Development of force-velocity relation and rise of isometric tetanic tension measure the time course of different processes

1984 ◽  
Vol 401 (4) ◽  
pp. 396-401 ◽  
Author(s):  
G. Cecchi ◽  
V. Lombardi ◽  
G. Menchetti
Keyword(s):  
Time Course ◽  
Velocity Relation ◽  
Force Velocity ◽  
Tetanic Tension

scholarly journals Contraction Dynamics of Flight and Stridulatory Muscles of Tettigoniid Insects

1984 ◽  
Vol 108 (1) ◽  
pp. 77-96 ◽  
Author(s):  
ROBERT K. JOSEPHSON
Keyword(s):  
Isometric Contraction ◽  
Time Course ◽  
Published Data ◽  
Shortening Velocity ◽  
Stroke Frequency ◽  
Thoracic Temperature ◽  
Force Velocity ◽  
Contraction Kinetics ◽  
Wing Stroke ◽  
Tetanic Tension

1. Isometric contraction kinetics and force-velocity relations were examined in wing muscles of two tettigoniid insects, Neoconocephalus robustus and N. triops. The muscles were first tergocoxal muscles of the mesothoracic and metathoracic segments. The metathoracic muscle is a flight muscle. The mesothoracic muscle is used in flight and in stridulation. 2. In the field, the wing stroke frequency during stridulation by N. triops is about 100 Hz; the thoracic temperature during singing is about 30 C; and the temperature gradient between the thorax and surround is about 15 C. Published data for N. robustus give the wing-stroke frequency during stridulation as about 200 Hz at a thoracic temperature of 35–40 C. The wing-stroke frequency during flight by both species is approximately 20 Hz at 25 C. 3. The twitch time course is similar in equivalent muscles of the two species. At 35 C the twitch duration (onset to 50% relaxation) is 5.5-6.5 ms for mesothoracic muscles and 11–13 ms for metathoracic ones. Twitch and tetanic tension per unit area are about twice as great in the metathoracic muscles as in the faster, mesothoracic ones. 4. Despite the differences in isometric contraction kinetics, the maximum shortening velocity (Vmax) is similar in mesothoracic and metathoracic wing muscles. Vmax values (lengths per second, 35 C), determined by extrapolation of force-velocity curves, were 10.1 (mesothoracic) and 11.1 (metathoracic) for N. robustus; 12.2 (mesothoracic) and 16.1 (metathoracic) for N. triops. With N. triops, Vmax was also determined from the time taken to re-develop tension following quick release. The values obtained were somewhat higher than from extrapolation of force-velocity curves, but again similar for mesothoracic and metathoracic muscles. 5. Twitch time course becomes more rapid and Vmax increases with increasing temperature. Neither twitch nor tetanic tension is greatly affected by temperature change in the range 25–35 C. 6. As for many other fast muscles, force-velocity plots for these muscles have little curvature. It is suggested that the relative straightness of these plots is a consequence of internal viscosity.

Scientific contributions of A. V. Hill: exercise physiology pioneer

2002 ◽  
Vol 93 (5) ◽  
pp. 1567-1582 ◽  
Author(s):  
David R. Bassett
Keyword(s):  
World War Ii ◽  
Heat Production ◽  
Time Course ◽  
Exercise Physiology ◽  
Frog Muscle ◽  
World War ◽  
Academic Assistance ◽  
Physiological Adaptations ◽  
Velocity Equation ◽  
Force Velocity

Beginning in 1910, A. V. Hill performed careful experiments on the time course of heat production in isolated frog muscle. His research paralleled that of the German biochemist Otto Meyerhof, who measured the changes in muscle glycogen and lactate during contractions and recovery. For their work in discovering the distinction between aerobic and anaerobic metabolism, Hill and Meyerhof were jointly awarded the 1922 Nobel Prize for Physiology or Medicine. Because of Hill's interest in athletics, he sought to apply the concepts discovered in isolated frog muscle to the exercising human. Hill and his colleagues made measurements of O2 consumption on themselves and other subjects running around an 85-m grass track. In the process of this work, they defined the terms “maximum O2 intake,” “O2requirement,” and “steady state of exercise.” Other contributions of Hill include his discoveries of heat production in nerve, the series elastic component, and the force-velocity equation in muscle. Around the time of World War II, Hill was a leading figure in the Academic Assistance Council, which helped Jewish scientists fleeing Nazi Germany to relocate in the West. He served as a member of the British Parliament from 1940 to 1945 and as a scientific advisor to India. Hill's vision and enthusiasm attracted many scientists to the field of exercise physiology, and he pointed the way toward many of the physiological adaptations that occur with physical training.

Force-Velocity Relation in Throwing

1973 ◽  
Vol 44 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Shintaro Toyoshima ◽  
Mitsumasa Miyashita
Keyword(s):  
Velocity Relation ◽  
Force Velocity
Sign in / Sign up

Export Citation Format

Share Document