Fig. 1. Illustration of the muscular sling of the pectoral girdle of therian mammals. (A) Schematic representation of the three primary components of the muscular sling. Muscles are represented by solid and broken lines, and labeled in black type; bones are labeled in grey type. Modified from (Davis, 1949). (B) Lateral view of the m. serratus ventralis muscle showing position of the electrodes in, the m. serratus ventralis cervicalis (i), m. serratus ventralis thoracis (ii) and the m. rhomboideus thoracis (iii). (C) Ventral view of the m. pectoralis muscle showing the position of the electrodes in, the m. pectoralis superficialis transverses (iv) and m. pectoralis profundus (v).