EMG and force response to sinusoidal movement of normal and spastic ankles

1983 ◽  
Vol 56 (3) ◽  
pp. S184
Author(s):  
A.F Thilmann ◽  
P.M.H. Rack ◽  
H.F. Ross
Keyword(s):  
Force Response ◽  
Sinusoidal Movement

scholarly journals Morbidity among the Israeli Defense Force response team during Nepal, post-earthquake mission, 2015

2017 ◽  
Vol 24 (2) ◽  
Author(s):  
Tamar Lachish ◽  
Aviad Bar ◽  
Heli Alalouf ◽  
Ofer Merin ◽  
Eli Schwartz
Keyword(s):  
Force Response ◽  
Israeli Defense Force ◽  
Response Team

Vibration Analysis of a Screw Pump Unit

2013 ◽  
Vol 753-755 ◽  
pp. 1727-1730
Author(s):  
Yue Zhang ◽  
You Hong Xiao ◽  
Jun Weng ◽  
Wan You Li
Keyword(s):  
Mathematical Method ◽  
Vibration Analysis ◽  
Vibration Spectrum ◽  
Vibration Response ◽  
Fe Model ◽  
Force Response ◽  
Pump Unit ◽  
Surface Integral ◽  
Screw Pump

In this paper, the vibration of a three screw pump was studied. Firstly the vibration response of the pump was tested. Then the FE model of the pump was constructed and the modals of it were calculated. The exactness of the result was confirmed by the testing modals and the reasonable of the FE model was verified at the same time. Finally, the force acted on rotors due to pressure was calculated by the mathematical method of surface integral. The force was loaded on the FE model and the force response was predicted, which represented the basic vibration of the screw pump. Based on the work above, the vibration spectrum of the screw pump was analyzed.

scholarly journals Reduced Stretch-Induced Force Response in Failing Human Myocardium Caused by Impaired Na+-Contraction Coupling

2009 ◽  
Vol 2 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Dirk von Lewinski ◽  
Jens Kockskämper ◽  
Danan Zhu ◽  
Heiner Post ◽  
Andreas Elgner ◽  
...  
Keyword(s):  
Human Myocardium ◽  
Force Response ◽  
Contraction Coupling

EFFICIENCY OF ENERGY CONVERSION DURING SINUSOIDAL MOVEMENT OF WHITE MUSCLE FIBRES FROM THE DOGFISH SCYLIORHINUS CANICULA

1993 ◽  
Vol 183 (1) ◽  
pp. 137-147 ◽  
Author(s):  
N. A. Curtin ◽  
R. C. Woledge
Keyword(s):  
Power Output ◽  
High Efficiency ◽  
Fibre Length ◽  
Dry Mass ◽  
Energy Output ◽  
Maximum Efficiency ◽  
Muscle Fibres ◽  
Work Output ◽  
Sinusoidal Movement ◽  
Myotomal Muscle

Net work output and heat production of white myotomal muscle fibres from the dogfish were measured during complete cycles of sinusoidal movement at 12°C. The peak-to-peak movement was about 9 % of the muscle fibre length; three stimuli at 32 ms intervals were given in each mechanical cycle. The frequency of movement and the timing of the stimulation were varied for each preparation to find the optimal conditions for power output and those optimal for efficiency (the ratio of net work output to total energy output as heat+work). To achieve either maximum power or maximum efficiency, the tetanus must start while the muscle fibres are being stretched, before the beginning of the shortening part of the mechanical cycle. The highest power output, averaged over one cycle, was 0.23+/−0.014 W g-1 dry mass (+/−s.e.m., N=9, 46.9+/−2.8 mW g-1 wet mass) and was produced during movement at 3.5 Hz. The highest efficiency, 0.41+/−0.02 (+/−s.e.m., N=13), occurred during movements at 2.0-2.5 Hz. This value is higher than the efficiency previously measured during isovelocity shortening of these fibres. The implications of the high efficiency for crossbridge models of muscle contraction are discussed.

Theoretical and Experimental Study of the Nonlinearly Coupled Heave, Pitch, and Roll Motions of a Ship in Longitudinal Waves

1993 ◽  
Author(s):  
I. G. Oh ◽  
A. H. Nayfeh ◽  
D. T. Mook
Keyword(s):  
Large Amplitude ◽  
Degrees Of Freedom ◽  
Excitation Frequency ◽  
Force Response ◽  
Governing Equations ◽  
Response Curves ◽  
Varying Coefficients ◽  
Jump Phenomena ◽  
Time Varying Coefficients ◽  
Three Degrees Of Freedom

Abstract The loss of dynamic stability and the resulting large-amplitude roll of a vessel in a head or following sea were studied theoretically and experimentally. A ship model with three degrees of freedom (roll, pitch, heave) was considered. The governing equations for the heave and pitch modes were linearized and their harmonic solutions were coupled with the nonlinear equation governing roll. The resulting equation, which has time-varying coefficients, was used to predict the response in roll. The principal parametric resonance was considered in which the excitation frequency is twice the natural frequency in roll. Force-response curves were obtained. The existence of jump phenomena and multiple stable solutions for the case of subcritical instability was observed in the experiments and found to be in good qualitative agreement with the results predicted by the theory. The experiments also revealed that the large-amplitude roll is dependent on the location of the model in the standing waves.

scholarly journals A phenomenological model that predicts forces generated when electrical stimulation is superimposed on submaximal volitional contractions

2010 ◽  
Vol 108 (6) ◽  
pp. 1595-1604 ◽  
Author(s):  
Ramu Perumal ◽  
Anthony S. Wexler ◽  
Trisha M. Kesar ◽  
Angela Jancosko ◽  
Yocheved Laufer ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Intraclass Correlation ◽  
Total Force ◽  
Force Response ◽  
Wide Range ◽  
Central Nervous System Impairment ◽  
Voluntary Contractions ◽  
Functional Movements ◽  
Improve Muscle Strength ◽  
Quadriceps Femoris Muscles

Superimposition of electrical stimulation during voluntary contractions is used to produce functional movements in individuals with central nervous system impairment, to evaluate the ability to activate a muscle, to characterize the nature of fatigue, and to improve muscle strength during postsurgical rehabilitation. Currently, the manner in which voluntary contractions and electrically elicited forces summate is not well understood. The objective of the present study is to develop a model that predicts the forces obtained when electrical stimulation is superimposed on a volitional contraction. Quadriceps femoris muscles of 12 able-bodied subjects were tested. Our results showed that the total force produced when electrical stimulation was superimposed during a volitional contraction could be modeled by the equation T = V + S[(MaxForce − V)/MaxForce]N, where T is the total force produced, V is the force in response to volitional contraction alone, S is the force response to the electrical stimulation alone, MaxForce is the maximum force-generating ability of the muscle, and N is a parameter that we posit depends on the differences in the motor unit recruitment order and firing rates between volitional and electrically elicited contractions. In addition, our results showed that the model predicted accurately (intraclass correlation coefficient ≥0.97) the total force in response to a wide range of stimulation intensities and frequencies superimposed on a wide range of volitional contraction levels. Thus the model will be helpful to clinicians and scientists to predict the amount of stimulation needed to produce the targeted force levels in individuals with partial paralysis.

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