• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.203-212
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• 2008

The purpose of this study is to propose appropriate model for 3 staged Didimsae movement to Jajinmori rhythm and to provide information for ideal foot step movements. For the locational change of body center, the height of body center is lowered at the moment of forward step and during forward intersection of the feet, forward direction linear motion is converted to vertical motion to maintain stability. Speed change of body center reduces flow of body on step forward moment and controls rapid forward movement for stabled movement and position when preventing fast forward horizontal direction movement of centroid speed while knee joint and foot joint are vertically risen for heel bone contacts the ground. For angle changes of joints, in order to prevent hyperextension of lower leg, hip joint is extended and knee joint is curved to secure stability of movement for smooth curves and extension. When centroid of foot joint is moved from top of the feet to whole foot sole and when left foot makes dorsal curve, stabled movement is accomplished.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.510-518
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• 2014

In this study, in order to improve and optimize the performance of the turning mechanism for a fish robot in the fluid, we propose the tail joint trajectories using neural networks to mimic the CST(C-shape Sharp Turn) patterns of a real fish which is optimized in the natural environment. In order to mimic the CST patterns of a fish, we convert the sequential recording CST patterns into the coordinate data, and change the numerical coordinate data into a functions. We change the motion functions to the relative joint angles which is adapted to suit robot's shape and data. However, these relative joint trajectories obtained by the sequential recording of the carp have low-precision. It is difficult to apply to the control of a fish robot. Therefore, the relative joint trajectories are interpolated using neural networks with superior generalization ability and applied to the fish robot. we have found that the proposed method using neural networks is superior to ones using high-order polynomial equation through the computer simulations.

• The Journal of the Korea Contents Association
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• v.22 no.8
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• pp.648-659
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• 2022

The purpose of this study is to investigate the effects of Hand Acupressure Therapy on lower back pain, hip joint range of motion, and depression in postpartum women. Methods: Data was collected from March 21 to May 1, 2022 from 40 postpartum women. 𝛘²-test, independent t-test, repeated measures analysis of variance (ANOVA), and Scheffe's test were performed using SPSS/WIN 21.0. Results: Compared with the control group, the lower back pain score of the experimental group that performed Hand Acupressure therapy was lower, and the angle of joint range of motion was increased. Postpartum depression scores were also shown to decrease, and all of these results were statistically significant. Conclusions: Based on this study, it was confirmed that Hand Acupressure therapy can be used as an effective non-invasive intervention for back pain, joint range of motion, and postpartum depression, and suggested the implications and direction of further research.

• Journal of Internet Computing and Services
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• v.14 no.6
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• pp.33-39
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• 2013

When the eldery with limited mobility and disabled use a wheelchairs to move, it can cause decreased exercise ability like decline muscular strength in upper limb and lower extremities. The disabled people suffers with spinal cord injuries or post stroke hemiplegia are easily exposed to secondary problems due to limited mobility. In this paper, We designed intelligent wheelchair robot system for upper limb and lower extremities exercise/rehabilitation considering the characteristics of these severely disabled person. The system consists of an electric wheelchair, biometrics module for Identification characteristics of users, upper limb and lower extremities rehabilitation. In this paper, describes the design and configurations and of developed robot. Also, In order to verify the system function, conduct performance evaluation targeting non-disabled about risk context analysis with biomedical signal change and upper limb and lower extremities rehabilitation over wheelchair robot move. Consequently, it indicate sufficient tracking performance for rehabilitation as at about 86.7% average accuracy for risk context analysis and upper limb angle of 2.5 and lower extremities angle of 2.3 degrees maximum error range of joint angle.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.73-83
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• 2008

The purpose of this study was to investigate kinematic variables of three types of volleyball jump blocking motions through 3D video analysis. The subjects participated in this study were 7 male university volleyball players and 7 male physical education majors. 1. Regardless of blocking types, peak vertical velocity and jump height in the skilled group were faster and higher than the unskilled group. 2. The skilled group was flexed lower than the unskilled group at E2 of the hip, knee, and ankle joint during the cross over step blocking. 3. In all types of step, the peak angular velocity of the hip, knee, and ankle joint was showed at E2. 4. The skilled group was slower than the unskilled group at E2 of the angular velocity of the hip, knee, and ankle joint during cross over step blocking. In conclusion, the cross over step blocking in which the use of the upper extremities was relatively more available was effective to improve a defence skill for the jump height.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.75-80
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• 2005

Purpose : Internal tibial torsion is prevalent in East Asian countries such as Korea and Japan, where sitting on the floor is common behavior. Internal tibial torsion or excessive lateral tibial torsion may cause esthetical, functional, or psychological problems and also may induce degenerative arthritis in older age. The purpose of this study is to measure the tibial torsion in children of the Jeju area. Methods : Tibial torsion was measured in 1,042 lower extremities of 521 children from one to 12 years of age. The values of transmalleolar angles were analyzed for each age group divided by 6 months. Quadratic and linear regression models were used to fit patterns of changes in mean values of transmalleolar angles. The age at seven, which provides the highest coefficient of determination for quadratic regression analysis, was used as a cut-off point to fit different statistical models. Results : The mean transmalleolar angle was $0.10{\pm}5.79^{\circ}$ in all children,$ 0.90{\pm}5.49^{\circ}$ in males, and $-0.80{\pm}5.97^{\circ}$ in females. The value was $4.25{\pm}4.04$ in 1 year of age, gradually decreased to the lowest level of $-1.98^{\circ}$ in four years and seven months of age, increased again with age until it reached $0.67{\pm}1.10^{\circ}$ at seven years of age, and stayed at that level thereafter. Conclusion : Internal tibial torsion in infancy is known to correct spontaneously in the normal developing process. But in this study, the mean transmalleolar angle in children of Jeju area annually decreased after one year of age; to the lowest angle at four years and seven months of age; increased again gradually to the age of seven; and persisted in that level, about $10^{\circ}$ less than western children, not correcting further thereafter. These findings suggest tibial torsion might be caused by lifestyle, especially sitting on feet. To prevent abnormalities of joints and gaits, early diagnosis of tibial torsion in childhood and posture correction or early treatment when needed, seems to be necessary.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.635-645
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• 2015

This study analyzed the range of motion of upper body in different configurations of firefighters' protective clothing and equipment. The purpose of this study was to understand the influence of firefighters' protective clothing and equipment over upper body motion in order to improve design of firefighters' protective clothing and equipment. 12 firefighters' upper body range of motion was analyzed while performing standing and walking trials in five different garment configurations including turnout ensemble, fire boots and the self-contained breathing apparatus. Analysis of upper body range of motion included spinal joints of L5S1, L4L3, T1C7, and C1Head. During standing trials, garment configurations caused a significant difference in range of motions at joints of L5S1, L4L3, T1C7, and C1Head. Analysis on the mean of range of motions at L5S1 and L4L3, showed that firefighters' waist bent forward significantly to a greater extent while they wore a self-contained breathing apparatus. A significantly increased range of motion was found for T1C7 and C1Head while carrying a self-contained breathing apparatus, which indicated an increase in the extension of the trunk and neck backward to stand upright and look squarely. A significant difference in range of motion was also found for L5S1 and L4L3 during walking trials.

• Journal of Broadcast Engineering
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• v.17 no.3
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• pp.447-458
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• 2012

We present a method to recognize hand gestures using skeletal joint data obtained from Microsoft's Kinect sensor. We propose a combination feature of multi-angle histograms robust to orientation variations to represent the observation sequence of skeletons. The proposed feature efficiently represents the orientation variations of gestures that can be occurred according to person or environment by combining the multiple angle histograms with various angular-quantization levels. The gesture represented as combination of multi-angle histograms and random decision forest classifier improve the recognition performance. We conduct the experiments in hand gesture dataset obtained from a kinect sensor and show that our method outperforms the other methods by comparing the recognition performance.

• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.556-563
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• 2015

The purpose of this study was to analyzed body movement of the right and left directions relative to stance width. Seven college students(male, height $174.9{\pm}4.8cm$, weight $70.9{\pm}6.6kg$) participated in this study. For the purpose of this study, nine high-speed cameras and two force plates was utilized. Stance width was limited into small stance width(mean 42.9cm) and large stance width(mean 65cm). The results showed that (1) the small stance width took shorter time than the large stance during landing of the right feet to toe-off; (2) the small stance width was took longer movement of the right feet after split step comparing to the large stance; (3)there was no significant difference in the speed of center of gravity between toe-off and maximum speed; (4) the small stance width was greater angles to hip joint and knee joint during toe-off of the right feet comparing to the large stance; (5) the was no significant difference in values for force plates between the small stance and the large stance width during toe-off of the right feet.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.119-130
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• 2002

The nonlinear finite element program has been developed to analyze the design performance of an artificial hip prosthesis and long term behavior of a treated femur with stems made of composite material after cementless total hip arthroplasty(THA). The authors developed the three dimentional FEM models of femoral bone with designed composite stem which was taken with elliptic cross section of 816 brick elements under hip contact load and muscle farce in simulating single leg stand. Using the program, density changes, stress distributions and micromotions of the material femoral bone were evaluated by changing fiber orientation of stems for selected manufacturing method such as plate cut and bend mold. The results showed that the composite materials such as AS4/PEEK and T300/976 gave less bone resorption than the metallic material such as cobalt chrome alloy, titanium alloy and stainless steal. It was found that increasing the long term stability of the prosthesis in the femur could be obtained by selecting the appropriate ply orientation and stacking sequence of composite.