• 대한방사선기술학회지:방사선기술과학
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• 제43권3호
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• pp.161-167
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• 2020

This study aimed to found out the effect of patellofemoral overlap distance by changing femur thickness and center X-ray angles in Merchant method images. Based on the femur thickness, it suggested tube angle minimizes overlap. It was conducted by Merchant method, a knee tangential view, and the image was obtained by changing the thigh thickness from 14 to 20 cm and the center ray angle from 60°, 57°, 55°. The images were measured by five researchers using a method of measuring the overlap, which was designed by them. The results showed at 60°, 57°, 55° angle, the patellofemoral overlap distance resulted in 0.47±0.66 to 20.89±0.65 cm, 2.26±0.28 to 15.73±0.62 cm, 1.39 ± 0.83 to 12.49 ± 0.37 cm. However, for 57° and 55°, no overlap in thickness under 14.5 and 14 to 15.5 didn't appear. it showed high correlation between femur thickness and overlap. The difference in the mean value of overlap in each group showed a statistically significant difference (p<0.01), all were classified as independent groups in the post-hoc test. In all images, the patellofemoral overlap distance increased as the thickness increased, and at the average thickness of Korean men and women, overlap decreased when reducing center ray. When conducting Merchant tests on Koreans, it was suggested it would be useful to use 57° angle because it minimize the effects of overlap and intrusions of tibia.

• 한국전문물리치료학회지
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• 제12권1호
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• pp.28-35
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• 2005

The purpose of this study was to determine whether gender differences existed in knee valgus kinematics in college students when performing a vertical drop landing. The hypothesis of this study was that females would demonstrate greater knee valgus motion. These differences in knee valgus motion may be indicative of decreased dynamic knee joint control in females. This study compared the initial knee valgus angle and maximum knee valgus angle at the instant of impact on vertical drop landings between healthy men and women. In this study, 60 participants (30 males, 30 females) dropped from a height of 43 cm. A digital camera and two-dimensional video motion analysis software were used to analyze the kinematic data. There was significant difference in the mean knee valgus angle at initial contact landing between the two groups (Mean=$7.88^{\circ}$, SD=$4.24^{\circ}$ in males, Mean=$12.93^{\circ}$, SD=$2.89^{\circ}$ in females). The range of knee valgus angle on landing (Mean=$3.25^{\circ}$, SD=$5.72^{\circ}$ in males, Mean=$11.44^{\circ}$, SD=$6.39^{\circ}$ in females) was differed significantly (p<.05). The maximal angle of knee valgus on landing (Mean=$10.91^{\circ}$, SD=$6.89^{\circ}$ in males, Mean=$24.25^{\circ}$, SD=$6.38^{\circ}$ in females) was also differed significantly (p<.05). The females landed with a larger range of knee valgus motion than the males and this might have increased the likelihood of a knee injury. The absence of dynamic knee joint stability may be responsible for increased rates of knee injury in females. No method for accurate and practical screening and identification of athletes at increased risk of ACL injury is currently available to target those individuals that would benefit from neuromuscular training before sports participation.

• 한국컴퓨터정보학회논문지
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• 제18권5호
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• pp.53-60
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• 2013

본 논문에서는 키넥트 센서에 의해 획득한 스켈레톤 정보를 이용하여 스노보드 동작을 시각화 할 수 있는 도구를 제안한다. 스노보드 동작에서 가장 기본이 되는 동작은 BBP(Balanced Body Position)자세로서 안정된 턴 동작을 위한 기본 기술이다. 본 논문에서는 BBP자세를 분석하여 가장 이상적인 동작을 실현할 수 있는 시각화 도구를 구현한다. 키넥트 센서로 부터 획득한 좌표정보를 이용하여 발목, 무릎, 엉덩이 관절의 각도와 몸의 중심축을 추적하여 표준 자세와 비교분석한다. 분석결과는 OpenGL 라이브러리를 통하여 최종 결과 화면을 구성하였다. 본 연구결과는 스노보드 턴 동작을 분석하는 기초자료로 활용될 수 있을 것이다.

• 대한물리치료과학회지
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• 제1권2호
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• pp.289-299
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• 1994

This study was researched the general characteristics, the elbow-knee joint form, the varus and valgus angle and the both knee joint distance of the 215 persons form July 1, 1994 to July 15, 1994. The results were as follows : 1. The form of elbow joint was significant statistically in the sex group(p<0.05). 2. The angle of elbow joint was very significant statistically in the age group and sex. B.M.I. group(p<0.001, p<0.01, p<0.01), and the average angle was $9^{\circ}.51{\pm}4^{\circ}.79$(n=215). 3. The angle of Cubitus valgus was very significant statistically in the age group(p<0.001), and the average angle of Cubitus valgus was $10^{\circ}.85{\pm}3^{\circ}.76$(n=187). 4. The angle of Knee joint was significant statistically in the age group(p<0.05), and the its average angle was $7^{\circ}.63{\pm}4^{\circ}.52$(n=215). 5. The angle of Genu varus was significant statistically in the age and sex group(p<0.05, p<0.05), and the its average was $6^{\circ}.92{\pm}2^{\circ}.36$(n=27). 6. The angle of Genu valgus was very significant statistically in the age group(p<0.001), and the its average angle was $9^{\circ}.75{\pm}2^{\circ}.94$(n=149). 7. The distance of both Knee joint was significant statistically in the age group and B. M. I. group (p<0.001, p<0.05), and the its average distance was $2.55{\pm}1.45cm$(n=135).

• The Journal of Korean Physical Therapy
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• 제23권1호
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• pp.13-19
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• 2011

Purpose:This study was designed to investigate difference in isokinetic muscle strength in the knee extensor muscle and characteristic differences in muscle strength between males and females through the ankle joint angles. Methods: Seventy-four subjects participated in this study. There were two groups: 36 males and 38 females. The mean age of the men was 24.58 years and women was 23.74 years. Subjects were seated on a CON-TREX LP (leg press) lean to back of chair, and there bodies were fixed by straps with the hip joint at an angle of $130^{\circ}$. After randomly fixing the ankle joint at $0^{\circ}$, $20^{\circ}$, and $40^{\circ}$ of plantar flexion (PF) in range of full extension of knee joint. We studied force max average, force max average/kg, power average, and total work through the angle of the ankle joint when the knee joint was extended from $90^{\circ}$ to $180^{\circ}$. Results: In the male group, all maximum measured value showed at the ankle joint $0^{\circ}$, all minimum measured value showed at $40^{\circ}$ PF (p<0.01). In the female group, all maximum measured value showed at the ankle joint $20^{\circ}$ PF, especially the power average increased significantly. All minimum measured value showed $40^{\circ}$ PF (p<0.01). Conclusion: There are differences between males and females in isokinetic muscle strength of the knee extensor through ankle joint angles in healthy adults. Males and Females have different characteristics of muscle strength through the ankle joint angles.

• PNF and Movement
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• 제19권1호
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• pp.79-86
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• 2021

Purpose: The purpose of this study was to investigate muscle activity according to knee flexion angle during single-limb-deadlift exercises. Methods: In total, 26 healthy volunteers participated. The single-limb-deadlift consisted of 0˚, 15˚, and 30˚ knee joint bending. The electromyography data were collected from the semitendinosus (SM), the biceps femoris (BF), the rectus femoris (RF), the vastus lateralis (VL), and the vastus medialis (VM). In addition, hamstrings and quadriceps (HQ) ratio was measured during the single-limb-deadlift using electromyography. Results: During the single-limb-deadlift, RF, VL, and VM were significantly higher at 30˚ bending angles compared to muscle activity of 0˚ and 15˚ knee-joint bending. The HQ ratio had significant differences in all three knee joint bending angles. In particular, the single-limb-deadlift carried out to a 30˚ knee-joint bend showed the closest value to 1. Conclusion: The most balanced coactivation ratios were observed during a single-limb-deadlift to a 30˚ knee-joint bend angle. A single-limb-deadlift at a knee-bend angle of less than 30˚ could be used as an exercise to prevent ACL injury. It could also be used for post-injury rehabilitation programs by increasing knee-joint stability.

• 대한정형도수물리치료학회지
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• 제24권2호
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• pp.75-81
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• 2018

Background: The purpose of this study was to investigate the effect of various relaxation techniques on various dysfunction problems caused by shortening of the sagittal muscles. Method: The subjects were 44(18 males, 26 females). The subjects were composed of 3 groups. The experimental group consisted of 14 patients with proprioceptive neuromuscular facilitation stretching (PNF) technique, control group A 15 patients with self myofacial release (SMR) ball exercise, and control group B with 15 patients with Sling exercise. After 3 weeks of relaxation on the hamstring muscle, the length of the hamstring muscle before and after the intervention was compared. Results: The results of relaxation exercise of the snake muscles applied to passive PNF group, SMR ball group, and Sling relaxation group are as follows. 1. In the passive PNF group, the muscle length of the hamstring muscle was significantly increased after the intervention. 2. The muscle length of the hamstring muscle was significantly increased after the intervention in the SMR ball group. 3. Sling relaxation group significantly increased the muscle length of the hamstring muscle after sling exercise intervention. 4. Passive PNF group showed the greatest change in muscle length before and after intervention than SMR ball group and Sling relaxation group. Conclusion: Passive PNF relaxation therapy, SMR ball relaxation therapy, and Sling relaxation therapy applied to the hamstring muscle were effective in increasing muscle length of the hamstring muscle. PNF relaxation therapy showed the most significant effect after 3 weeks intervention.

• PNF and Movement
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• 제18권3호
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• pp.375-382
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• 2020

Purpose: The purpose of this study was to investigate the muscle contraction onset time characteristics of the gluteus maximus, semitendinosus, and biceps femoris muscles at different knee flexion angles in individuals with shortened or over-lengthened hamstrings performing prone hip extension. Methods: Twenty-six participants were divided into a hamstring shortened group (n = 12) and hamstring lengthened group (n = 14). Wireless surface electromyography was used to verify the muscle onset time of the gluteus maximus, semitendinosus, and biceps femoris when performing prone hip extension at different knee flexion angles. Results: There were significant differences in the muscle onset times of the semitendinosus and biceps femoris between the hamstring shortened group and hamstring lengthened group (p < 0.05). In addition, there was a significant difference in the muscle contraction onset times among of the gluteus maximus, semitendinosus, and biceps femoris muscles when performing prone hip extension at a knee flexion of 90° in the hamstring shortened group (p < 0.05) and a knee flexion angle of 0° in the hamstring lengthened group (p < 0.05). Conclusion: In all groups, there was no effect on the onset time of the gluteus maximus muscle according based on the knee angle. In addition, the knee flexion angles affected the onset time of the muscle contraction of the gluteus maximus muscle in the hamstring shortened group and hamstring lengthened group with an abnormal length of the hamstring muscle.

• 대한정형도수물리치료학회지
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• 제29권3호
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• pp.1-11
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• 2023

Background: The aim of this study was to compare the effects of squat training on an unstable support surface with different knee flexion angles on the balance ability of normal adults balance ability. Methods: 41 university students in their 20s attending N University in Cheonan, Chungcheongnam-do were divided into a 45-degree knee-bending squat training group and a 90-degree knee-bending squat training group. The groups trained on an unstable support surface 20 minutes per day, 3 times a week, for a total of 4 weeks. Results: Changes in static balance ability were not significant within and between the groups for both the sway distance and sway area in the eyes open and eyes closed states (p<.05). The changes in dynamic balance ability were significant in the forward, leftward, and rightward angles in both groups at the limit of stability (p<.05), but not significant in the backward angle (p>.05), and the comparison between groups was not significant (p>.05). Conclusion: No significant difference between static balance-related variables within and between the groups was found. Significant changes in dynamic balance-related variables within the groups were found but not between the groups. Therefore, in future studies, it is considered necessary to study various ages and differentiated intervention periods, such as young adults and the population of elderly people, with sufficient intervention periods to affect balance ability.

• 대한물리치료과학회지
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• 제31권2호
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• pp.52-62
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• 2024

Background: This study was to investigate effects of narrow squat exercise according to ankle angle of Toe in 10° and Toe out 10° on women with genu varum. Design: Randomized Controlled Trial or Cross-sectional Study. Methods: 30 adult women with genu varum participated in this study. All subjects were randomly assigned to 15 people of narrow squat exercise in ankle angle of Toe in 10° group (TI) and 15 people of narrow squat exercise in ankle angle of Toe out 10° group (TO). The narrow squat exercise program was conducted three times a week for six weeks. The distance between the knees was measured by using Digital Vernier Caliper. The quadriceps angle (Q-angle) was measured by using Goniometer. The stride length and propulsion were measured through G-Walk Results: Both TI and TO groups showed effective significant differences in distance between the knees, Q-angle, and propulsion (p<.05). There was no significant difference in stride length (p>.05). Left leg propulsion was found to be significantly more effective in TI group than in TO group (p<.05). Conclusion: These results suggested that narrow squat exercise according to ankle angle of toe in 10° and toe out 10° was effective for genu varum. However, compared to TO group, TI group was more effective in gait propulsion. It is considered that narrow squat exercise in ankle angle of Toe in 10° can be suggested as an effective intervention method for women with genu varum.