• 한국운동역학회지
• /
• 제18권2호
• /
• pp.41-48
• /
• 2008

본 연구의 목적은 테니스 두 스탠스 유형(pinpoint stance, platform stance)에 따른 서브 시 하지관절의 모멘트를 분석하여 테니스 선수들이 연습 시 상해를 예방할 수 있도록 현장에서 지도할 객관적인 기초자료를 얻기 위해 테니스 고등학교 우수선수 7명을 대상으로 하였으며, VICON System의 분석프로그램인 Workstation, Bodybuilder, Polygon을 이용하여 하지관절의 모멘트를 분석하였다. 구체적인 변인은 발목, 무릎, 엉덩관절의 모멘트들을 중점적으로 비교 분석한바 다음과 같은 결론을 얻었다. 테니스 두 스탠스 유형에 따른 서브 동작 시 하지관절에 발생되는 모멘트의 패턴은 각각 다른 패턴이었으며, 모멘트의 크기는 발목 배측 굴곡 모멘트만 plat가 크게 발생되었으며, 다른 모멘트는 pin이 크게 발생되었다. 또 굴신모멘트에서는 엉덩, 발목, 무릎 순이었으며, 회전모멘트는 발목, 무릎, 엉덩 순으로 큰 모멘트를 나타내 보였다. 하지관절의 굴신과 회전모멘트는 백스윙동작과 백스윙동작부터 포워드 스윙으로 변화되는 시점까지 모멘트의 크기가 가장 크게 나타났으며, 변화도 크게 나타내보였다. 이때 상해가 발생할 위험성이 높기 때문에 이에 주의해야 한다고 사료된다.

• 한국운동역학회지
• /
• 제16권4호
• /
• pp.31-38
• /
• 2006

The purpose of this study was to investigate the effect of changing the steps height on the joint moment of lower extremity in stair-descent activity of elderly persons. Data were collected by 3-D cinematography and force platform. 9 male elderly subjects in the 60s and 70s participated in this study. All subjects performed a stair-descent in four different heights of stairs (10, 14, 18, 22cm) having 5 step staircase. The results were as follows. 1. For the step height of 22cm the maximum. plantarflexion moment was the smallest and the largest for the step height of 14cm. 2. There was not a statistical difference shown for the extension moment of the knee joint for the different height of steps. 3. There was not a statistical difference shown for the flexion moment of the hip joint for the varying height of steps but on average for the 18cm step this increased rapidly. 4. The smallest maximum. value for inversion moment was revealed for the step height of 10cm and this increased significantly for the step height of 22cm. 5. The smallest maximum. value for abduction moment of the hip joint was revealed for the step height of 10cm and this increased significantly for the step height of 22cm. 6. There was no significant difference shown for the maximum. abduction moment for the hip joint. The main conclusion is that there is a huge difference in the moment of the lower extremities for the elderly while walking down a stairs with a step height above 18 cm and that this moment increased or decreased rapidly under a condition of step height being 22cm. With the results from this research and related research of elderly walking upstairs it can be shown that the step height has a large role in the safety for the elderly.

• 한국전문물리치료학회지
• /
• 제18권2호
• /
• pp.1-8
• /
• 2011

The purpose of this study was to investigate the effect of high heeled shoes with the total contact insert (TCI) on the frontal plane of the joints for the lower extremity during the gait. Ten healthy females voluntarily participated in this study and the height of the high heeled shoes was 7 cm. A three-dimensional motion analysis system (VICON) and force plates were used to analyze the movements of the joints for the lower extremities. The results were as follows: There were no significant differences for the angle value on the event of the gait cycle in the maximum eversion and inversion of the ankle joint, the varus and valgus of the knee joint, and the adduction and abduction of the hip joint (p>.05). But, there was a significant difference or the range of motion in the ankle joint (p<.05). The value of ankle and knee moment with a TCI was less than the value for no TCI. And there were significant differences for the moment value of the maximum inversion and eversion on the ankle joint and for the maximum varus and valgus on the knee joint (p<.05). Therefore, a TCI would be effective in stabilizing the joints of the lower extremities and increasing the balance of a body to reduce the injure from a fall during the gait.

• 대한물리치료과학회지
• /
• 제10권2호
• /
• pp.53-61
• /
• 2003

The purposes of this study were to describe and compare pint moments according to 6 types of gait methods during free speed. 15 volunteers(7 male, 8 female: mean age = 23.33 yrs.) participated and performed 6 types of gait methods. From the 3 types of pint moments of lower extremities(hip, knee, ankle and foot), the following results were made: 1. In left hip pint, the flexion-extension moment was not significantly different, but the adduction-abduction moment and rotation moment were showed different curves during stance phase. 2. In left knee pint, the flexion-extension moment was not significantly different, but the varus-valgus moment and rotation moment were showed different curves during stance phase. 3. In left ankle and foot the dorsiflexion-plantarflexion moment was not significantly different but the varus-valgus moment and rotation moment were showed different curves during stance phase. In conclusion, because weight loading gait with 10-20% of body weight were normal gait patterns, It was inferred that all weight loading gaits did not indicate noxious reactions of human body.

• 한국운동역학회지
• /
• 제17권2호
• /
• pp.187-196
• /
• 2007

The purpose of this study was to find the most effective movement pattern from three different types of preparatory movement(squat, countermovement and hopping) in sideward responsive propulsion task, which had the time constraint to complete the performance. 7 healthy subjects participated in left and right side movement task by an external signal, which required the subject to perform the task as fast as possible. Mechanical output and joint kinetics focusing on the lower extremities were analyzed. The results were as follows. In spite of the shortest duration in propulsive phase, the hopping condition showed no difference with other conditions in the work output done and take-off velocity. It resulted from the greatest power output generated during the propulsive phase. A significant difference was found for joint moment and joint power according to the movement conditions. The joint moment and joint power for the countermovement and hopping conditions were larger than those in the squat condition. This was speculated to be due to the extra power that could be generated by the pre-stretch of muscle in preparation for the propulsion. The hopping condition which had substantially more pre-stretch load in the preparatory eccentric phase produced considerably more power than countermovement condition in the propulsive concentric phase. Furthermore during the hopping a large amount of joint moment and joint power could be produced in a shorter time. Therefore it was deemed that the hopping movement is an effective type of preparatory movement which takes much more advantage of the pre-stretch than any other movement.

• 한국운동역학회지
• /
• 제18권2호
• /
• pp.75-83
• /
• 2008

본 연구의 목적은 보행 속도의 차이에 따른 최대 관절 모멘트와 최대 모멘트 발생 시점의 관절 각도 상관관계를 규명하는데 있다. 8명의 $20{\sim}30$대 남성을 대상으로 보행 속도의 3가지 단계(1.5m/s, 1.8m/s, 2.1m/s)를 나누어 속도에 따른 보행을 실시하여 얻어진 결론은 다음과 같다. 1. 보행 속도가 증가함에 따라 무릎 최대 신전 모멘트는 증가하였고, 굴곡, 외전 모멘트는 큰 영향을 받지 않았다. 2. 최대 신전 모멘트가 발생하는 시점의 무릎 관절 각도는 굴곡의 움직임이 커졌으나, 다른 무릎 관절 각도에는 변화가 없었다. 3. 힙 최대 신전, 굴곡, 외전 모멘트는 증가하였다. 4. 최대 굴곡과 신전 모멘트가 발생하는 시점의 힙 관절 각도의 신전과 굴곡의 증가 현상을 보였으나, 최대 외전 모멘트가 발생하는 시점의 무릎 관절 각도에는 변화가 없었다. 5. 무릎 최대 신전, 굴곡, 외전 모멘트와 무릎 관절 각도를 least square method를 이용하여 적합도 검사를 실시한 결과 R2값이 높게 나타나 상관관계의 설명력이 높았다. 이렇게 근사된 곡선의 근사식은 보행 속도에 따른 무릎 관절의 평가 자료로 이용될 것으로 기대된다.

• The Journal of Korean Physical Therapy
• /
• 제11권1호
• /
• pp.55-61
• /
• 1999

The purpose of this study was to compare the moment and power of affected Side and those of unaffected side during gait in hemiplegic patients after stroke. Force plate ana kinetic gait analysis was used. The following is resulted from this study. 1. In the hip joint, moment values had not difference between affected side and unaffected side. Power values had difference between affected and unafected side. 2. In the knee joint, moment values and power values had difference between affected side and unaffected side. 3. In the ankle feint, moment and power values had not, difference between affected side and unaffected side.

• 한국운동역학회지
• /
• 제17권2호
• /
• pp.157-166
• /
• 2007

This study was to compare the major kinematic factors between the success and failure group on performing the back somersault motion in floor exercise. Three gymnasts(height : $167.3{\pm}2.88cm$, age : $22.0{\pm}1.0years$, body weight : $64.4{\pm}2.3kg$) were participated in this study. The kinematic data was recorded at 60Hz with four digital video camera. Two successful motions and failure motions for each subject were selected for three dimensional analysis. 1. Success Trail It was appear that success trail was larger than failure group in projection velocity, but success trail was smaller than failure trail in projection angle. Also it was appear that success trail was longer than failure group in the time required. Hand segment velocity and maximum velocity in success trail were larger than those in failure trail, and this result was increasing the projection velocity and finally increasing the vertical height of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle was contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle was maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of success trail extended more than those of failure trail. in this base, success trail in upward phase(p3) 2. Failure Trail It was appear that failure trail was smaller than success trail in projection velocity, but failure trail was larger than success trail in projection angle. Also it was appear that failure trail was more short than success trail in the time required. Hand segment velocity and maximum velocity in failure trail were smaller than those in success trail, and this result was reducing the projection velocity and finally reducing the vertical high of center of mass. At the take-off(event 2), flection amount of hip and knee joint angle wasn't contributed to the optimal condition for the take-off and at the peak point, hip and knee joint angle wasn't maximum flexed for reducing the moment of inertia. Also in this point, upper extremities of failure trail didn't extended more than those of success trail.

• 한국운동역학회지
• /
• 제16권3호
• /
• pp.105-115
• /
• 2006

The purpose of this study is to elucidate the mechanical characteristics of lower extremity joint movements at different walking speeds in obese people and suggest the very suitable exercise for obese person's own body weight and basic data for clinical application leading to medical treatment of obesity. This experimental subjects are all males between the ages of 20 and 30, who are classified into two groups according to Body Mass Index(BMI): one group is 15 people with normal body weight and the other 15 obese people. Walking speed is analysed at 3 different speeds ($1.5^m/s$, $1.8^m/s$, $2.1^m/s$) which is increased by $0.3^m/s$ from the standard speed of $1.5^m/s$. We calculated joint moments of lower extremity during stance phase through video recording and platform force measurement.Two-way ANOVA(Analysis of Variance, Mix) is applied to get the difference of moments according to walking speeds between normal and obese groups. Pearson's Correlation Analysis is applied to look into correlation between walking speeds and joint moments in both groups. Significance level of each experiment is set as ${\alpha}=.05$. As walking speed increases maximum ankle plantar flexion moment in the stance phase is smaller in obese group than in normal group, which is suggestive of weak toe push-off during terminal stance in obese group, and the highest maximum ankle plantar flexion moment in obese group during the middle speed walking($1.8^m/s.$). Maximum ankle dorsal flexion moment in obese group is relatively higher than in normal group and this is regarded as a kind of compensatory mechanism to decrease the impact on ankle when heel contacts the floor. Maximum knee flexion and extension moments are both higher in normal group with an increase tendency proportional to walking speed and maximum hip flexion and extension moments higher in obese group. In summary, maximum ankle plantar flexion moment between groups(p<.025), maximum knee moment not in flexion but in extension(p<.001) within each group according to increasing walking speed, and maximum hip flexion and extension moment(p<.001 and p<.004, respectively according to increasing walking speed are statistically significant but knee and hip moments between groups are not. Pearson correlation are different: high correlation coefficients in maximum knee flexion and extension moments, in maximum hip extension moment but not hip flexion, and in maximum ankle dorsal flexion moment but not ankle plantar flexion, in each group. We suspect that equilibrium imbalance develops when the subject increases walking speed and the time is around which he takes his foot off the floor.

• 대한안전경영과학회지
• /
• 제15권4호
• /
• pp.153-160
• /
• 2013

The purpose of this study was to compare biomechanical factors on badminton shoes between anti-slip outsole and non anti-slip outsole. Six subjects participated in this experiment. For three-dimensional analysis, eight cameras (Oqus 3series, Qualisys) were used to acquire raw data, and then the parameters were calculated and analyzed with Visual-3D. In conclusion, the patterns of spent time during side step, and maximum velocities of CoGs were consistent without joint angles of lower extremities in spite of small differences. Those of GRFs, and moment of lower extremities were absolutely consistent. This trend of biomechanical factors was that Y shoe (ante-treatment) was much greater and PS shoe (treatment) was greater than Y shoe (treatment). (That was, Y shoe (ante-treatment) > PS shoe (treatment) >Y shoe (treatment)). The findings of this study showed that anti-slip outsole was effective and brought increasing performance and decreasing injuries. It is suggested that further study of these phenomena will help understand many aspects of human locomotion, including work, performance, fatigue and possible injuries.