The intramuscular co-ordination within complex structured muscles is not sufficiently clarified, in particular during cyclic movement. This is however a condition for physiologically justified FES (functional electrical stimulation). The aim of the present study was to investigate further details in the intramuscular activation pattern of rat's triceps brachii. In earlier studies grid electrodes were used, which were chronically implanted on the muscle fascia (Biedermann et al., 2000). Additionally two array electrodes (2x8 channels) were applied intramuscularly into the c. longum and c. laterale of the triceps muscle. The EMG was recorded (10-700 Hz, sampling rate 4000 Hz, 0,488 mV/bit) simultaneously with high-speed videography during locomotion. The rectified and smoothed EMG was time normalised to the stance phase. The results show that the two electrode types, multichannel grid electrodes and intramuscular electrodes, could drive very similar samples. The results confirm the fundamental differences concerning the activation between stance and swing phase (Schumann et al., 2002). Likewise a preactivation of the c. longum during touch down maneuver can be recognised. Supported by Bundesministerium für Bildung und Forschung (No.: 01EZ0335)