Levator scapula -history function structure and origin

The Levator scapulae are the Axio-appenducular posterior muscle that connects the upper
limb to the vertebral column and lies in the posterior triangle of the neck. The upper part of
the levator scapulae is covered by the sternocleidomastoid, and its lower part is the
trapezius.


The Levator scapulae is a long, slender natural tissue located beneath the upper layer of the
posterior body tissues. Functionally, however, it is considered to be the muscle of the main
movement and the rhomboids, the serratus anterior, the serratus posterior upper and lower
muscle. The muscles of the levator scapulae extend from the flexible systems of the
vertebrae C1-C4 to the medial border of the scapula.


As its name suggests, the main function of these muscles is to enlarge the scapula. In
addition, the levator scapulae works with the trapezius, latissimus dorsi, rhomboids, large
pectoralis and pectoralis muscles to slightly rotate the glenoid cavity, tighten the spine, and
stretch and later flex the neck.

History


levator is from medical Latin word levator “means a lifter,” from Latin word levatus, past
the participle of the lever “to raise”.


Levator scapulae :


Origin:

laying across the process of the first four cervical vertebrae (posterior tubercles of C3
and C4 laying across processes)


Structure of Levator scapula


The scapulae of the levator arise from the posterior cervical vertebrae. Muscles are inserted
into the medial border of the scapula from the upper part to the junction of the spine and
the medial border of the scapula.
The levator scapulae can lie deep in the Sternocleidomastoid where it originates, deep or
close to splenius capitis in its beginning and middle, and deep in the trapezius in its lower
part.


Relations


The Levator scapulae occupy the upper layer of the posterior (outer) tissues. The upper part
of the muscle lies below the splenius capitis and the sternocleidomastoideus muscle, and
the lower part is covered by the trapezius. As a result, muscles can easily be trapped in this
area. In addition, the middle part helps to form the bottom triangle of the neck.


Blood supply


the dorsal scapular artery is supplied from The levator scapulae. Normally, this artery has a
small branch that extends beyond the supraspinatus fossa of the scapula, and in all three
cases, this branch supplies muscles. When the dorsal scapular artery exits the cervical
vertebrae, the arterial cervical artery divides, the dorsal scapular artery passes through the
center, while the transient cervical artery passes later.


A large portion of the levator scapulae tissue is regenerated by two branches of the
thyrocervical stem; ascending and ascending cervical vertebrae. In addition, the vertebral
portion of the muscle is supplied by the vertebral artery.


The function of Levator scapula :


When the spine is straightened, the levator scapulae raises the scapula and rotates its lower
angle slightly. It usually works in conjunction with other muscles such as the rhomboids and
the pectoralis small around the floor.


Lifting or alternating one shoulder at a time may require muscles to stabilize the cervical
spine and keep it in place so that it does not rotate. Raising both simultaneously with equal
pulling values on both sides of the origin of the cervical spine may contradict these
ceremonies. Lower rotation can be prevented by joining the other muscles that raise the
spine, the upper straps of the trapezius, which is the rotator cuff.


When the shoulder is adjusted, the levator scapulae rotate in the same direction and rotate
the cervical spine later. When both shoulders were straightened, simultaneous contraction
of the levator scapulae muscles in equal amounts would not produce lateral rotation or
rotation and may result in direct rotation or extension of the cervical spine.


Position of Levator scapula


The upper third of the strap-like levator scapulae lies deep in the sternocleidomastoid while
the lower third is deep in the trapezius. From the evolving processes of the upper cervical
spine, the levator fibers of the scapula pass slowly to the highest border of the scapula.


Embryology


The muscles of the Levator scapulae are found in the paraxial mesoderm and the large and
small rhomboid. Their development is caused by tailbud neuroectodermal progenitors by
fibroblast growth factor (FGF) and Wnt signaling. The dorsal scapular nerve is located in the
internal (motor) ram’s C5. Internal roots originate from the basal region of the spinal plate.
Anatomic variation of the subclavian artery may be affected by failed brachial plexus blocks.
Nurses performed supraclavicular brachial plexus blocks for analgesia and anesthesia of the
upper leg.


Nerves supply


The insertion into the levator scapulae itself is from the dorsal scapular vein, or DSN, from
the C4 and C5 roots. This nerve also provides motor retention in the rhomboid. The DSN
arises from the inner rami of the C5 root, from the upper brachial plexus, and is traditionally
the first branch of the nerve from the C5 root. Survival can also occur in the cervical arteries
(C3, C4) through the cervical plexus.


The levator scapulae is provided by two or three branches of the third and fourth cervical
nerves, and is often a branch from the dorsal scapular nerve.


Note :


Levator Scapulae Syndrome
The most common clinical manifestation of levator scapulae pathology is levator scapulae
syndrome or tenderness over the upper medial angle of the scapula. Though well
documented, this condition is often unrecognized. There is a hypothesis that constant
trigger points, crepitation, and increased heat emission result from a combination of
anatomic variability and the confluence of a bursa between the insertion of the levator
scapulae, origin serratus anterior and the scapula. Effective treatment modalities include
physical therapy and/or local corticosteroid injections


Snapping Scapula Syndrome
shoulder dysfunction is present as painful scapulothoracic bursitis, termed snapping
scapula syndrome or “washboard syndrome.” This condition commonly manifests secondary
to a chronic injury, overuse, or muscle imbalance that impacts the scapulothoracic
articulation. Osseous lesions at the superomedial angle of the scapula secondary to
repetitive injury or avulsion of the levator scapulae have also been implicated in the clinical
manifestation. This condition may be more common in military personnel due to chronic
stress and recurrent injury secondary to load-bearing activities of the upper extremity. The
rate of successful treatment is 80%. For those that fail conservative treatment, arthroscopic
bursectomy with or without partial scapulectomy is the most effective treatment modality.

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