• Korean Journal of Applied Biomechanics
• /
• v.29 no.3
• /
• pp.167-172
• /
• 2019

Objective: The aim of this study was to investigate the effect of midsole hardness of running shoe on muscle fatigue and impact force during distance running. Method: Ten healthy college recreational runners who were performing distance running at least three times a week participated in this experiment. They were asked to run for 15 minutes in the treadmill at 10 km/h with running shoes having three different types of midsole hardness (Soft, Medium, Hard). EMG signal and insole pressure were collected during the first and last one minute for each running trials. Data were analyzed using a one-way analysis of variance (ANOVA) with repeated measures. Results: Midsole hardness did not affect the consistency of stride length. For the median frequency of the EMG signal, only VL was affected by midsole hardness; that of medium was greater than other midsoles (p<.05). The loading rate of impact forces increased by midsole hardness (p<.01). Conclusion: Although soft midsole could attenuate impact forces at heel contact, it might have a negative effect on the fatigue of muscle which could decelerate the body after heel contact. Therefore, it is necessary to select the optimum hardness of midsole carefully for both reduction impact forces and muscle fatigue.

• Journal of Korean Ophthalmic Optics Society
• /
• v.9 no.2
• /
• pp.233-239
• /
• 2004

This study investigated the status of soft contact lens wear in college students. The results were as follows: 1. The most prevalent age of initial contact lens wear was 19 years or 20 years, with an age distribution in females from as early as 10 years to 20 years. 2. For almost all subjects, the test clinic for the contact lens wear assessment and purchase of the contact lenses was an optical shop. 3. The main advantage for most male subjects was use for sports, whereas most female subjects used contact lenses for cosmetic reasons. 4. The most common side-effects experienced due to contact lens wear were red eye, foreign body sensation, and eye pain. 5. The most frequently reported eye disease caused by contact lens wear was conjunctivitis, with only few subjects experiencing keratitis. 6. Following treatment for the side effects of contact lens wear, most subjects hoped to re-use the previous contact lenses, some subjects wanted to change to new contact lenses, and others subjects refused further contact lens wear.

• International journal of advanced smart convergence
• /
• v.11 no.3
• /
• pp.179-186
• /
• 2022

In this paper, we design a heart rate measurement system using a web camera. In order to measure the heart rate, face image information is acquired and classified. The face image data is collected from web camera. The heart rate is measured using the collected face image data. We design a function to measure heart rate using input of face information using a web camera in non-contact manner. We design a function that reads face information and estimates heart rate by analyzing face color. An experiment was performed to compare the non-contact heart rate with the actual measured heart rate. The heart rate measurement system using a web camera proposed in this paper is a technology that can be used in various fields. It will be used in sports fields that require heart rate measurement at a low cost.

• Korean Journal of Applied Biomechanics
• /
• v.15 no.1
• /
• pp.259-274
• /
• 2005

The purpose of this study was to compare the kinematic and kinetic parameters of lower extremity joints between novice and experienced sports aerobic dancers during two heights of depth jumps. Four male dancers were participated in this study and they performed 40cm and 60cm height depth jump three times, respectively. Four ProReflex MCU cameras (100frame/sec) and a Kistler force plate (1000Hz) were used for data collection. The results indicated that the duration of contact phase of experienced group was shorter than that of novice group regardless of jump height. For minimum angle of hip, knee, and ankle joints, the novice group had tendency to decrease the angle but the experienced group had increased the joint angle with jump height. There was no difference of total ground reaction force between the groups but the reaction force had tendency to increase with jump height. Thus, this study implied that repetition of jump and landing may induce joint related injury and further study such as. EMG analysis of lower extremity can be needed to verify the relationship between injury and ground reaction force.

• Korean Journal of Applied Biomechanics
• /
• v.33 no.3
• /
• pp.110-117
• /
• 2023

Objective: The purpose of this study was to find out kinematic and kinetic differences the lower extremity joint according to the landing type during vertical jump movement after jump landing, and to present an efficient landing method to reduce the incidence of injury in youth players. Method: Total of 24 Youth players under Korean Sport and Olympic Committee, who used either heel contact landing (HCG) or toe contact landing (TCG) participated in this study (HCG (12): CG height: 168.7 ± 9.7 cm, weight: 60.9 ± 11.6 kg, age: 14.1 ± 0.9 yrs., career: 4.3 ± 2.9 yrs., TCG height: 174.8 ± 4.9 cm, weight: 66.9 ± 9.9 kg, age 13.9 ± 0.8 yrs., career: 4.7 ± 2.0 yrs.). Participants were asked to perform jump landing consecutively followed by vertical jump. A 3-dimensional motion analysis with 19 infrared cameras and 2 force plates was performed in this study. To find out the significance between two landing styles independent t-test was performed and significance level was set at .05. Results: HCG showed a significantly higher dorsi flexion, extension and flexion angle at ankle, knee and hip joints, respectively compared with those of TCG (p<.05). Also, HCG revealed reduced RoM at ankle joint while it showed increased RoM at knee joint compared to TCG (p<.05). In addition, HGC showed greater peak force, a loading rate, and impulse than those of TCG (p<.05). Finally, greater planta flexion moment was revealed in TCG compared to HCG at ankle joint. For the knee joint HCG showed extension and flexion moment in E1 and E2, respectively, while TCG showed opposite results. Conclusion: Compared to toe contact landing, the heel contact landing is not expected to have an advantage in terms of absorbing and dispersing the impact of contact with the ground to the joint. If these movements continuously used, performance may deteriorate, including injuries, so it is believed that education on safe landing methods is needed for young athletes whose musculoskeletal growth is not fully mature.

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

• The Korean Journal of Pain
• /
• v.31 no.1
• /
• pp.54-57
• /
• 2018

Burner or stinger syndrome is a rare sports injury caused by direct or indirect trauma during high-speed or contact sports mainly in young athletes. It affects peripheral nerves, plexus trunks or spinal nerve roots, causing paralysis, paresthesia and pain. We report the case of a 57-year-old male athlete suffering from burner syndrome related to a lumbar nerve root. He presented with prolonged pain and partial paralysis of the right leg after a skewed landing during the long jump. He was initially misdiagnosed since the first magnet resonance imaging was normal whereas electromyography showed denervation. The insurance company refused to pay damage claims. Partial recovery was achieved by pain medication and physiotherapy. Burner syndrome is an injury of physically active individuals of any age and may appear in the cervical and lumbar area. MRI may be normal due to the lack of complete nerve transection, but electromyography typically shows pathologic results.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.22 no.3
• /
• pp.33-47
• /
• 2020

As people have gained leisure time and become more interested in sports, various industries catering to these sports, including aquatic and underwater activities are growing. Many people are getting into scuba diving, where people can explore the sea at depths of more than 40-meters. Despite the increasing demand, there are limited studies on the sport. This study aims to provide basic research on materials suitable for developing technical scuba diving suits by analyzing several areas, such as design, material, sewing patterns, etc. The following trends were observed in all wetsuits: closure designs, ergonomic patterns, practical and functional details. Neoprene was the primary material of diving suits, and various functional materials were attached to the outer fabric or lining. The seam technique which minimized water contact and improved durability was sewing. Various techniques were also applied, such as flatlock stitching, GBS, LFS, etc. Subsequent studies shall investigate consumer preference etc. and other aspects, and continue to allow for the research and development of technical diving suits.

• 재활복지
• /
• v.21 no.4
• /
• pp.59-75
• /
• 2017

The purpose of this study was to analyze sports injuries in athletes with disabilities during the 2015 National Games in Korea. We conducted a survey to assess sport injuries in 171 male athletes with disabilities who participated in this study. The shoulder was most frequently injured, followed by the fingers and low back. Contusions were the most common type of injury, and were usually caused by collisions with teammates or contact with equipment. Injuries often occur during enthusiastic play in both competition and practice sessions. Injured athletes are emergently treated with medicated spray and patch application by the head coach. Warm-up and cool-down exercises are recommended to prevent injury, and physical therapy is effective after an injury occurs. Based on these findings, an injury prevention training program and athletic trainers should be provided for athletes with disabilities to ensure appropriate care and rehabilitation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.20 no.4
• /
• pp.648-655
• /
• 2019

This paper proposes the differential development of a Taekwondo electronic body protector. For this development, the most suitable sensor system was selected after analyzing and testing various sensor methods (magnetic sensors, electric capacity sensors, contact switch sensors, and piezo-film sensors) that could be applied in the electronic body protector, the selected sensors were distributed to the body and feet to make a more precise hit score, unlike the existing system in which all sensors are centralized on the body. Furthermore, it aims to illuminate using a lightweight film-type piezoelectric sensor on the body protector. In the case of an existing electronic body protector, all sensors and network device were concentrated on the body protector, so users need to purchase a set if they want it. On the other hand, the proposed system cloud can be used individually using a smart scoring WEP program. The effects of decreasing weight by up to 20% were compared with those of the existing system. Setting up a test facility is very difficult, so more study will be needed to analyze the effects of a hit.