(a) Forelimb muscle activity (Br; Musculus brachiocephalicus; Inf, M. infraspinatus; TB, long head of M. triceps brachii). (b) Hindlimb muscle activity (GM; M. gluteus medius, ST; M. semitendinosus, FDL; M. flexor digitorum longus). In all muscles, iEMG significantly increased with speed. The iEMG in Br and Inf was significantly higher in the leading than in the trailing. Conversely, the iEMG in GM and ST was significantly higher in the trailing than in the leading. Speed showed no interaction with the lead side. Data are shown as mean ± standard deviation. * indicates significant changes (P < 0.05) by generalized mixed model analysis followed by Tukey’s post hoc test.