Mechanisms of Posture Maintenance in Weightlessness

2015 ◽  
pp. 158-163 ◽  
Author(s):  
G. Cl�ment ◽  
V. S. Gurfinkel ◽  
F. Lestienne
Keyword(s):  
Posture Maintenance

scholarly journals Research on the Posture Control Method of Hexapod Robot for Rugged Terrain

2020 ◽  
Vol 10 (19) ◽  
pp. 6725
Author(s):  
Yubin Liu ◽  
Chunbo Wang ◽  
He Zhang ◽  
Jie Zhao
Keyword(s):  
Control Method ◽  
Posture Control ◽  
Rough Terrain ◽  
Maintenance Strategy ◽  
Hexapod Robot ◽  
Rugged Terrain ◽  
Foot Force ◽  
Adjustment Strategy ◽  
Posture Maintenance ◽  
Posture Adjustment

This paper proposes a hexapod robot posture control method for rugged terrain to solve the problem of difficulty in realizing the posture control of a foot robot in rough terrain. The walking gait and original position of a six-legged robot is planned, and the Layer Identification of Tracking (LIT) strategy is developed to enable the robot to distinguish mild rugged terrain and severe rugged terrains automatically. The virtual suspension dynamic model is established. In mild rugged terrain, the posture maintenance strategy is adopted to keep the stability of the torso. In severe rugged terrain, the posture adjustment strategy is adopted to ensure the leg workspace and make it more widely adapt to the changing terrain, and a gravity center position adjustment method based on foot force distribution is designed to use foot force as feedback to control the position and attitude. The experiment of posture control in rough terrain and climbing experiment in the ladder terrain shows that the hexapod robot has good posture maintenance and posture adjustment effects when traversing complex terrain through the posture maintenance strategy and the posture adjustment strategy. Combined with the terrain identification method based on LIT, the hexapod robot can successfully climb the ladder terrain through the identification of the changing ladder terrain, and the movement of the posture adjustment process is stable.

Analysis of the reflexive feedback control loop during posture maintenance

2001 ◽  
Vol 84 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Erwin de Vlugt ◽  
Frans C. T. van der Helm ◽  
Alfred C. Schouten ◽  
Guido G. Brouwn
Keyword(s):  
Feedback Control ◽  
Control Loop ◽  
Posture Maintenance

A Power Assist Device Based on Joint Equilibrium Point Estimation from EMG Signals

2012 ◽  
Vol 24 (1) ◽  
pp. 205-218 ◽  
Author(s):  
Toshihiro Kawase ◽  
◽  
Hiroyuki Kambara ◽  
Yasuharu Koike ◽  
Keyword(s):  
Equilibrium Point ◽  
Equilibrium Points ◽  
User Equilibrium ◽  
Point Estimation ◽  
Joint Torque ◽  
Stable Operation ◽  
Assist Devices ◽  
User Intentions ◽  
Torque Estimation ◽  
Posture Maintenance

In some researches about power assist devices, surface ElectroMyoGraphy (EMG) signals are used to estimate user intentions to move their limbs. These conventional methods mainly focus on estimation of joint torque. However, the devices based on torque estimation are inclined to cause the vibration of users’ posture originating from the waviness of the EMG signals. Focusing on estimation of states related to the joint angle may improve the performance of the power assist devices. This paper proposes a new method that estimates user joint equilibrium point and stiffness separately from the EMG and that amplifies the stiffness while tuning the device joints according to user equilibrium points. To evaluate the method, we constructed a power assist system for the wrist and compared the method with a method based on simple torque estimation during posture maintenance tasks. Our results showed that the proposed method offers a more stable operation at the same assist ratio and proved the effectiveness of the method.

scholarly journals Influence of environmental stability on the regulation of end-point impedance during the maintenance of arm posture

2013 ◽  
Vol 109 (4) ◽  
pp. 1045-1054 ◽  
Author(s):  
Matthew A. Krutky ◽  
Randy D. Trumbower ◽  
Eric J. Perreault
Keyword(s):  
Fundamental Difference ◽  
Environmental Stability ◽  
Static Component ◽  
End Point ◽  
Stiffness Properties ◽  
Postural Tasks ◽  
Posture Maintenance ◽  
Selective Increase

Many common tasks compromise arm stability along specific directions. Such tasks can be completed only if the impedance of the arm is sufficient to compensate for the destabilizing effects of the task. During movement, it has been demonstrated that the direction of maximal arm stiffness, the static component of impedance, can be preferentially increased to compensate for directionally unstable environments. In contrast, numerous studies have shown that such control is not possible during postural tasks. It remains unknown if these findings represent a fundamental difference in the control of arm mechanics during posture and movement or an involuntary response to the destabilizing environments used in the movement studies but not yet tested during posture maintenance. Our goal was to quantify how arm impedance is adapted during postural tasks that compromise stability along specific directions. Our results demonstrate that impedance can be modulated to compensate for these instabilities during postural tasks but that the changes are modest relative to those previously reported during reaching. Our observed changes were primarily in the magnitude of end-point stiffness, but these were not sufficient to alter the direction of maximal stiffness. Furthermore, there were no substantial changes in the magnitude of end-point viscosity or inertia, suggesting that the primary change to arm impedance was a selective increase in stiffness to compensate for the destabilizing stiffness properties of the environment. We suggest that these modest changes provide an initial involuntary response to destabilizing environments prior to the larger changes that can be affected through voluntary interventions.

scholarly journals Applying the Theory of Planned Behavior to Correct Posture in Operating Room Staffs

2016 ◽  
Vol 9 (4) ◽  
pp. 122
Author(s):  
Ahmad Fakhri ◽  
Isa Mohammadi Zeidi ◽  
Hadi Morshedi
Keyword(s):  
Theory Of Planned Behavior ◽  
Operating Room ◽  
Planned Behavior ◽  
Behavioral Control ◽  
Demographic Data ◽  
Perceived Behavioral Control ◽  
Actual Behavior ◽  
Work Related ◽  
Posture Maintenance ◽  
Health Promotion Interventions

<p><strong>OBJECTIVE</strong><strong>: </strong>Ergonomic risk factors such as prolonged and awkward postures increase the risk of work related musculoskeletal disorders (WRMSDs) in operating room staffs. Understanding the factors influencing the prevalence of the WRMSDs is an essential step in any targeted health promotion interventions. This research aimed to determine the factors associated with correct posture maintenance based on the theory of planned behavior (TPB) among the operating room staffs from educational hospital affiliated to Qazvin university medical sciences, in 2013.</p><p><strong>METHODS</strong><strong>: </strong>A total of 130 subjects with mean ages of 31.2±6.38 years participated in this study. Demographic data and TPB constructs were assessed using reliable and valid scales. Path analysis, based on TPB components, was applied to determine specific factors that most contribute to and predict actual behavior toward correct posture maintenance.</p><p><strong>RESULTS</strong><strong>: </strong>Psychometric properties of the model were consistent with the recommendations and results showed that variables were fit to the data. 58% of the variance in behavioral intention (BI) was described by the TPB constructs (P&lt;0.05). Also, attitude (AT), subjective norms (SN), perceived behavioral control (PBC) and BI explained 39% of the variance in maintenance of a correct posture (P&lt;0.05). Consistent with<strong> </strong>predictions from the TPB, AT (β<sub>i</sub>=0.44, P&lt;0.05) were the major predictors of BI. In addition, PBC (β<sub>i</sub>=0.52, P&lt;0.05) and BI (β<sub>i</sub>=0.41, P&lt;0.05) were the important factors that influence the maintenance of a correct posture in the operating room staffs.</p><p><strong>CONCLUSION</strong><strong>: </strong>As a conclusion, TPB is a useful model to determine and to predict maintenance of a correct posture in the operating room staffs.</p>

The Size of the Visual Feedback-Providing Object Affects the Vertical Posture Maintenance in Humans

2020 ◽  
Vol 46 (6) ◽  
pp. 677-688
Author(s):  
B. N. Smetanin ◽  
Yu. S. Levik ◽  
G. V. Kozhina ◽  
A. K. Popov
Keyword(s):  
Visual Feedback ◽  
Vertical Posture ◽  
Posture Maintenance

Obesity effect on perceived postural stress during static posture maintenance tasks

Ergonomics ◽  
2009 ◽  
Vol 52 (9) ◽  
pp. 1169-1182 ◽  
Author(s):  
Woojin Park ◽  
Devender P. Singh ◽  
Martin S. Levy ◽  
Eui S. Jung
Keyword(s):  
Postural Stress ◽  
Posture Maintenance
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