Fig. 9. Means of binned rectified EMG traces of the external oblique muscle during (A) coupled walking: breathing and footfall in phase, (B) uncoupled running relative to breath: the onset of expiratory airflow to the end of inspiratory airflow and (C) uncoupled running relative to stride: one stride length. Data are presented from Goose A, averaged over 20 breaths or 20 strides. The external oblique is an expiratory muscle and demonstrates no locomotor activity.