Fig. 7. Ensemble averages of electromyographic (EMG) activity of the abdominal portion of the external oblique muscle. This muscle has a locomotor function, revealed by a consistent bursting pattern in all dogs and a clear bursting pattern in the average across dogs. A ventilatory function is not evident, given the absence of bursting in the uncoupled breath averages. Samples are from four dogs (A-D), and the average across four dogs (E), with ventilatory (bold lines) and acceleration (thin lines) traces to reveal relationships to breath and stride (F). IF indicates ipsilateral forelimb support and CF contralateral forelimb support in the footfall bars at the bottom. All traces are on the same time scale. Exp., expiration; Insp., inspiration.