Fig. 6. Ensemble averages of electromyographic (EMG) activity of the thoracic portion of the external oblique muscle. This muscle clearly functions in both ventilation and locomotion, and the bursting pattern is consistent among dogs in both uncoupled stride and breath averages. Bursting starting at peak inspiratory airflow and extending to peak expiratory airflow 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.