Determination of small rapid volume changes in a muscle during activity

A METHOD has been developed for measuring small rapid volume changes occurring in a muscle during a single twitch. In order to achieve the necessary sensitivity and speed of response, a capacitance transducer has been developed which uses a commercially available detector-amplifier circuit (the ‘Dynagage’, from Photocon Products). The changes are displayed on a cathode-ray oscilloscope. Single gastrocnemius and sartorius muscles from Rana pipiens are used.