Mechanical power output of locust flight muscle

Abstract

1. The mechanical work and power output of locust flight muscle were measured during cyclic contraction at normal flight frequency and operating temperature by subjecting muscle to sinusoidal length change and phasic stimulation at selected points in the length cycle. 2. With a single stimulus per cycle, work output averaged 2.1 J/kg muscle inSchistocerca nitens and 2.4 J/kg muscle inS. americana gregaria (power output 52 and 49 W/kg respectively) (Table 1). 3. Work was maximal at imposed length changes of about 4% of resting muscle length and at stimulus phases such that maximum tension occurred at the midpoint of the shortening phase of the length change (Table 1). 4. With multiple stimulation, power output can be increased about 20% above that obtained with a single stimulus per cycle (up to about 73 W/kg muscle) (Fig. 2).