Maximal and explosive force production capacity and balance performance in men of different ages

1999 ◽  
Vol 79 (3) ◽  
pp. 260-267 ◽  
Author(s):  
M. Izquierdo ◽  
X. Aguado ◽  
R. Gonzalez ◽  
J. L. L�pez ◽  
K. H�kkinen
Keyword(s):  
Production Capacity ◽  
Force Production ◽  
Balance Performance ◽  
Different Ages ◽  
Explosive Force

scholarly journals Force production capacity and functional reflex activity in young and elderly men

2010 ◽  
Vol 22 (5-6) ◽  
pp. 374-382 ◽  
Author(s):  
Urs Granacher ◽  
Markus Gruber ◽  
Albert Gollhofer
Keyword(s):  
Production Capacity ◽  
Force Production ◽  
Reflex Activity ◽  
Elderly Men

scholarly journals Effects of Acupuncture on Explosive Force Production by the Healthy Female Shoulder Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
I-Lin Wang ◽  
Yi-Ming Chen ◽  
Jun Wang ◽  
Rui Hu ◽  
Ke-Ke Zhang ◽  
...  
Keyword(s):  
Shoulder Joint ◽  
Force Production ◽  
Maximum Speed ◽  
Maximum Torque ◽  
Shoulder Muscles ◽  
Potentiation Effect ◽  
Average Maximum ◽  
Significant Difference ◽  
Before And After ◽  
Explosive Force

Background. Acupuncture is often used to treat chronic conditions, such as pain. In recent years, given the importance of the explosive forces generated by shoulder muscles for the completion of motor tasks, studies in which nerves were stimulated through acupuncture to increase the explosive forces were conducted. This study explored the effect of acupuncture on explosive force production by the muscles of the female shoulder joint. Methods. Eighteen healthy women underwent shoulder adduction (Add), abduction (Abd), flexion (Flex), and extension (Ext) tests with an isokinetic measurement system. Acupuncture was used to stimulate the Zhongfu (LU1), Tianfu (LI3), Xiabai (LU4), Binao (LI14), Naohui (SJ13), Jianliao (SJ14), and Xiaoluo (SJ12) points, and electromyography (EMG) signals were recorded before and after acupuncture. Results. After acupuncture, there was a significant difference in the average maximum work, the average maximum power, the average maximum speed, the total work in Add/Abd and Flex/Ext, the EMG signals, and the stiffness of the muscles in Abd and Ext ( P < 0.05 ). There were no significant differences in the average maximum torque in Abd or Flex. Conclusion. Based on the results, there may be a significant correlation between the manipulation of different acupoints by acupuncture and the average maximum torque and stiffness. Acupuncture may stimulate nerves to activate muscles and induce a postactivation potentiation effect that improves explosive force production. Therefore, acupuncture as an auxiliary tool may increase the explosive forces generated by acupoint-related muscles by stimulating nerves.

Force-length relation of isometric sarcomeres in fixed-end tetani

1993 ◽  
Vol 264 (1) ◽  
pp. C19-C26 ◽  
Author(s):  
A. Horowitz ◽  
G. H. Pollack
Keyword(s):  
Sarcomere Length ◽  
Production Capacity ◽  
Force Production ◽  
Length Change ◽  
Optical Diffraction ◽  
Tetanic Force ◽  
End Conditions ◽  
Linear Force ◽  
Fixed End

The higher force observed in fixed-end tetani relative to sarcomere-isometric tetani is commonly attributed to sarcomere length inhomogeneity; sarcomeres in the end regions of the fiber shorten extensively at the expense of the central sarcomeres. By shortening, these sarcomeres supposedly attain higher force production capacity and can thus account for the extra force. However, the fibers could also contain sarcomeres that stay isometric throughout most of the tetanic force plateau. If such sarcomeres undergo slight shortening before their isometric phase, their force-length relation should be elevated (A. Horowitz, H. P. M Wussling, and G. H. Pollack. Biophys. J. 63: 3-17, 1992). These sarcomeres may therefore account for the higher force in fixed-end tetani. To test this possibility, single frog semitendinosus fibers were tetanized under fixed-end conditions. Sarcomere length change during the tetanus was measured at different locations along the fiber by optical diffraction. Fibers stretched to average sarcomere lengths between 2.2 and 3.2 microns contained sarcomeres that, except for some initial shortening during the early part of the tetanus, remained isometric. These sarcomeres were located between the ends and the central region of the fibers. Their force-length relation was higher than the linear force-length relation based on sarcomere length clamps by an average of 14% between sarcomere lengths of 2.4-3.2 microns. Thus slight (1-5%) shortening may explain the relatively higher fixed-end force-length relation.

A Dynamic Escape Problem of Molecular Motors

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Dean Culver ◽  
Bryan Glaz ◽  
Samuel Stanton
Keyword(s):  
Molecular Motors ◽  
Binding Sites ◽  
Molecular Motor ◽  
Myosin Ii ◽  
Three Dimensional ◽  
Production Capacity ◽  
Force Production ◽  
Actin Binding ◽  
Three Dimensional Model ◽  
Thermal Agitation

Abstract Animal skeletal muscle exhibits very interesting behavior at near-stall forces (when the muscle is loaded so strongly that it can barely contract). Near this physical limit, the myosin II proteins may be unable to reach advantageous actin binding sites through simple attractive forces. It has been shown that the advantageous utilization of thermal agitation is a likely source for an increased force-production capacity and reach in myosin-V (a processing motor protein), and here we explore the dynamics of a molecular motor without hand-over-hand motion including Brownian motion to show how local elastic energy well boundaries may be overcome. We revisit a spatially two-dimensional mechanical model to illustrate how thermal agitation can be harvested for useful mechanical work in molecular machinery inspired by this biomechanical phenomenon without rate functions or empirically inspired spatial potential functions. Additionally, the model accommodates variable lattice spacing, and it paves the way for a full three-dimensional model of cross-bridge interactions where myosin II may be azimuthally misaligned with actin binding sites. With potential energy sources based entirely on realizable components, this model lends itself to the design of artificial, molecular-scale motors.

Explosive Force Production and Fractionated Reaction Time in Elderly Low and High Active Women

2007 ◽  
Vol 39 (Supplement) ◽  
pp. S105
Author(s):  
Dain P. LaRoche ◽  
Christopher A. Knight ◽  
Jennifer Dickie ◽  
Melanie Lussier ◽  
Stephen Roy
Keyword(s):  
Reaction Time ◽  
Force Production ◽  
Explosive Force

Balance Performance, Force Production, and Activity Levels in Noninstitutionalized Men 60 to 90 Years of Age

1990 ◽  
Vol 70 (6) ◽  
pp. 348-355 ◽  
Author(s):  
Brian D Iverson ◽  
Marilyn R Gossman ◽  
Shirley A Shaddeau ◽  
Malcolm E Turner
Keyword(s):  
Force Production ◽  
Activity Levels ◽  
Balance Performance

Explosive force production during isometric squats correlates with athletic performance in rugby union players

2013 ◽  
Vol 31 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Neale Anthony Tillin ◽  
Matthew Thomas Gerard Pain ◽  
Jonathan Folland
Keyword(s):  
Athletic Performance ◽  
Force Production ◽  
Rugby Union ◽  
Explosive Force
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