• Korean Journal of Applied Biomechanics
• /
• v.12 no.2
• /
• pp.215-227
• /
• 2002

The purpose of this study was to investigate propulsive time and kinematic variables on the three different kinds of the basketball wheelchairs in each play position for eight abled basketball wheelchair players. Kinematic data were collected by a video camera for two-dimensional analysis. The wheelchairs for the guard position showed the fastest in total propulsive time. The wheelchairs for the center position revealed the slowest in the phase of the change of the direction. The wheelchair for the guard position which shows fast movement velocity demonstrated closer hand contact with TDC(Top Dead Center). The wheelchair for the center position revealed the largest extension of the elbow and flexion of the trunk at handrim contact. The wheelchair for the guard position which has the lowest seat height presented larger elbow angle and trunk angle. The wheelchair for the guard position produced more fast trunk angular velocity than the wheelchair for other positions.

• Korean Journal of Applied Biomechanics
• /
• v.13 no.3
• /
• pp.81-98
• /
• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• The Journal of the Korea Contents Association
• /
• v.10 no.10
• /
• pp.440-450
• /
• 2010

This study was an analysis of sport psychological application for the kinesthetic gifted children's selection and upbringing in Pusan University's center for kinesthetic gifted children from 2009.7 to 2010.2. The 60(athletics: 40, swimming: 10, gymnastics: 10) of kinesthetic gifted children were selected among the first, second and third year students from Pusan, Ulsan and Kyungsang-namdo without distinction of sex. We progressed summer and winter camp during vacation, and managed a special training program according to exercise items on every Saturday. We attempted experimental a field application, and obtained the following implications. First, the first and second year students were possible to test psychological measurement with supplementary explanation, and in the case of third grade, it was enough possible without any supplementary explanation. Second, multi-intelligence test was efficient as the method to check kinesthetic gifted children's intelligence and useful as the basic data for counseling. Third, the character types of kinesthetic gifted children were appeared preferring outgoing, intuition and emotions. Forth, with the FAIR concentration, we confirmed that the center's program effected positively on improving concentration. Fifth, we found the potential that the physical task commitment questionnaire and the exercise activity self-administer questionnair would be used as official psychological measurement tool after the review process of additional validity and reliability.

• The Journal of Korean Society for School & Community Health Education
• /
• v.2 no.2
• /
• pp.39-55
• /
• 2001

The purpose of this study was to provide the necessary fundamental data in composing a systematic text content of the public health by analyzing each text, domain, and teaching contents suggested in the textbooks as well as teachers' guides of the 7th elementary school education curriculum, while the study subjects were as follows. 1. The health education content suggested in the 7th physical education curriculum were analyzed and examined. 2. The health teaching content of each textbook in the 7th elementary school curriculum was to be analyzed and examined. In order to resolve the above research issues, the physical, spiritual, and social domain along with the (1) Proper living habit, (2) Health and nutrition, (3) Sex education, (4) Prevention of the sense-organic diseases, (5) Cleanliness of food, (6) Oral hygiene, (7) Individual health and public health, (8) Safety in living, (9) Abuse and usage of medication, educational content suggested in the 7tand (10) Environment pollution focused around the health of the elementary school education curriculum was analyzed and its outcome was as below First, compared with the 6th elementary school education curriculum, the health content suggested in the 7th elementary school education curriculum was decreased. Second, although each grade's teaching content of the health domain in the physical education was considered in its structure following after the according systems, they were preponderant in partial subjects such as the safety in living, nutrition, proper living habit, sport, and health in sport. oo. Third, the health education content was organized in 4 units such as the physical growth and development, prevention of diseases, safe living, and leisure living(leisure, spiritual health, and etc.) for the 3rd and 4th grade. Then, as for 5th and 6th grade, it was organized in 3 units such as the understanding the human body, prevention of disease, and leisure and safe living. Fourth, in the physical educational health domain, a strong point was constructed within the physical, spiritual, and social areas of the elementary school physical education. Fifth, the number of the public health education contents directly related with the health education was 43 as with 25 indirect contents. Sixth, each grade's domain unit structure of the public health content was heavy upon the physical and social area throughout every grade while in opposite, the spiritual domain' s unit structure was weak. In according to each grade, the physical domain was stressed in 4, 5, and 6 grades while the social domain was stressed in 1, 5, and 6 grades.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.3
• /
• pp.335-342
• /
• 2015

Objective : The purposes of this study was to analyze the effects of the stirrup length fitted to the rider's lower limb length and it's impact on less skilled riders during trot in equestrian events. Methods : Participants selected as subjects consisted of less skilled riders(n=5, mean age: $40.02{\pm}10.75yrs$, mean heights: $169.77{\pm}2.08cm$, mean body weights: $67.65{\pm}7.76kg$, lower limb lengths: $97.26{\pm}2.35cm$, mean horse heights: $164.00{\pm}5.74cm$ with 2 type of stirrups lengths(lower limb ratio 74.04%, and 79.18%) during trot. The variables analyzed consisted of the displacement for Y axis and Z axis(head, and center of mass[COM]) with asymmetric index, trunk front-rear angle(consistency index), lower limb joint(Right hip, knee, and ankle), and average vertical forces of horse rider during 1 stride in trot. The 4 camcorder(HDR-HC7/HDV 1080i, Spony Corp, Japan) was used to capture horse riding motion at a rate of 60 frames/sec. Raw data was collected from Kwon3D XP motion analysis package ver 4.0 program(Visol, Korea) during trot. Results : The movements and asymmetric index didn't show significant difference at head and COM, Also, 74.04% stirrups lengths in trunk tilting angle showed significant difference with higher consistency than that of 79.18% stirrups lengths. Hip and knee joint angle showed significant difference with more extended posture than that of 74.04% stirrups lengths during trot. Ankle angle of 79.18% stirrups length showed more plantarflexion than that of 74.04% stirrups lengths. Average vertical force of rider showed significant difference with higher force at 79.18% stirrups lengths than that of 74.04% stirrups lengths during stance phase. Conclusion : When considering the above, 74.04% stirrups length could be effective in impulse reduction with consistent posture in rather less skilled horse riders.

• Korean Journal of Applied Biomechanics
• /
• v.27 no.2
• /
• pp.117-124
• /
• 2017

Objective: The purpose of this study was to examine the effect of changes in degrees of freedom of the fingers (i.e., the number of the fingers involved in tasks) on the task performance during force production and releasing task. Method: Eight right-handed young men (age: $29.63{\pm}3.02yr$, height: $1.73{\pm}0.04m$, weight: $70.25{\pm}9.05kg$) participated in this study. The subjects were required to press the transducers with three combinations of fingers, including the index-middle (IM), index-middle-ring (IMR), and index-middle-ring-little (IMRL). During the trials, they were instructed to maintain a steady-state level of both normal and tangential forces within the first 5 sec. After the first 5 sec, the subjects were instructed to release the fingers on the transducers as quickly as possible at a self-selected manner within the next 5 sec, resulting in zero force at the end. Customized MATLAB codes (MathWorks Inc., Natick, MA, USA) were written for data analysis. The following variables were quantified: 1) finger force sharing pattern, 2) root mean square error (RMSE) of force to the target force in three axes at the aiming phase, 3) the time duration of the release phase (release time), and 4) the accuracy and precision indexes of the virtual firing position. Results: The RMSE was decreased with the number of fingers increased in both normal and tangential forces at the steady-state phase. The precision index was smaller (more precise) in the IMR condition than in the IM condition, while no significant difference in the accuracy index was observed between the conditions. In addition, no significant difference in release time was found between the conditions. Conclusion: The study provides evidence that the increased number of fingers resulted in better error compensation at the aiming phase and performed a more constant shooting (i.e., smaller precision index). However, the increased number of fingers did not affect the release time, which may influence the consistency of terminal performance. Thus, the number of fingers led to positive results for the current task.

• Korean Journal of Applied Biomechanics
• /
• v.17 no.4
• /
• pp.201-208
• /
• 2007

The purpose of this study is to compare 4 different body punch types(type 1: a punch using a shoulder, type 2: a punch using a waist, type 3: a punch using lower extremities, and type 4: a punch with elbows by your side at chest level) in horseback-riding stance and establish suitable teaching theory and method, which would be a useful reference to Taekwondo instructors on the spot(in Taekwondo dojangs all around Korea). Five exhibition players from Korean national Taekwondo exhibition team participated in this study. Each participant was asked to perform the four different types of punches and their kinematic and kinetic data were recorded with 7 vicon cameras(125Hz) and two force plates(AMTI, 1200Hz). We analyzed displacement, time, resultant center of body mass trajectory, velocity, trunk angular velocity, and ground reaction force(GRF) from each body segment in body punch and the result. I performed 1-way ANOVA(RM) for average values of each player after standardization and statistical significance was set as p<.05. was as the following ; First, they showed a tendency to take the body punch posture with the biggest motion at a shoulder and on descending order a waist and a knee. Second, a mean time for each body punch on ascending order 0.46sec. for type 2, 0.49sec for type 3, 0.50sec. for type 4, and 0.56sec. for type 1. Third, a mean resultant center of body mass trajectory for each body punch the longest 4.07cm for type 3 and the shortest 2.458cm for type 1. Fourth, a mean of maximal velocity of a fist strike was the fastest 5.99m/s for type 3, 5.93m/s for type 4, 5.67m/s for type 2, and 5.01m/s for type 1 on the descending order. Fifth, a mean of maximal trunk angular velocity of the fastest 495.6deg./sec. for type 4 and 337.7deg./sec. for type 1 on the descending order. Sixth, strongest value was type 3, 2 for anterior-posterior ground reaction force(left -54.89N, right 60.58N), type 4 for medial-lateral GRF(left 83.59N, right -80.12N), and type 3 for vertical GRF(left 341.79N, right 426.11N).

• Korean Journal of Applied Biomechanics
• /
• v.19 no.4
• /
• pp.771-778
• /
• 2009

We aimed to determine the effect of heel height on foot pressure by comparing and analyzing data on foot pressure in shoes with different heel heights. Qn the basis of a previous study, we selected 3cm and 7cm as the shoe heel heights preferred by female college students. We divided 10 female students into forefoot and hindfoot to measure vertical force, maximum pressure, and average pressure. The average pressure on the forefoot was higher and that on the hindfoot was lower in the case of 7cm high-heeled shoes. The maximum pressure on the forefoot was significantly higher in the case of the 7cm heel height (p<.05). The vertical force, maximum pressure, and average pressure on the hindfoot were also significantly higher in the case of the 7cm heel height (p<.05). The results showed that wearing 7cm high-heeled shoes exerted greater maximum pressure on the forefoot and greater vertical force, maximum pressure, and average pressure on the Hndfoot. This leads to increase in confining pressure caused by high pressure distribution over the forefoot and increase in the pressure on the hindfoot, which may cause deformation of toes and heel pain over a long period. Therefore, female college students who wish to wear high heels are recommended to wear 3cm high-heeled shoes rather than 7cm high-heeled shoes.

• Korean Journal of Applied Biomechanics
• /
• v.16 no.1
• /
• pp.31-41
• /
• 2006

The primary purpose of a TKA is to restore normal knee function Therefore, ideally, a TKA should: (a) maintain the natural leverage of the knee joint muscles to ensure generating adequate knee muscle moments to accomplish daily tasks such as rising from climbing stairs; (b) provide adequate knee joint stability. A 16-channel MyoResearch XP EMG system was used to collect the differential input surface electromyography signals VM, VL, RF, BF, ST during climbing/descending stair tests. A Peak Motion Measurement System was used to collect the kinematic and kinetic data. AKIN-COM Ill isokinetic dynamometer was used for EMG of VM, VL, RF, BF and ST during maximal voluntary contraction. I Quadriceps EMG results for the VM of the passed 1year group limb demonstrated significant less RMS EMG than that of the passed 3year group limb $60^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The VL of the passed 1year group limb also demonstrated significants less RMS EMG than that of the passed 3year group limb from $60^{\circ}-45^{\circ}$ of knee flexion(p<0.05). Similar to the VM and VL, the RF of the passed 1year group limb showed less RMS EMG than that of the passed 3year group limb from $60^{\circ}-30^{\circ}$ do knee flexion(p<0.05). Hamstring EMG results for the BF of the passed 1year group limb demonstrated less RMS EMG than that of the passed 3year group limb from $75^{\circ}-15^{\circ}$ of knee flexion(p<0.05). The passed 1year group limb tended to have less ADD displacement(p<0.071) than that of the passed 3year group limb. There was no significant difference of the ABD displacement between the passed 1year group and the passed 3year group limbs(p<0.73). The passed 3year group used compensatory adaptation movement strategies to compensate for the strength deficit of passed 3year group limbs. The passed 3year group limb also increased the quadriceps muscle activation level to produce more knee extension moment to compensate for the short quadriceps moment arm. The passe 3year group limb might have an unstable knee joint in the medio-Iateral direction during the climbing/descending by showing a tendency of more ADD displacement and greater hamming co-activation EMG than the passed 1year group limbs. The TKA design was not able to help the knee joint to produce adequate knee extension moment with less quadriceps muscle effort. I think that old man needs continuous exercise for muscle strength.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.2
• /
• pp.297-309
• /
• 2009

The study analyzed the mechanism of plantar foot pressure distribution during pitching wedge swinging on a flat, an up hill lie and a down hill lie to provide the fundamental information regarding biomechanical motion data by using plantar foot pressure measuring instrument. In the results, time factor spanning according to slope differences, plantar foot pressure factor and swing motion on the slope could have negative effect on the coiling of lower limbs during back swing, as well as the blocking of the lower limbs to minimize the dispersion of the weight and the release of the lower limbs after the impact during the down swing process. Moreover, since slope is one of many external factors affecting swing motion, address motion on an up hill lie limits the lower limbs movement, therefore, a relatively narrow stance is better on a down hill lie. It is estimated that a relatively wide stance would be better in order to limit the bigger activation of the lower limbs. Not only for the address motion but also during the down swing on an up hill lie it is concluded that the weight should be on the left foot in order to keep the body balance.