... and shortening velocity were studied because they may be important variables affecting this so-called prestretch effect. Seven gastrocnemius medialis (GM) muscles of the rat were examined. Tetanic, isovelocity shortening contractions from 3 mm above muscle optimum length (l 0 ) to l 0 — 2 mm, at velocities of 10...

... length and shortening velocity were estimated 30 ms after release and compared with the PI length velocity curve determined at the same force level. For shortening above the optimum length, about half of the enhanced shortening found after prestretch could be explained by PS—PI fibre length differences...

... prephase. Duration of the active prephase (prestretch and pre-isometric) varied from 20 to 200 ms. Subsequent shortening (from optimum length+4 mm to optimum length-2 mm) lasted 150 ms. Stretch velocities of 5, 10 and 20mms −1 were used, and the shortening velocity was 40mms −1 . The effects of several...