• 한국운동역학회지
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• 제17권3호
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• pp.181-188
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• 2007

The purpose of this study was to investigate the biomechanical effects of wearing different type of insole shoes on gait characteristics in patients with knee osteoarthritis. Seven patients with knee osteoarthritis (Grade 3 & 4 by Kellgren & Lawrence) were participated in the study. They wore two different type of shoes (with Gel-type Insole: GIS, with Normal insole: NIS) during gait. Three dimensional cinematography and Ground Reaction Force(GRF) data were used to get the maximal value of horizontal distance between the center of pressure in GRF and knee joint center, GRF in mediolateral direction, peak value of GRF in frontal plane, vertical compressive force and adduction moment in knee joint. The results were as follows: The maximal value of horizontal distance between the center of pressure in GRF and knee joint center was smaller in GIS than NIS. The peak value of GRF in mediolateral direction was found in 30% of gait cycle, five subjects wearing GIS showed lower value of peak GRF in mediolateral direction than wearing NIS. The peak value of GRF in frontal plane and vertical compressive force in knee joint did not show any difference between GIS and NIS. The adduction moment in GIS decreased in the late stance of gait and the mean value of the adduction moment in GIS smaller than that in NIS. GIS may help to move quickly knee joint center to the center of pressure in GRF, therefore it may prevent increasing the adduction moment in knee joint.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.486-489
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• 2003

To reduce lateral force of traditional plunger type piston in the swash plate type hydraulic piston pumps and motors, we have proposed rod type piston with ball joint on both ends. We have studied the theoretical reaction force on two types of piston moving in the cylinder block bore. and made an experiment for the resistance force measurement on a reciprocating motion of plunger and rod type piston, changing the test condition such as swash plate angel and supply oil pressure and so on. As a result. a rod type piston has more smaller resistance force, about 29%. than a plunger type one.

• 한국운동역학회지
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• 제21권3호
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• pp.383-390
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• 2011

In this study, 26 normal subjects were studied to compare the biomechanical Analysis of Lower Limbs on Speed of Nordic Walking. The biomechanical variables were determined by performing three-dimensional gait analysis, and the measurements items were spatial and temporal parameters; vertical ground reaction force; and moments of the hip, knee, and ankle joints. The purpose of this study based on the speed of Nordic Walking to the vertical ground reaction force and joint moments of each were analyzed. Nordic Walking with poles while being whether this weight is reduced to load, not the improvement of muscle activity by identify Nordic walking is to allow efficient. The results of the analysis were follows. The spatial parameters of step length, stride length significantly increased with increase in velocity(p<0.001). The temporal parameters of step time, stride time, the duration of double support use, and the duration of single support use also significantly decreased with increase in velocity(p<0.001), but cadence significantly increased(p<0.01). Analysis of the changes in ground reaction force revealed that vertical ground reaction force significantly increased at the initial contact and the terminal stance and decreased at the mid stance with increase in velocity(p<0.001). Moments of the hip and knee joints significantly in creased with increase in velocity whereas that of the ankle joint did not. Gait analysis revealed that weight-bearing decreased and moments of the hip and knee joints increased with increase in velocity(p<0.01). The results of this study may help people perform Nordic walking efficiently and Nordic walking can be used in the gait training of people with an abnormal gait.

• 한국운동역학회지
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• 제26권4호
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• pp.413-420
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• 2016

Objective: The purpose of this study was to analyze and compare different kinds of outdoor walking shoes in terms of muscle fatigue and ground reaction force on walking, and to provide foundational data for developing and choosing outdoor walking shoes that fit the users. Method: The study subjects were 30 healthy men. The experiment was conducted by using outdoor walking shoes with different inner and outer harnesses of the midsole, and shapes of the outsole. For data collection, electromyography was used to measure the muscle fatigue of the anterior tibial muscle and gastrocnemii, which contribute to the dorsiflexion and plantarflexion of the ankle joint, and the biceps muscle of the thigh and lateral great muscles, which contribute to the flexion and extension of the knee joint. A GRF measurement device was used to measure the X, Y, and Z axes. Results: In the type A outdoor walking shoes, regarding the hardness of the midsole, the inner part was soft, while the outer part was hard. The vertical ground reaction force was the lowest, which means least impact while walking and light load to the knees and ankles. The type C outdoor walking shoes were intended to provide a good feel in wearing the shoes. The tibialis anterior, biceps femoris, and gastrocnemii indicate low fatigue, which means that during a long-distance walk, it will minimize the fatigue in the muscles of the lower limbs. Conclusion: To sum up the study results, the different types of outdoor walking shoes indicate their unique characteristics in the biomechanical comparison and analysis. However, the difference was not statistically significant. Thus, a systematic and constant follow-up research should be conducted to cope with expanding market for outdoor walking shoes. Lastly, this study is expected to present foundational data and directions for developing outdoor walking shoes.

• 대한기계학회논문집
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• 제18권8호
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• pp.2101-2112
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• 1994

A two-dimensional biomechanical model was developed in order to calculated the lower extremity kinematics and kinetics during level walking. This model consists of three segments : the thigh, calf, and foot. Each segment was assumed to be a rigid body ; its motion to be planar in the sagittal plane. Five young males were involved in the gait experiment and their anthropometric data were measured for the calculation of segmental masses and moments of inertial. Six markers were used to obtain the kinematic data of the right lower extremity for at least three trials of walking at 1.0m/s, and simultaneously a Kistler force plate was used to obtain the foot-floor reaction data. Based on the experimental data acquired for the stance phase of the right foot, calculated vertical joint forces reached up to 0.91, 1.05, and 1.11 BW(body weight) at the hip, the knee, the ankle joints, respectively. The flexion-extension moments reached up to 69.7, 52.3, and 98.8 Nm in magnitude at the corresponding three joints. It was found that the calculated joint loadings of a subject were statistically the same for all his three trials, but not the same for all five subjects involved in the gait study.

• 한국운동역학회지
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• 제34권2호
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• pp.81-92
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• 2024

Objective: The purpose of this study was to analyze the impact acceleration, shock attenuation and biomechanical variables at various running speed. Method: 20 subjects (height: 176.15 ± 0.63 cm, weight: 70.95 ± 9.77 kg, age: 27.00 ± 4.65 yrs.) participated in this study. The subjects ran at four different speeds (2.5 m/s, 3.0 m/s, 3.5 m/s, 4.0 m/s). Three-dimensional accelerometers were attached to the distal tibia, sternum and head. Gait parameters, biomechanical variables (lower extremity joint angle, moment, power and ground reaction force) and acceleration variables (impact acceleration, shock attenuation) were calculated during the stance phase of the running. Repeated measures ANOVA was used with an alpha level of .05. Results: In gait parameters, decreased stance time, increasing stride length and stride frequency with increasing running speed. And at swing time 2.5 m/s and 4.0 m/s was decreased compared to 3.0 m/s and 3.5 m/s. Biomechanical variables statistically increased with increasing running speed except knee joint ROM, maximum ankle dorsiflexion moment, and maximum hip flexion moment. In acceleration variables as the running speed increased (2.5 m/s to 4.0 m/s), the impact acceleration on the distal tibia increased by more than twice, while the sternum and head increased by approximately 1.1 and 1.2 times, respectively. And shock attenuation (tibia to head) increased as the running speed increased. Conclusion: When running speed increases, the magnitude and increasing rate of sternum and head acceleration are lower compared to the proximal tibia, while shock attenuation increases. This suggests that limiting trunk movement and increasing lower limb movement effectively reduce impact from increased shock. However, to fully understand the body's mechanism for reducing shock, further studies are needed with accelerometers attached to more segments to examine their relationship with kinematic variables.

• 대한기계학회논문집A
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• 제22권3호
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• pp.704-713
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• 1998

The analysis of dynamic forces is essential to the design of systems, stress analysis, or life prediction of part of machine. Calculation of dynamic forces has very close relations with multibody dynamics algorithm. In this paper, an algorithm which calculates joint reaction force/moment of flexible multibody dynamic systems is proposed by using inverse dynamic algorithm and velocity transformation technique.

• 한국정밀공학회지
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• 제15권1호
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• pp.160-168
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• 1998

In this paper. the Joint reaction forces in the suspension system of a passenger car are determined to calculate the deflections and stresses in the damper strut. A mathematical model of the Roll Stabilizer Bar(RSB) is developed to include the RSB forces in the dynamics analysis. Using these RSB forces, the variations of the damper forces and spring forces due to the wheel strokes are determined in a McPherson strut suspension. The graphs of shear force diagram, bending moment diagram, bending stress and deflections are drawn by the calculated joint reaction forces.

• 한국정밀공학회지
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• 제21권1호
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• pp.197-204
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• 2004

In this study we presented kinematic and kinetic data of foot joints using approximated equations and partial plantar pressure during gait. The maximum angular displacements of each tarsometatarsal joint were found to range from 4$^{\circ}$to 7$^{\circ}$ and the maximum moments were from 200Nㆍcm to 1500Nㆍcm. It was relatively wide distribution. Foot kinematic data calculated from the approximated equations, which were represented by the correlation between moment and angular displacement, and the data from motion analysis were similar. We found that the movements of foot joint were mainly decided by the passive characteristics of the joint when ground reaction force acts. The method of kinematic and kinetic analysis using approximated equations which is presented in this study is considered useful to describe the movements of foot joints in gait simulations.

• 제어로봇시스템학회논문지
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• 제18권7호
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• pp.644-649
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• 2012

This paper proposes the gait phase classifier using backpropagation neural networks method which uses the angle of lower body's joints and ground reaction force as input signals. The classification of a gait phase is useful to understand the gait characteristics of pathologic gait and to control the gait rehabilitation systems. The classifier categorizes a gait cycle as 7 phases which are commonly used to classify the sub-phases of the gait in the literature. We verify the efficiency of the proposed method through experiments.