Lower Back Muscle
Though the back and spine are composed of hundreds of individual elements, the spine is a comprehensive unit that moves together as we consciously rotate, bend, flex, and extend our backs. There are muscles in front of, in back of, and that attach to the sides of our spine that enable us to move in every direction. As we extend, or arch our backs, the muscles that attack to the backs of our spines are contract, while the muscles in front of our spines relax. As we flex our body (bend forward), the abdominal muscles and those that connect to the front of our spines contract while our back muscles relax. When our bodies are in the neutral position, such as when we are sitting or standing in place, the pull of the muscles on both sides of our bodies must be of relatively equal value, or the spine may be pulled out of its normal position. Here we will discuss the role of the lower back muscle in protecting and balancing the spine, how its soft tissues may be affected by muscle injury or weakness, and some back exercises that may be done to restore the stability of the back.
The muscles which support and move the back are among the longest in our bodies, but they are relatively weak for the amount of work they are required to do. The back muscles may be under increased strain when we gain weight, loss muscle mass as part of the aging process, and when there are weaknesses or muscle imbalances. When muscle weaknesses and imbalances occur, our pine may be pulled out of its normal alignment, causing accelerated aging to the intervertebral discs, vertebral bodies, facet joints, and other soft tissues. Muscle problems may be the cause of your back pain. Muscle strengthening may also be the solution to your back problem.
The following are the lower back muscles that move the lower back and middle back. Remember the importance of muscle balance. For a person to have and sustain back health, a person must have good core strength in these muscles, as well as the abdominal muscles and those muscles that originate or insert into the front of the spine.
Click on the following links to find out more information about these lower back muscles.
- Latissimus Dorsi: The latissimus dorsi muscle is a wide muscle that originates in the lower six thoracic vertebrae and lumbar vertebrae, and sacrum. This muscle inserts into the top of the humerus, near the shoulder. The latissimus dorsi muscle adducts, medially rotates, and extends the arm at the shoulder.
- External Oblique: The external oblique muscle is one of the three major abdominal muscles. The other important abdominal muscles include the internal abdominal oblique, transverse abdominus, and rectus abdominus. The external oblique muscle is a lower back muscle that originates in the external surfaces of ribs 5-12. This lower back muscle inserts into the abdominal aopneurosis to linea alba and the anterior iliac crest. This muscle, when contracted, aides the body in the motor movements of flexion (forward bending) of the torso and lateral rotation of the spine.
- Gluteus Maximus: The gluteus maximus is included as a lower back muscle because of its location near the sciatic nerve, and due to the fact that lower back pain conditions also affect the muscles and structures of the hip and buttocks. The gluteus maximus muscle has points of origination at the medial and posterior borders of the ilium (hip bone), and sacrum/coccyx. The coccyx is our tail bone. This muscle covers the majority of our buttocks and inserts into the lateral side of our upper femur. This muscle allows for abduction of the thigh and lateral rotation of the hip. Compression of the L5, S1, or S2 spinal nerve roots may cause pain or weakness in this muscle.
- Serratus Posterior
- Internal Oblique
- Deep Hip Muscles
- Psoas Muscles