Figure 13-16
The anuran caudopelvic mechanism for saltation. In stationary posture the ilio-sacral and sacro-urostylic joints are flexed, resulting in angulation between the ilia + urostyle and the sacrum + presacral vertebrae. During the early phase of a jump, this angle increases as the trunk extends. Extension of the trunk occurs through the action of the longissimus dorsi and coccygeo-sacralis muscles. This movement entails rotation at the ilio-sacral joints and the extension at the sacro-urostylic joint (after Jenkins and Shubin, 1998). |