Skeletal muscles are the only voluntary muscles in the body. In order for muscles to contract, they must get instructions from the nerves. If a nerve suffers damage, communication between nerve and muscle is impaired and the muscle atrophies. Muscles of the body are given names based on location, function, size and structure. There are many muscles in the lower back; their strength is the key to minimizing lower back pain.
Quadratus Lumborum
The quadratus lumborum originates in the bone of the hip known as the illium and inserts at the fourth lumbar vertebrae and 12th rib. The quadratus lumborum is responsible for stabilizing the pelvis and lower spine. It's also responsible for flexing the torso and rotating the trunk. Lateral rotations and side planks are excellent exercises to strengthen the quadratus lumborum muscle.
Illiocostalis Lumborum
The illiocostalis lumborum, which originates in the sacral bone of the hip and lower bones of the vertebrae, inserts in the ribs. The illiocostatlis lumborum is responsible for rotating the trunk and flexing the torso. Trunk rotations and oblique flexion exercises strengthen the illiocostalis lumborum.
Longissimus
There are three longissimus muscles. They are the longissimus thoracis, longissimus cervicis and longissimus capitis. All three muscles originate and insert at various processes, or appendages, of the vertebral column. The longissimus muscles are responsible for flexing the head and neck simultaneously and rotating the spine to the same side. They also provide assistance in maintaining an erect spine. These muscles are strengthened by sitting erect and performing neck flexion and back extension exercises.
Spinalis
There are three spinalis muscles: the spinalis thoracis, spinalis cervicis and spinalis capitis. The spinalis muscles originate in various areas of the thoracic and lumbar spine and insert in various areas of the cervical spine. The spinalis muscles assist in maintaining an erect spine, bending backward, bending sideways and rotating the spine to the same side. Back extensions are exercises to strengthen the spinalis muscles.
Illiocostalis
There are three illiocostalis muscles: the illiocostalis lumborum, illiocostalis thoracis and illiocostalis cervicis. They all originate at various upper portions of the ribs and thoracic vertebrae, and insert in lower portions of the ribs and cervical vertebrae. The illiocostalis muscles provide assistance in maintaining an erect spine, rotating the spine to the same side, back extension and bending forward. Sitting erect and performing back extension exercises are ways to strengthen the illiocostalis muscles.
