Analysis of the Mechanical Responses of Metathoracic Extensor Tibiae Muscles of Free-Walking Locusts

1. Two techniques for indirectly measuring the mechanical responses of metathoracic extensor tibiae muscles (METM9s) of free-walking locusts are described. 2. First, processed data from neurograms of free-walking (donor) locust preparations were used to stimulate the neurones innervating the METM9s of restrained (recipient) preparations. The mechanical responses of the METM9s of the recipient locusts were recorded isometrically. 3. Second, an electronic model of the METM was designed to give simulated electrical and mechanical responses following activation with processed neurographic data from donor locusts. 4. Both of these techniques give only an indirect estimate of the mechanical responses of the donor METM9s and do not take into account the complex relationships between tension and length in these muscles. 5. The mechanical responses of the METM during a variety of activities, especially walking, kicking and jumping, have been studied using these techniques and further information on the functional role of excitatory and inhibitory motorneurones has been obtained.