Fig. 8. Summary diagram showing the onset and duration of lateral hypaxial muscle activity relative to maximum body bending and footfall pattern in three Ambystoma tigrinum during walking. Means and standard deviations for -bursts (filled bars), ß-bursts (open bars) and limb onset and offset times are calculated from values normalized to stride duration. -bursts occur during every locomotor cycle, whereas ß-bursts are facultative. The S.D. of the normalized time of maximum opposite bending is plotted on a point in the center of the body. LH, left hindlimb; LF, left forelimb; RH, right hindlimb; RF, right forelimb. Sample sizes (N): individual A, TA=28, TA_ß=25, OI=27, OI_ß=27, OEP=28, OEP_ß=23, OES=26, OES_ß=26; individual B, TA=30, TA_ß=28, OI=31, OI_ß=31, OEP=21, OEP_ß=27, OES=31, OES_ß=31; Individual C, TA=37, TA_ß=6, OI=38, OI_ß=28, OES=38, OES_ß=10. OES, m. obliquus externus superficialis; OEP, m. obliquus externus profundus; OI, m. obliquus internus; TA, m. transversus abdominis. *Denotes the side of the body on which the electrodes were implanted.