Fig. 9. Bar charts of the average activity of the oblique (A) and intercostal (B) muscles from four dogs during running uphill (filled columns) and downhill (open columns). Values are means + S.E.M. The rectified and integrated area of 20 stride cycles was averaged for each dog, and an average value was then calculated from the mean value of the four dogs (N=4). Results are presented as a percentage of values obtained during running on the level. Paired t-tests were used to evaluate whether there was a significant difference between the slope and level trials. Muscles with P-values of greater than 0.05 were taken to be not significantly different and are marked NS.