평창동계올림픽 알파인 스키 회전ㆍ대회전 코스의 지형 특성 및 경기력 요인에 미치는 영향

윤석훈 ( Yoon Sukhoon ),김진해 ( Jin-hae Kim ),박재현 ( Jae-hyeon Park ),류지선 ( Jiseon Ryu ),박상균 ( Sang-kyoon Park ),김주년 ( Kim Joo Nyeon ) 한국체육대학교 체육과학연구소 2019 스포츠사이언스 Vol.36 No.2

The aim of this study is to quantify the characteristics of Rainbow course of Yongpyong resort where the giant slalom (GS) and slalom (SL) of the PyeongChang Winter Olympic Games are held, and to investigate the correlation between the characteristics and the skier’s speed. A candidate for the national alpine ski team who are continuously training the giant slalom and slalom at rainbow course of the Yongpyong resort participated in the study. The Global Positioning System (GPS) was used to measure the position of the gates of GS and SL, and to collect the skier’s trajectory when skier was running. The collected latitude, longitude, and altitude data were chaged into meter units, and the gate distance, gate shift angle, and gradient were calculated and the correlation between the skier’s speed and course characteristic parameters was analysed. The gate distance was 28.60±5.26 m in GS and 12.79±2.53 m in SL. The gate shift angle was 139.68±13.42° in GS and 162.94±9.77°, in SL. The gradient was -28.54±13.65° in GS and -33.66±8.57° in SL. In addition, in the giant slalom and slalom, there was a significant correlation between gate distance and skier’s speed and between gradient and skier’s speed.

스포츠 마사지 견갑부 전문기법 적용이 Push up 시 근전도에 미치는 영향

윤우람 ( Yoon Wooram ),윤석훈 ( Yoon Sukhoon ) 한국체육대학교 체육과학연구소 2018 스포츠사이언스 Vol.35 No.2

The purpose of this study is the effects of the sports massage before having exercise, by analyzing how the professional sports massage shoulder technique influences on Agonist and Synergist during push-ups. It has studied 15 office workers using computer for a long time in a ”S” company, located in Songpagu, Seoul. The participants were composed of 10 men and 5 women (Age: 27.26+-2.12years, Height: 172.35+-8.91cm, Weight: 67.72+-13.23kg); they have had no experience on the injured shoulder and elbow joint recently and were able to exercise push-ups. The participants were informed beforehand how to exercise push-ups consistently. The activities were measured three times for 5 seconds in flexion and extension period excluding the start and end points of a second in isometric position and the results were averaged. The measure of the muscle activity had been repeated and compared with the value after 10 minutes professional sports massage shoulder technique and 5 minutes rest. The result of this study is that there is statistically a significant difference in muscle agonist activity of the pectoralis major at the bend section after sport massage, and also in the ratio of pectoralis major and upper and lower trapezius. therefore, the professional sports massage shoulder technique applied to reduce the tension of the upper trapezius, and the muscle activity of the pectoralis major, which is the agonist for push-ups, was increased by unstable shoulder movement mitigation.

기계체조 도마 동작의 도움닫기 구간이 경기력에 미치는 영향

윤창선 ( Yoon Changsun ),양태영 ( Yang Tae-young ),박상헌 ( Park Sangheon ),윤석훈 ( Yoon Sukhoon ) 한국체육대학교 체육과학연구소 2018 스포츠사이언스 Vol.36 No.1

The purpose of this study was to determine the effects approaching phase on vaulting in gymnastic performance. Ten gymnasts, divided into skilled group(age: 22.4±1.5 years, height: 165.2±2.9 cm, weight: 61.2±4.1 kg, career: 12.0±2.5 years) who performs vaulting skill level over than 5.2 points and less-skilled group(age: 21.6±0.5 years, height: 162.8±3.6 cm, weight: 57.4±3.2 kg, career: 10.0±2.1 years) who performs vaulting skill level less than 4.8 points, were participated in this study. Then, subjects were asked to perform the Lou Yun movement five times. The board contact, horse contact time, velocity and momentum of approaching phase were measured. In result, the board contact time in skilled group was significantly shorter than less-skilled group(p<.05). Moreover, the velocity and momentum of approaching phase in skilled group were greater than less-skilled group(p<.05). It indicates that skilled group performs more powerful contact than less-skilled group on the board. In addition, skilled group has a big potential for performing high level movements on vaulting with greater velocity and momentum compared with less-skilled group. Therefore, the training for running, approaching which could be step matching, and board contact are very important in order to enhance vaulting performance in gymnastics.

알파인 스키 레이싱 회전종목에서 오픈기문과 헤어핀 기문의 구간별 회전전략

김주년 ( Kim Joonyeon ),윤석훈 ( Yoon Sukhoon ) 한국체육대학교 체육과학연구소 2021 스포츠사이언스 Vol.39 No.1

The purpose of this study was to investigate the kinematic differences between the turning techniques of the hair-pin combination and of the open gate in the alpine ski slalom. Fourteen Korean alpine ski racers were participated in this study. The three-dimensional angles of the ankle, knee, and hip joints of the outer-leg were calculated using 7 inertial measurement units. The skiing duration and the maximum and minimum values of joint angles were analized in the open-gate, previous gate of hair-pin, 1st gate of hair-pin and 2nd gate of hair-pin. There was a significant difference in the skiing duration, and there were significant differences in the minimum flexion, the maximum abduction, the maximum internal rotation angle of the hip joint, and the minimum flexion angle of the knee joint. Based on the results of this study, the movement of the joints was simplified in the order of the open gate, previous gate of hair-pin, the second gates of hairpin, and the first gate of hair-pin.

알파인 스킹 시 스키딩과 카빙턴 간 무릎의 과사용 상해를 유발할 수 있는 잠재적 위험 요소

김주년 ( Kim Joo-nyeon ),윤석훈 ( Yoon Sukhoon ) 한국체육대학교 체육과학연구소 2020 스포츠사이언스 Vol.38 No.2

Overuse injuries of the knee are a common injuries among alpine ski racers. Especially, outer leg might experience higher force and moment due to its function as steering leg. Racers selectively use skidding turn and carving turn according to the ski length (or ski radius) specified by International Ski Federation rules and the environmental factors of the course. Therefore, This study was investigated to describe 3-dimensional angle of the knee during carving and skidding turns and to assess the plausibility of the hypothesis that a valgus angle might be a potential risk factor leading to overuse injuries of the knee in alpine ski. Ten Korean alpine ski racers were participated in this study. Eight inertial measurement units (myoMOTION, Noraxon, USA) were used to collect segment kinematic data at a sampling frequency of 200 Hz. Inertial measurement units were attached bilaterally to the thigh, shank and foot segments (ski), and to the pelvis and lower-spine under the alpine ski racing suit. Each skier was asked to perform turns including ten carving turns and ten skidding turns on the groomed 15° slope, respectively. The peak valgus angle was calculated the shank angle related to the thigh angle on the anteroposterior axis. The differences between the carving turn and skidding turn were determined using paired t-test (significance level : α<.05), and the effect sizes (Cohen’s d) were calculated. The obtained results indicate that the peak valgus angle of the knee on the outer leg in carving turn (33.96±2.49°) was significantly greater than the peak valgus angle of the knee on the outer leg in skidding turn (26.36±0.44°; t=9.35, p<.05). For the valgus angle between two different turning techniques, the observed power was greater than 0.8 (r=0.957).

마스크 종류와 피로도가 유산소 운동 시 운동학적 변인에 미치는 영향

양진주 ( Jinjoo Yang ),윤석훈 ( Sukhoon Yoon ) 한국체육대학교 체육과학연구소 2021 스포츠사이언스 Vol.39 No.3

The aim of this study was to compare the kinematic differences of the lower extremities according to the type of protective mask worn and fatigue during aerobic exercise (running). Total of 11 adult males (age: 30.4±2.8 yrs., height: 174.3±4.7 cm, weight: 74.7±10.2kg) with no history of heart disease or orthopedic disease participated in this study. All subjects were divided into three classes: not wearing a mask [WM], wearing a KF94 mask [KF94], and wearing a surgical mask [SM]. John’s protocol was applied to induce fatigue state in subject, and kinematic analysis was performed at three fatigue levels (beginning [pre] / RPE14 [mid] / RPE17 [final]) in each condition. For 3D motion analysis, 8 infrared cameras (Oqus 300, Qualisys, Sweden) were used to measure the stride length, frequency, contact time, flight time, and hip/knee/ankle joint angle changes. The results of the gait variable showed significant main effects of fatigue in stride length, contact time, flight time, and frequency (p< .05); however, the main effect of the mask did not show (p >.05). Analysis of the maximum angle of X-axis of hip, knee, and ankle angles showed significant fatigue effect not mask. As a result of this study, the two masks did not have an additional effect on fatigue both at the time when fatigue started and at the time when fatigue intensified, and these results are thought to help the general public to choose a mask to use when exercising.

8주간의 엉덩 관절 유연성 트레이닝이 벨리 댄서들의 힙-쉬미(Hip-Shimmy) 동작에 미치는 영향

송영은 ( Song¸ Young Eun ),윤석훈 ( Yoon Sukhoon ) 한국체육학회 2020 한국체육학회지 Vol.59 No.6

본 연구의 목적은 8주간의 엉덩 관절 유연성 트레이닝 프로그램이 골반 가동 범위 개선에 따른 힙-쉬미동작에 미치는 영향을 알아보는데 있다. 본 연구의 연구 대상자는 벨리댄스 경력 2년 이상이며 6개월 이내에 근골격계 상해가 없는 벨리댄서 22명이었다. 연구대상자는 동수의 NT(Non-Traning)와 TR(Traning)의 두 그룹으로 나누어졌으며, NT그룹은 기존의 일반 벨리댄스 수업프로그램을 TR그룹은 벨리댄스 수업 프로그램에 추가하여 엉덩 관절 유연성 트레이닝 수업을 수행하였다. 본 연구의 목적을 수행하기 위하여 8대의 적외선 카메라를 사용한 3차원 동작분석이 실시되었으며 훈련 효과를 검증하기 위하여 반복측정 이원분산 분석(Two-way ANOVA with repeated measure)이 사용되었다. 통계적으로 유의하게 나타난 항목은 Bonferroni 사후검정을 실시하였으며, 유의 수준은 α= .05로 설정하였다. 본 연구를 수행한 결과, 8주간의 트레이닝 후 TR에서 통계적으로 유의하게 증가된 시상면의 좌, 우 무릎관절 가동범위가 나타났다(오른쪽: 10.79° vs. 20.83°, 왼쪽: 12.67° vs. 22.21°, p<.05). 또한 골반과 몸통분절의 경우, 관상면에서 TR이 훈련 전에 비하여 통계적으로 유의하게 증가된 가동범위를 나타내었을 뿐 아니라(골반: 13.07° vs. 22.87°, 몸통: 1.74° vs. 3.29, p<.05), NT와의 차이도 나타내었다(골반: 16.53° vs. 22.87°, 몸통: 2.22° vs. 3.29°, p<.05). 마지막으로 골반과 몸통분절 모두 트레이닝 후 수평면에서 TR이 NR에 비하여 통계적으로 유의하게 증가된 가동범위를 나타내었으며(골반: 11.69° vs. 15.32°, 몸통: 4.93° vs. 6.59°, p<.05), 특히 몸통분절의 경우 트레이닝 효과도 나타내었다(4.91° vs. 6.59, p<.05). The purpose of this study was to investigate the effect of 8 weeks - hip joint flexibility training program on improving pelvic range of motion. Total of 22 belly dancers who have done belly dancing more than 2 years and had no musculoskeletal injury within 6 months participate this study. After recruiting process, participants were divided into two groups: NT (Non-Traning) and TR (Traning). Both group performed the traditional belly dancing class program and TR performed additional hip flex training. To pursue the study goal, a 3-dimensional motion analysis with 8 infrared cameras was performed. To examine a 8-week training effects, a two-way ANOVA with repeated measure was used. For statistically significant items, Bonferroni’s post hoc test was performed and the significance level was set to α = .05. As a result of this study, after 8 weeks of the training, the range of motion (ROM) of the left and right knee joints of the sagittal plane was significantly increased in TR (p<.05). In addition, in the case of the pelvis and trunk segment, the TR showed a significantly increased ROM after training in the frontal plane as well as the difference from the NT group (p<.05). Lastly, both the pelvis and trunk segments showed a significantly increase in ROM in the transversel plane after training compared to NR, and in particular, the trunk segment showed a training effect (p<.05).

평창동계올림픽 알파인 스키 활강ㆍ슈퍼대회전 코스의 지형 특성 및 경기력 요인에 미치는 영향

김주년 ( Kim Joo Nyeon ),윤석훈 ( Yoon Sukhoon ) 한국체육대학교 체육과학연구소 2019 스포츠사이언스 Vol.36 No.2

The purpose of this study is to quantify the characteristics of the downhill (DH) and super giant slalom (SG) course of Jeongseon Alpine Stadium where the PyeongChang Winter Olympic Games are held, and to investigate the correlation between the characteristics and the skier’s speed. A high level racer who are continuously training at Jeongseon alpine centre and who secured the right to participate in the Olympic Winter Games in PyeongChang participated in the study. The Global Positioning System (GPS) was used to measure the position of the gates of DH and SG, and to collect the skier’s trajectory when he was skiing. The collected latitude, longitude, and altitude data were converted into meter units, and the gate distance, gate shift angle, and gradient were calculated and the correlation between the skier’s speed and course characteristic parameters was calculated. The gate distance was 89.79±37.07 m in DH and 55.85±20.40 m in SG. The gate shift angle was 136.83±19.45° in DH and 147.26±15.54° in SG. The gradient was -18.71±5.93° in DH and -18.90±7.78° in SG. In addition, in the super giant slalom, there was a significant correlation between gate distance and skier’s speed.

전방십자인대 재건술 후 하지관절의 생체역학적 변화 - SPM 통계기법을 활용한 데이터의 재해석

박상헌 ( Sangheon Park ),다어반타우 ( Dao Van Thau ),윤석훈 ( Sukhoon Yoon ) 한국체육대학교 체육과학연구소 2021 스포츠사이언스 Vol.39 No.2

The purpose of this study was to investigate the movement changes in lower extremity according to the ACL reconstruction using kinematic variables and SPM technique. Twenty-one post ACL reconstruction patients ([AG]) and an equal number of healthy adults ([CG]) participated in this study. All participants were asked to perform walking, running, cutting 30°and 60°, respectively. The 3-D joint angle of lower extremity was calculated. In addition, to investigate the movement changed according to ACL reconstruction, discrete variables and continuous variables were verified using independent t-test and 1D-SPM. During walking and running, there was no significant difference according to ACL reconstruction in both discrete variables and continuous variables (p>.05). However, during cutting 30°and 60°, discrete variables and continuous variables showed significant differences in the hip and ankle joint (p<.05). A significant difference was found in the knee joint only in continuous variables using 1D-SPM. Based on these results, it is estimated that AG uses compensatory movements though the movements of the hip and knee joints, which are close to the knee joint, during cutting. Moreover, excessive extension angle of the knee joint during initial contact shown in the continuous variables can effect as a risk factor for re-injury. The results in this study were confirmed more clearly in the verification of continuous variables. It is expected that the verification of continuous variables using 1D-SPM can be used in various ways in future study.

발바닥 부위별 인솔 소재 및 경도 변화가 착화감과 충격 흡수에 미치는 영향

류시현(Sihyun Ryu),길호종(Hojong Gil),공세진(Sejin Kong),최용석(Yongsuk Choi),류지선(Jiseon Ryu),윤석훈(Sukhoon Yoon),박상균(Sang Kyoon Park) 대한인간공학회 2018 大韓人間工學會誌 Vol.37 No.4

Objective: The purpose of this study was to evaluate the biomechanical effects of insole material and hardness in different plantar regions on the comfort and impact absorption during walking and to analyze the correlations between comfort and impact variables. Background: It is necessary to apply materials tailored to the functionalities of different plantar regions during different phases of the gait cycle: the rearfoot portion should absorb the impact force during the heel-contact phase, the midfoot portion should support the entire arch, and the forefoot portion should enhance the swing efficiency during the toe-off phase. Method: Twenty men in their twenties were recruited for the study (age: 23.4±2.7yrs; height: 175.9±4.1㎝; weight: 72.9±9.4㎏). They wore insoles in random order. Pedar-X system (Novel GmbH, USA) and Treadmill (Instrumented treadmill, Bertec, USA) were used to measure the plantar pressure and ground reaction force. The walking speed was set at 1.3㎧ and 1.7㎧. The sampling rate was set at 50㎐ and 1,000㎐, respectively. For comfort testing, the subjects administered a questionnaire survey using the visual analogue scale (VAS) after walking 1km. Three insole models were tested: Insole A using a mixed material with shock-absorbing and anti-rebound components uniformly spread throughout the insole; Insole B and Insole C using sponge and ethylene vinyl acetate (EVA), respectively, as underlying material and strengthened with shock absorber in the rearfoot portion, high-hardness material in the midfoot portion, and anti-rebound function in the forefoot portion. The impulse, mean impact force, initial peak of ground reaction force, and loading rate were calculated. Results: First, Insole B significantly outscored Insole A in terms of the forefoot cushioning comfort (p <.05), with Insole B and C showing higher overall comfort scores compared with Insole A (p <.05). Second, Insole A showed higher mean impact force, initial and peak vertical ground reaction forces, and loading rate compared with Insoles B and C, but without reaching statistical significance. Third, Insole B and C showed statistically higher mean pressure in the midfoot portion compared with Insole A (p <.05). Conclusion: Positive effects in terms of comfort and impact absorption were demonstrated by the insoles fabricated with different materials and hardness tailored to the functionalities of different plantar regions in comparison with the conventional insoles using the uniform material throughout the insole. In particular, positive effects on overall comfort were found to be ascribable to the enhanced hardness in the midfoot portion, which supported the arch more efficiently and contributed to an even distribution of the overall pressure on the plantar. Application: The study results can be applied to insole development as follows: Insole material and hardness should be varied for different plantar regions, and shock absorber and high-hardness material should be used for the rearfoot and midfoot portions, respectively.