahr Scale and the Unified Parkinson's Disease Rating Scale (UPDRS). The Hoehn-Yahr Scale can measure disease rates easily; however it is not sensitive enough to evaluate the disease's process and management. UPDRS's advantage is in it's higher inter-reliability score; however it is more complicated to use. Parkinson's balance scales are comprised of the Berg Balance Scale (BBS) and the Activities-Specific Balance Confidence Scale (ABC). BBS has the advantage in that it is cheaper to measure and simple in use. ABC's advantage is especially in it's ability to measure higher functional levels; however it is more difficult measure responses due to scores appearing in both extremes. The Fall Efficacy Scale (FES) and The Survey of Activities and Fear of Falling in the Elderly (SAFE) are Parkinson's fall scales. FES's leverage over SAFE is that it is simpler to measure; however it does not coincide with responses which proves disadvantageous in measuring balance loss in high-level Parkinson's patients. SAFE's advantage is in it's simpler use and ability to be utilized without encountering the fear of fall; however it's at a disadvantage in regards to its use with multilateral aspects providing insufficient inspection. Lastly, the Dynamic Gait Index (DGI) and the Functional Gait Assessment (FGA) are Parkinson's gait scales. DGI is advantageous in its ability to test gait ability when exposed to a variety of external environments; however it is disadvantageous in that it registers higher scores with activities. FGA's advantage is in it's dynamic balance test; however it at a disadvantage with those unable to walk. Conclusion : A researcher of Parkinson's patients must choose each scale while considering their positive and negative characteristics.

• Korean Journal of Applied Biomechanics
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• v.16 no.3
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• pp.117-124
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• 2006

The modern convenient life formed by industrial development becomes lack of exercise and takes an interest in diet. Specially, professional walking shoes is developed as people take an interest in jogging, Those shoes, professional walking shoes or Dietshoes, increase exercise effects by change of heel types. Therefore, this study investigated motility effects by EMG experiment in order to measure Muscle Activities (MA) while wearing diet shoes (backless). Experiment was conducted by EMG measurement, from calf (gastrocnemius muscle), thigh (vastus muscle) and waist (erector spinae muscle), of 12 high school students. Exercise effects between the two shoes were analyzed by EMG (MF; Median Frequency, MPF; Mean Power Frequency, ZCR; Zero Crossing Rate). Results showed that the Dietshoes(MF: 48.21Hz, MPF: 65.0Hz, ZCR: 100.6Hz) had larger EMG value than that of Normal shoes(MF: 40.47Hz, MPF: 58.04Hz, ZCR: 82.09Hz). Also, in MA, the highest activities are showed in the calf, the second one is in waist, and last one is in thigh during gate. ANOVA between shoes in measurement parts showed significant effects in MF (gastrocnemius: p-value=.022, vastus laterals: p-value=.037, erector spinae: p-value=.082), MPF (gastrocnemius: p-value=.032, vastus laterals: p-value=.046, erector spinae: p-value=.090), and ZCR (gastrocnemius: p-value=.000, vastus laterals: p-value=.004, erector spinae: p-value=.134). And MA of Dietshoes is higher than that of Normal shoes, and decreasing rate of MA in Dietshoes is less than that of Normal shoes. Thus, this study validates exercise effects of Dietshoes.

• Korean Journal of Applied Biomechanics
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• v.25 no.3
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• pp.353-361
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• 2015

Objective : The aim of this study was to develop the non-powered horse riding device and was to evaluate the elaborate its applicability throughout static structural and transient structural analysis of the outdoor core strength exercise equipment. Method : Fifteen college students (mass: $69.55{\pm}13.38kg$, height: $1.69{\pm}5.61m$, age: $21.42{\pm}1.83yrs$) rode the powered horse riding device and 14 college students (mass: $71.12{\pm}9.74kg$, height: $1.73{\pm}3.31m$, age: $22.50{\pm}1.47yrs$) rode the non-powered horse riding device for the comparison. All motion capture data was collected at 100 Hz using six infrared cameras and the muscular activities were collected using a Delsys Trigno wireless system. The peak forward/backward lean angle, range of motion anter/posterior and vertical COM(Center of mass) movement of trunk and pelvis segment, and muscle activities of six muscles were compared between the two devices by using independent t-test (p<.05). Results : Several kinematic variables (peak forward-backward lean angle and vertical COM movement of trunk and pelvis segment, range of motion of trunk) significantly different between non-powered and powered horse riding device. The muscle activities of Rectus abdominis and External oblique of abdomen on the non-powered horse riding device were significantly greater than those of the powered device. Conclusion : It was concluded that non-power horse riding device could give the effect of core strength exercise as well as the body motion which can simulate the powered horse riding device.