• Title/Summary/Keyword: Ground reaction force

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A study of the effect of walking speed upon gait parameters and foot-ground reaction forces (보행속도가 보행특성모수 및 지면반발력에 미치는 영향에 관한 연구)

  • 황규성;정민근;이동춘
    • Journal of the Ergonomics Society of Korea
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    • v.11 no.1
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    • pp.93-101
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    • 1992
  • Gait parameters for the Korean normal adults were compared with sex and age. Time-distance measurements and ground reaction force parameters were studied in relation to walking speed. Regression analysis was performed to establish functional relations between walking speed and various gait parameters. It is found that cardence and stride length varied linearly with walking velocity whereas time of double support was inversely proportional to walking velocity. The amplitude of ground reaction force was increased with increasing velocities of gait due to the greater heel-strike force and toe-off forces associated with these higher velocities. The results of this study can be usefull utilized as basic data to design and evaluate prosthetic devices, and to detect abnormal gait performances.

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Hybrid Position/Force Control for Dynamic Walking of Biped Walking Robot (이족보행로봇의 동적 보행을 위한 혼합 위치/힘 제어)

  • 박인규;김진걸
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.05a
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    • pp.566-569
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    • 2000
  • This hybrid position/force control for the dynamic walking of the biped robot is performed in this paper. After the biped robot was modeled with 14 degrees of freedom of the multibody dynamics, the equations of motion are constructed using velocity transformation technique. Then the inverse dynamic analysis is performed for determining the driving torques and the ground reaction forces. From this analysis, obtains the maximum ground contact force at the moment of contacting which act on the rear of the sole of swing leg and the distribution curve of the ground reaction. Because these maximum force and distribution type acts an important role to the stability of the whole dynamic walking, they are reduced and distributed smoothly by means of the trajectory of the modified ground reaction force. This new trajectory is used to the reference input for more stable dynamic walking of the whole walking region.

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Analysis of Stability on Single-leg Standing by Wearing a Head Mounted Display

  • Woo, Byung Hoon
    • Korean Journal of Sport Biomechanics
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    • v.27 no.2
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    • pp.149-155
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    • 2017
  • Objective: The purpose of this study was to investigate the effects of three visual conditions (eyes opened, eyes closed, and wearing of a head mounted display [HMD]) on single-leg standing through kinematics and kinetic analysis. Method: Twelve college students (age: $24.5{\pm}2.6years$, height: $175.0{\pm}6.4cm$, weight: $69.2{\pm}5.1kg$) participated in this study. The study method adopted three-dimensional analysis with six cameras and ground reaction force measurement with one force plate. The analysis variables were coefficient of variation (CV) of the center of body mass, head movement, ground reaction force, and center of pressure, which were analyzed using one-way analysis of variance with repeated measures according to visual conditions. Results: In most cases, the results of this study showed that the CV was significantly higher in the order of HMD wearing, eyes closed, and eyes opened conditions. Conclusion: Our results indicated that body sway was the largest in the HMD wearing condition, and the risk of falling was high owing to the low stability.

Motor noise removal for determining gait events over treadmill walking using wavelet filter

  • Yeom, Ho-Jun;Selgrade, Brian P.;Chang, Young-Hui;Kim, Jung-Lae
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.48-51
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    • 2012
  • The conventional method for filtering force plate data, low-pass filtering, does not always give accurate results when applied to force data from a custom-made, instrumented treadmill. Therefore, this study compares low-pass filtered data to the same data passed through a wavelet filter. We collected data with the treadmill running. However these include motor noise with ground reaction force at two force plates. We found that he proposed wavelet method eliminated motor noise to result in more accurate force plate data than the conventional low-pass filter, particularly at high speed motor operation. In this study we suggested the convolution wavelet (CNW) which was compared to that of a low-pass filter. The CNW showed better performance as compared to band-pass filtering particularly for low signal-to-noise ratios, and a lower computational load.

Effects of Task-Oriented Circuit Class Training on Improves Performance of Locomotor in Disabled Persons after Stroke (과제-지향 순회 훈련이 뇌졸중 장애인의 이동 능력에 미치는 효과)

  • Kim, Soo-Min
    • Journal of the Korean Society of Physical Medicine
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    • v.6 no.4
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    • pp.447-454
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    • 2011
  • Purpose : The purpose of this study was to identify the effects of circuit class training on the performance of locomotor tasks in chronic stroke. Methods : The study included 45 patients with chronic stroke randomly divided into experimetal group and control group. Both groups participated in exercise classes three times a week for 8weeks. The experimental group had 10 workstation of circuit class designed to improve walking. The control group practiced fitness exercises by equipment in health center. Walking performance was assessed by measuring walking speed(timed 10-meter walk and TUG), GAITRite analysis and peak vertical ground reaction force through the affected foot during walking. Results : The experimental group demonstrated significant improvement(p<.05) compared with the control group in 10-meter walking and vertical ground reaction force after training. The experimental group showed significant improvements in the walking velocity and cadence by GAITRite system(p<.05). Conclusion : Task- oriented circuit class training leads to improvements in locomotor function in chronic stroke. Further studies are necessary to occur in usual environments to improve walking performance.

The Benefits of Stick Walking: Evaluation at Ankle, Knee and Hip Joints

  • Kim, Suk-Won;Lee, Jung-Yong;Park, Ki-Won;Yoon, Hoon-Yong;Park, Sung-Ha
    • Journal of the Ergonomics Society of Korea
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    • v.24 no.4
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    • pp.63-71
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    • 2005
  • A laboratory study was performed to evaluate the effects of an aid(i.e. stick) on joint loadings. Six healthy young participants were recruited from Virginia Tech student population. Each participant has performed three normal walking and three stick walking trials. Normalized and integrated, ground reaction forces(GRFs) and joint moments were measured at ankle, knee, and hip joints from kinematic and kinetic data. The result suggests that stick walking significantly reduces vertical ground reaction force and joint moments at ankle and knee compared to normal walking.

Numerical study on the walking load based on inverted-pendulum model

  • Cao, Liang;Liu, Jiepeng;Zhang, Xiaolin;Chen, Y. Frank
    • Structural Engineering and Mechanics
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    • v.71 no.3
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    • pp.245-255
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    • 2019
  • In this paper, an inverted-pendulum model consisting of a point supported by spring limbs with roller feet is adopted to simulate human walking load. To establish the kinematic motion of first and second single and double support phases, the Lagrangian variation method was used. Given a set of model parameters, desired walking speed and initial states, the Newmark-${\beta}$ method was used to solve the above kinematic motion for studying the effects of roller radius, stiffness, impact angle, walking speed, and step length on the ground reaction force, energy transfer, and height of center of mass transfer. The numerical simulation results show that the inverted-pendulum model for walking is conservative as there is no change in total energy and the duration time of double support phase is 50-70% of total time. Based on the numerical analysis, a dynamic load factor ${\alpha}_{wi}$ is proposed for the traditional walking load model.