The skeletal system includes the bones of the skeleton and the cartilages, ligaments, and other connective tissue that stabilize or connect the bones. In addition to supporting the weight of the body, bones work together with muscles to maintain body position and to produce controlled, precise movements. Without the skeleton to pull against, contracting muscle fibers could not make us sit, stand, walk, or run. The skeletal system includes the bones of the skeleton and the cartilages, ligaments, and other connective tissue that stabilize or connect the bones. In addition to supporting the weight of the body, bones work together with muscles to maintain the body’s position and to produce controlled, precise movements. Without the skeleton to pull against, contracting (tightened) muscle fibers could not make us sit, stand, walk, or run. Each bone in the skeleton contains two forms of tissue: compact (dense) bone that is relatively solid, and spongy (cancellous) bone that forms an open network of struts and plates. Compact bone is found on the external surface of the bone; spongy bone is located inside the bone. The amount of compact and spongy bone depends on the shape of the bone. Compact bone is thickest where stresses arrive from a limited range of directions. Spongy bone is located where bones are not heavily stressed or where stresses arrive from many directions. Spongy bone is much lighter than compact bone, which helps reduce the weight of the skeleton and makes it easier for muscles to move the bones. You can share your ideas & comments further at : editor.cro@peerjournal.org clinortho@eclinicalsci.com