With no blood supply of it own, the disc is dependent on sponge action for attracting and absorbing nutrients from adjacent tissues. Muscles Your vertebra are supported and moved by many different muscles. If muscles are tight or weak, they create or worsen back pain. Joints are controlled by at least two sets of muscles, flexors which bend the joint, and extensors which straighten it. In addition, most joints have rotator muscles that twist and rotate your bones.
Good posture is only possible if the flexors, extensors, and rotators are in proper balance.
Your erector spine muscles are involved in movement and run the length of your spine. These muscles help you to bend over by resisting the force of gravity, and to straighten up by contracting and exerting great compressive force on your spine. Your abdominal muscles play an important role in helping to support the spine by maintaining pressure inside the abdomen. This pressure is an essential measure of counter support to the spine. These muscles help to flex your hips when walking or climbing stairs.