of the wall of the chest, orthorax. The connection of the ribs to the breastbone—thesternum—is in all cases a secondary one, brought about by the relatively pliablerib(costal) cartilages. The small joints bet
Multiple muscles in the back function specifically in movements of the back. The erector spinae muscles, for example, extend the back (bend it backward) and side bend the back. The semispinalis dorsi and semispinalis capitis muscles also extend the back. The small muscles of the vertebrae (...