Intrinsic muscles help you maintain your posture, bend, rotate your body, or flex your back. Intrinsic muscles are divided into three categories, making up many smaller, interconnected muscles.

Back muscles are grouped into three categories. Superficial (extrinsic) back muscles help you move your shoulders, intermediate back muscles help you breathe, and intrinsic (deep) back muscles ...

The back contains the spinal cord and spinal column, as well as three different muscle groups. Many conditions and injuries can affect the back. Learn more here.

Strengthen your back muscles and reduce back pain by adding these exercises to your fitness routine. Our backs are made up of 140 overlapping muscles — most of which we’re under-utilizing ...