A subtractive method for decomposing muscle tension into individual twitches.
When an isolated strip of skeletal muscle tissue is held at fixed length and stimulated electrically with a very brief pulse of electricity it responds with a transient increase in tension known as a twitch. If the same strip is stimulated repetitively with short pulses it produces a tension that can be considered to be composed of individual twitches arising from each stimulus. We present a subtractive method for decomposing a muscle tension curve into individual twitches of various heights. The locations of the twitches are known a priori from the times at which each stimulus was applied to the muscle. The shape of each twitch is assumed the same as that of a single twitch obtained just prior to the repetitive stimulation tension signal. We therefore find the heights of the individual twitches composing a tension curve. We find that most of a tension signal from isolated dog diaphragm strips can be accounted for as the sum of twitches of the same shape but different heights. We also derive a refractory factor, for stimulation at a given frequency, that describes how the heights of the twitches in a tension curve are attenuated as a function of stimulation frequency.
Bates
J H
JH
Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
Janssens
S
S
Jiang
T X
TX
Hunter
I W
IW
Decramer
M
M
D000818:Animals; D003964:Diaphragm / Q000502:physiology; D004285:Dogs; D008954:Models, Biological; D009119:Muscle Contraction