Erector spinae
Encyclopedia
The Erector spinæ is a muscle group of the back in humans and animals. It is also known as sacrospinalis in older texts. A more modern term is extensor spinae, though this is not in widespread use. The name of the muscle is pronounced e-rec-tor speen-aye, or e-rec-tor spinae-ee.
It is really not just one muscle, but a bundle of muscle
s and tendon
s. It is paired and runs more or less vertically. It extends throughout the lumbar, thoracic and cervical regions, and lies in the groove to the side of the vertebral column
.
Erector spinae is covered in the lumbar and thoracic regions by the Thoracolumbar fascia
, and in the cervical region by the nuchal ligament
.
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 which, on being followed upward, is subdivided into three columns; these gradually diminish in size as they ascend to be inserted into the vertebræ and ribs.
The erector spinae arises from the anterior surface of a broad and thick tendon, which is attached to the medial crest of the sacrum
, to the spinous processes of the lumbar and the eleventh and twelfth thoracic vertebræ, and the supraspinous ligament
, to the back part of the inner lip of the iliac crests and to the lateral crests of the sacrum, where it blends with the sacrotuberous and posterior sacroiliac ligament
s.
Some of its fibers are continuous with the fibers of origin of the Gluteus maximus.
The muscular fibers form a large fleshy mass which splits, in the upper lumbar region into three columns, viz., a lateral, the Iliocostalis, an intermediate, the Longissimus, and a medial, the Spinalis.
Each of these consists of three parts, inferior to superior, as follows:
Iliocostalis
:
The iliocostalis originates from the sacrum
, erector spinae aponeurosis and iliac crest
. The iliocostalis has three different insertions according to the parts:
Longissimus
:
The longissimus muscle has three parts with different origin and insertion:
Spinalis
:
The spinalis muscle, as usual, has three parts:
| Insertion >
Lateral Column
Iliocostalis
Intermediate Column
Longissimus
>-
| Lower thoracic vertebrae and ribs I. lumborum
| Upper thoracic vertebrae and ribs I. thoracis
L. thoracis
| Cervical vertebrae I. cervicis
L. cervicis
| Skull
L. capitis
From lateral to medial, the erector spinae muscles can be remembered using the mnemonic
, "I Long for Spinach" for Illiocostalis, Longissimus and Spinalis.
It is really not just one muscle, but a bundle of muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...
s and tendon
Tendon
A tendon is a tough band of fibrous connective tissue that usually connects muscle to bone and is capable of withstanding tension. Tendons are similar to ligaments and fasciae as they are all made of collagen except that ligaments join one bone to another bone, and fasciae connect muscles to other...
s. It is paired and runs more or less vertically. It extends throughout the lumbar, thoracic and cervical regions, and lies in the groove to the side of the vertebral column
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
.
Erector spinae is covered in the lumbar and thoracic regions by the Thoracolumbar fascia
Thoracolumbar fascia
The thoracolumbar fascia is a deep investing membrane which covers the deep muscles of the back of the trunk. It is made up of three layers, anterior, middle, and posterior. The anterior layer is the thinnest and the posterior layer is the thickest. Two spaces are formed between these three...
, and in the cervical region by the nuchal ligament
Nuchal ligament
The paxwax or nuchal ligament is a fibrous membrane, which, in the neck, represents the supraspinal ligaments of the lower vertebræ...
.
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 which, on being followed upward, is subdivided into three columns; these gradually diminish in size as they ascend to be inserted into the vertebræ and ribs.
The erector spinae arises from the anterior surface of a broad and thick tendon, which is attached to the medial crest of the sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
, to the spinous processes of the lumbar and the eleventh and twelfth thoracic vertebræ, and the supraspinous ligament
Supraspinous ligament
The supraspinal ligament is a strong fibrous cord, which connects together the apices of the spinous processes from the seventh cervical vertebra to the sacrum; at the points of attachment to the tips of the spinous processes fibrocartilage is developed in the ligament.It is thicker and broader in...
, to the back part of the inner lip of the iliac crests and to the lateral crests of the sacrum, where it blends with the sacrotuberous and posterior sacroiliac ligament
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 bones.It consists of numerous fasciculi, which pass between the bones in various directions....
s.
Some of its fibers are continuous with the fibers of origin of the Gluteus maximus.
The muscular fibers form a large fleshy mass which splits, in the upper lumbar region into three columns, viz., a lateral, the Iliocostalis, an intermediate, the Longissimus, and a medial, the Spinalis.
Each of these consists of three parts, inferior to superior, as follows:
Iliocostalis
Iliocostalis
The iliocostalis is the muscle immediately lateral to the longissimus that is the nearest to the furrow that separates the epaxial muscles from the hypaxial...
:
The iliocostalis originates from the sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
, erector spinae aponeurosis and iliac crest
Iliac crest
-External links: - "Superficial muscles of the gluteal region and posterior thigh." - "Anterior Abdominal Wall: Osteology and Surface Anatomy " - "The Back, Posterior View" * *...
. 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
Longissimus
The longissimus is the muscle lateral to the semispinalis. It is the longest subdivision of the sacrospinalis that extends forward into the transverse processes of the posterior cervical vertebrae.-Longissimus thoracis:...
:
The longissimus muscle has three parts with different origin and insertion:
- longissimus thoracis originates from the sacrum,the spinous process of lumbar vertebrate and transverse process of the last thoracic vertebrate and inserts in the transverse process of the lumbar vertebrate,erector spinae aponeurosis,ribs and coastal process of thoracic vertebrate.
- longissimus cervicis originates from the transverse proces of T6-T1 and inserts in the transverse process of C7-C2.
- longissimus capitis originates from the transverse process of T3-T1 runs through C7-C3 and inserts in the mastoid process of temporal bone.
Spinalis
Spinalis
The spinalis is the portion of the erector spinae, a bundle of muscles and tendons, located nearest to the spine. It is divided into three parts.-Spinalis dorsi:...
:
The spinalis muscle, as usual, 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 muscles fibres that runs from the cervical and upper thoracic which then inserts in the external occipital protuberance.
Iliocostalis
Iliocostalis
The iliocostalis is the muscle immediately lateral to the longissimus that is the nearest to the furrow that separates the epaxial muscles from the hypaxial...
Longissimus
Longissimus
The longissimus is the muscle lateral to the semispinalis. It is the longest subdivision of the sacrospinalis that extends forward into the transverse processes of the posterior cervical vertebrae.-Longissimus thoracis:...
Spinalis
The spinalis is the portion of the erector spinae, a bundle of muscles and tendons, located nearest to the spine. It is divided into three parts.-Spinalis dorsi:...
>-
| Lower thoracic vertebrae and ribs
| Upper thoracic vertebrae and ribs
| Cervical vertebrae
| Skull
From lateral to medial, the erector spinae muscles can be remembered using the mnemonic
Mnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
, "I Long for Spinach" for Illiocostalis, Longissimus and Spinalis.
Training
Examples of exercises by which the erector spinae can be strengthened for therapeutic or athletic purposes include, but are not limited to:- Bent-over rowBent-over rowA bent-over row is a weight training exercise that targets a variety of back muscles. Which ones are targeted varies on form. The bent over row is often used for both bodybuilding and powerlifting...
(unsupported) - DeadliftDeadliftThe deadlift is a weight training exercise where a loaded barbell is lifted off the ground from a stabilized, bent over position. It is one of the three canonical powerlifting exercises, along with the squat and bench press.-Overview:...
- HyperextensionHyperextension (exercise)A hyperextension is an exercise that works the lower back as well as the mid and upper back, specifically the erector spinae....
- Good-morningGood-morningThe good-morning is a weight-lifting exercise. The movement resembles bowing to greet someone "good morning". The erector spinae muscles of the lower back work isometrically to keep the spine in an extended position while the hamstrings and gluteus maximus work isotonically to perform hip extension...
- Pull-up (exercise)Pull-up (exercise)A pull-up is an upper body compound pulling exercise where the body is suspended by the arms, gripping something, and pulled up with muscular effort...
(back arched) - RowingWatercraft rowingWatercraft rowing is the act of propelling a boat using the motion of oars in the water. The difference between paddling and rowing is that with rowing the oars have a mechanical connection with the boat whereas with paddling the paddles are hand-held with no mechanical connection.This article...
- SquatSquat (exercise)In strength training, the squat is a compound, full body exercise that trains primarily the muscles of the thighs, hips and buttocks, quads , hamstrings, as well as strengthening the bones, ligaments and insertion of the tendons throughout the lower body...
- UttanasanaUttanasanaUttanasana|thumb|113pxUttanasana, variation|thumb|113pxUttanasana , Intense Forward-Bending Pose, Intense Strech Pose, Standing Forward Bend, Standing Forward Fold Pose, or Standing Head to Knees Pose, is an asana.-Etymology:...
