The erector spinae ( ) or spinal erectors is a set of

muscles Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

that straighten and rotate the

back The human back, also called the dorsum (: dorsa), is the large posterior area of the human body, rising from the top of the buttocks to the back of the neck. It is the surface of the body opposite from the chest and the abdomen. The vertebral c ...

. The spinal erectors work together with the glutes (

gluteus maximus The gluteus maximus is the main extensor muscle of the hip in humans. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in ...

, gluteus medius and gluteus minimus) to maintain stable posture standing or

sitting Sitting is a basic action and resting position in which the body weight is supported primarily by the bony ischial tuberosities with the buttocks in contact with the ground or a horizontal surface such as a chair seat, instead of by the low ...

Structure

The erector spinae is not just one muscle, but a group of

muscle Muscle is a soft tissue, one of the four basic types of animal tissue. There are three types of muscle tissue in vertebrates: skeletal muscle, cardiac muscle, and smooth muscle. Muscle tissue gives skeletal muscles the ability to muscle contra ...

s and

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

s which run more or less the length of the spine on the left and the right, from the

sacrum The sacrum (: sacra or sacrums), in human anatomy, is a triangular bone at the base of the spine that forms by the fusing of the sacral vertebrae (S1S5) between ages 18 and 30. The sacrum situates at the upper, back part of the pelvic cavity, ...

, or sacral region, and hips to the base of the

skull The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. They are also known as the sacrospinalis group of muscles. These muscles lie on either side of the spinous processes of the vertebrae and extend throughout the

lumbar In tetrapod anatomy, lumbar is an adjective that means of or pertaining to the abdominal segment of the torso, between the diaphragm (anatomy), diaphragm and the sacrum. Naming and location The lumbar region is sometimes referred to as the lowe ...

thoracic The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main ...

, and cervical regions. The erector spinae is covered in the lumbar and thoracic regions by the

thoracolumbar fascia The thoracolumbar fascia (lumbodorsal fascia or thoracodorsal fascia) is a complex, multilayer arrangement of fascial and aponeurotic layers forming a separation between the paraspinal muscles on one side, and the muscles of the posterior abdomina ...

, and in the cervical region by the

nuchal ligament The nuchal ligament is a ligament at the back of the neck that is continuous with the supraspinous ligament. Structure The nuchal ligament extends from the external occipital protuberance on the skull and median nuchal line to the spinous p ...

. This large muscular and tendinous mass varies in size and structure at different parts of the vertebral column. In the sacral region, it is narrow and pointed, and at its origin chiefly tendinous in structure. In the lumbar region, it is larger, and forms a thick fleshy mass. Further up, it is subdivided into three columns. They gradually diminish in size as they ascend to be inserted into the vertebrae and ribs. The erector spinae is attached to the medial crest of the sacrum (a slightly raised feature of the sacrum closer towards the midline of the body as opposed to the "lateral" crest which is further away from the midline of the body), to the spinous processes of the lumbar, and the eleventh and twelfth thoracic vertebrae and the

supraspinous ligament The supraspinous ligament (also known as the supraspinal ligament) is a ligament extending across the tips of the spinous processes of the vertebra of the vertebral column. Anatomy The supraspinous ligament connects the tips of the spinous proces ...

, to the back part of the inner lip of the iliac crests (the top border of the hips), and to the lateral crests of the sacrum, where it blends with the

sacrotuberous The sacrotuberous ligament (great or posterior sacrosciatic ligament) is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends. Structure It runs from the sacrum (the lower ...

and

posterior sacroiliac ligament The posterior sacroiliac ligament is situated in a deep depression between the sacrum and ilium behind; it is strong and forms the chief bond of union between the bone A bone is a rigid organ that constitutes part of the skeleton in mo ...

s. Some of its fibers are continuous with the fibers of origin of the

. The muscular fibers form a large fleshy mass that splits, in the upper lumbar region, into three columns, viz., a lateral (iliocostalis), an intermediate (longissimus), and a medial (spinalis). Each of these consists of three parts, inferior to superior, as follows:

Iliocostalis

The iliocostalis originates from the

, erector spinae aponeurosis, and

iliac crest The crest of the ilium (or iliac crest) is the superior border of the wing of ilium and the superolateral margin of the greater pelvis. Structure The iliac crest stretches posteriorly from the anterior superior iliac spine (ASIS) to the posterio ...

. The iliocostalis has three different insertions according to the parts: * iliocostalis lumborum has the lumbar part (where its insertion is in the 12th to 7th ribs). * iliocostalis thoracis where its insertion runs from the last 6 ribs to the first 6 ribs. * iliocostalis cervicis which runs from the first 6 ribs to the posterior tubercle of the transverse process of C6-C4.

Longissimus

The longissimus muscle is the intermediate and the largest of the three columns. It has three parts with different origin and insertion: * longissimus thoracis originates from the sacrum, spinous processes of the lumbar vertebrae, and transverse process of the last thoracic vertebra and inserts in the transverse processes of the lumbar vertebrae, erector spinae aponeurosis, ribs, and costal processes of the thoracic vertebrae. * longissimus cervicis originates from the transverse processes of T6-T1 and inserts in the transverse processes of C7-C2. *

longissimus capitis The longissimus () is the muscle lateral to the semispinalis muscles. It is the longest subdivision of the erector spinae muscles that extends forward into the transverse processes of the posterior cervical vertebrae. Structure Longissimus tho ...

originates from the transverse processes of T3-T1, runs through C7-C3, and inserts in the mastoid process of the temporal bone.

Spinalis

The spinalis muscle is the smallest and most medial column. It has three parts: * spinalis thoracis which originates from the spinous process of L3-T10 and inserts in the spinous process of T8-T2. * spinalis cervicis originates from the spinous process of T2-C6 and inserts in the spinous process of C4-C2. * spinalis capitis is an inconstant muscle fiber that runs from the cervical and upper thoracic and then inserts in the external occipital protuberance. From lateral to medial, the erector spinae muscles can be remembered using the

mnemonic A mnemonic device ( ), memory trick or memory device is any learning technique that aids information retention or retrieval in the human memory, often by associating the information with something that is easier to remember. It makes use of e ...

, I Love Spine. I lliocostalis, Love Longissimus and Spine Spinalis.

Training

Below are examples of exercises by which the erector spinae can be strengthened for therapeutic or athletic purposes. Additionally, exercises of the glutes may also be beneficial to lower back health. Care should be taken to avoid injury to the lower back when targeting spinal erectors directly. Exercises include, but are not limited to: * Bent-over row *

Deadlift The deadlift is a strength training exercise in which a weight-loaded barbell is lifted off the ground to the level of the hips, with the torso perpendicular to the floor, before being placed back on the ground. It is one of the three powerlifting ...

* Hyperextension * Good-morning *

Pull-up (exercise) A pull-up is an upper-body strength exercise. The pull-up is a Closed kinetic chain exercises, closed-chain movement where the body is suspended by the hands, gripping a bar or other implement at a distance typically wider than shoulder-width, ...

Rowing Rowing is the act of propelling a human-powered watercraft using the sweeping motions of oars to displace water and generate reactional propulsion. Rowing is functionally similar to paddling, but rowing requires oars to be mechanically a ...

* Squat * Utkatasana * Bridge (exercise) *

Plank (exercise) The plank (also called a front hold, hover, or abdominal bridge) is an isometric exercise, isometric core (anatomy), core strength exercise that involves maintaining a position similar to a push-up. Form The most common plank is the forearm p ...

Push-up The push-up (press-up in British English) is a common calisthenics Physical exercise, exercise beginning from the prone position. By raising and lowering the body using the arms, push-ups exercise the pectoralis major muscle, pectoral muscl ...

Additional images

Image:Gray236.png, Right hip bone. Internal surface. Image:Gray388.png, Diagram of a transverse section of the posterior abdominal wall, to show the disposition of the lumbodorsal fascia Image:Gray803.png, The posterior divisions of the sacral nerves Image:Gray1126.png, Transverse section, showing the relations of the capsule of the kidney Image:Gray1211.png, Surface anatomy of the back Image:LumbarTriangle.jpg, Lumbar triangle

References

External links

Video: Erector Spinae Muscle Group (back muscles)
* - "Intermediate layer of the extrinsic muscles of the back, deep muscles."
ithaca.edu
{{Authority control Muscles of the torso Spine extensors Medical mnemonics