Variable Series Elasticity Control of a Pneumatically Actuated Transtibial Prosthesis1

2016 ◽  
Vol 10 (3) ◽  
Author(s):  
Hao Zheng ◽  
Molei Wu ◽  
Xiangrong Shen
Keyword(s):  
Series Elasticity

Series elasticity of urinary bladder smooth muscle

1976 ◽  
Vol 231 (5) ◽  
pp. 1337-1342 ◽  
Author(s):  
RS Alexander
Keyword(s):  
Elastic Stiffness ◽  
Bladder Smooth Muscle ◽  
Bladder Tissue ◽  
Series Elasticity ◽  
Quick Release ◽  
Contractile System ◽  
Urinary Bladder Smooth Muscle ◽  
In Series ◽  
A Minor

Loops of rat bladder were stretched between pins in vitro, supported by a clamp that could be suddenly shortened by activation of a solenoid to achieve a quick release of tension. The series elasticity measured in this fashion was found to follow an exponential course and to be modified by the rate of release, indicating a minor viscous component. Tissue length decreased and series elastic stiffness appeared to increase with muscle contraction, but no alteration in series elasticity was evident when the data were related to the tension existing in the tissue at the moment of quick release. Inactivation of the contractile system by removing calcium ion with ethylene glycol-bis-(beta-aminoethylether)-N,N'-tetraacetate (EGTA) similarly did not alter series elasticity when it was related to the tension existing in the tissue. Series elasticity during the stress relaxation following a stretch, and during the contracting and relaxing phases of rhythmic contractions, was also determined by tissue tension. The conclusion drawn is that contractile cross bridges do not contribute to the series elasticity measured in bladder tissue.

Effects of Series Elasticity on the Human Knee Extension Torque-Angle Relationship in Vivo

2006 ◽  
Vol 77 (4) ◽  
pp. 408-416 ◽  
Author(s):  
Keitaro Kubo ◽  
Kazuya Ohgo ◽  
Ryuichi Takeishi ◽  
Kazunari Yoshinaga ◽  
Naoya Tsunoda ◽  
...  
Keyword(s):  
Knee Extension ◽  
Human Knee ◽  
Series Elasticity ◽  
Torque Angle

Effect of series elasticity on delay in development of tension relative to stiffness during muscle activation

1994 ◽  
Vol 267 (6) ◽  
pp. C1598-C1606 ◽  
Author(s):  
Y. Luo ◽  
R. Cooke ◽  
E. Pate
Keyword(s):  
Elastic Element ◽  
Muscle Activation ◽  
Muscle Length ◽  
Mechanical Stiffness ◽  
Tension Development ◽  
Series Elasticity ◽  
Series Elastic Element ◽  
Bridge Model ◽  
Elastic Strains ◽  
Series Elastic

Experimental data have indicated that during activation, the attachment of myosin to actin, measured by mechanical stiffness, precedes tension generation by 10-30 ms. Using computer simulation, we have investigated the effect of a series elastic element on the lag between stiffness and tension development during muscle activation. Two versions of the two-state cross-bridge model originally proposed by Huxley and a three-state model were considered. After simulated activation, stiffness and tension increased with rates that were strongly dependent on the series elastic strain. In the absence of a series elastic element, the rise in stiffness preceded, lagged, or was coincident with the increase in tension, depending on the model. For large elastic strains, tension lagged stiffness for all models. Lags of 10-30 ms could be obtained with elastic strains of 0.3-1% of the muscle length. This is a realistic value in experiments without sarcomere length servocontrol, suggesting that series elasticity may be an important contributor to the experimentally observed lag between tension and stiffness.

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