Fig. 9. Effect of strain on force depression due to active shortening in muscles 178 (filled, blue symbols) and 179 (open, red symbols). The solid blue line represents a regression of the data for muscle 178 (force depression=-0.01+4.90xstrain, R²=0.64; P<0.0001), whereas the broken red line represents a regression of the data for muscle 179 (force depression=-0.93+5.22xstrain, R²=0.56; P<0.0001). Each type of symbol represents a different initial length (circles, rest length; squares, RL+1 mm; diamonds, RL+2 mm; triangles, RL+3 mm). The muscles were shortened at 100 mm s^-1 and stimulated with the 3s pattern. N=5 animals for each muscle.