Surface EMC-recordings using a miniaturised matrix electrode: a new technique for small animals

A new method for multichannel surface-EMG measurements in small animals is presented. The underlying scientific aim is the characterisation of the spr eading and the co-ordination of skeletal muscle activation between differen t muscles or muscle parts, depending on various motor tasks. The myoelectri cal signals were recorded monopolarly by a 16-channel matrix electrode on t he muscle surface directly under the skin on the fascia of the investigated muscle, without damaging the muscle. Surface-EMG's were recorded for at le ast 5 days after surgery without electrical interferences. During defined m otor tasks, the projection of the myoelectrical activation of the different parts of the M. triceps brachii of rats (Rattus norvegicus), pikas (Ochoto na rufescens) and cuis (Galea musteloides) or the M. anconeus of toads (Buf o marinus) on the muscle surface was mapped. The locomotion of the investig ated animals was monitored by a three-dimensional kinematic analysis (video and/or high-speed cineradiography). There was no perceptible influence fro m application of EMG matrix electrode. The miniaturised matrix electrode se emed practicable in gaining insight into changes in myoelectrical activatio n patterns (EMG mapping). This allows a characterisation of the intramuscul ar co-ordination processes corresponding to the actual morphofunctional sta te of the investigated animals. (C) 2000 Elsevier Science B.V. All rights r eserved.