The mechanical power output of a striated muscle will be determined by measuring muscle tension as the muscle is subjected to periodic length change and to stimuli which occur at selected phases of the length cycle. The plot of muscle tension against length over a cycle forms a loop whose area is the work done by or on the muscle for that cycle. The goals of this project are: 1) To combine mechanical power measurements from insect wing muscles with simultaneous measurement of oxygen consumption in order to measure the efficiency of the muscle in converting metabolic to mechanical power, and to determine if the operating conditions which maximize power output are also those which maximize efficiency. 2) To extend power measurements to muscles other than insect wing muscles in order to determine how similar or dissimilar are muscles from different sources in their capacity for mechanical power output. 3) To characterize force- velocity curves for both shortening and lengthening muscles at different times after stimulation, and to use this information to create a model which will allow estimation of the power output from a muscle subjected to periodic length change and phasic stimulation. 4) To characterize release inactivation in muscle, and to determine the extent to which release inactivation affects power output during repetitive contraction.
