Fig. 9. Ensemble averages of electromyographic (EMG) activity of the transversus abdominis muscle. This muscle shows clear bursting in all ensemble averages, consistently across dogs, indicating both a ventilatory and locomotor function. The pattern of activity relative to the ventilatory cycle reveals an expiratory function for this muscle. 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.