Scapula (shoulder blade) is the largest of the bones that make up each half of the pectoral (shoulder) girdle. It is a flat triangular bone, providing anchorage for the muscles of the forelimb and an articulation for the humerus at the glenoid cavity. It is joined to the clavicle (collar bone) in front. Clavicle is a bone that forms part of the pectoral (shoulder) girdle, linking the scapula (shoulder blade) to the stemum (breast bone). In humans it forms the collar bone and serves as a brace for the shoulders. Humerus is the long bone of the upper arm which articulates with the scapula (shoulder blade) at the glenoid cavity and with the ulna and radius (via a condyle) at the elbow. Ilium is the largest of the three bones that make up each half of the pelvic girdle. The ilium bears a flattened wing of bone that is attached by ligaments to the sacrum.