Figure 4.

The appropriate scapular positions estimated for (a, b) Felis, (c, d) Rattus and (e, f) Chamaeleo in rotation models with the centre of mass (COM) accelerated vertically. (a, c, e) The scapular positions at which the net roll (SP_R) and yaw (SP_Y) moments generated by the contractive forces of the thoracic muscle fascicles (F _max) and the downward gravity forces (n × F_COM: n = 1, 2, 3, 4) applied to the fascicle origins and the centre of mass (COM), respectively, become zero; (b, d, f) The scapular positions at which the net pitch moment generated by the F _max and n × F_COM (SP _P−n: n = 1, 2, 3, 4) become zero. The results are shown in the oblique views in orthographic projection. COM, centre of mass of the uplifted body element (UB); P, a common pivot of the UB and TS about roll, yaw and pitch axes; TS, thoracic skeleton.