The supraspinous fossa (supraspinatus fossa, supraspinatous fossa) of the posterior aspect of the

scapula The scapula (: scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side ...

(the shoulder blade) is smaller than the infraspinous fossa, concave, smooth, and broader at its

vertebral Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bone and some hyaline cartilage, that make up the vertebral column or spine, of vertebrates. The proportions of the vertebrae differ according to their spina ...

than at its humeral end. Its medial two-thirds give origin to the

Supraspinatus The supraspinatus (: supraspinati) is a relatively small muscle of the upper back that runs from the supraspinous fossa superior portion of the scapula (shoulder blade) to the greater tubercle of the humerus. It is one of the four rotator cuff m ...

Structure

The fossa can be exposed by the removal of skin and the

superficial fascia A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. Th ...

of the back and the

trapezius muscle The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the human spine, spine and laterally to the spine of the scapula. It moves the scapula and ...

. The supraspinous fossa is bounded by the

spine of scapula The spine of the scapula or scapular spine is a prominent plate of bone, which crosses obliquely the medial four-fifths of the scapula at its upper part, and separates the supra- from the infraspinatous fossa. Structure It begins at the vertica ...

on the inferior side, acromion process on the lateral side and the superior angle of scapula on the superior side. Supraspinatus muscle originates from the supraspinous fossa. Distal attachment of the

levator scapulae muscle The levator scapulae is a slender skeletal muscle Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous s ...

is also on the medial aspect of the fossa.

Function

The

suprascapular artery The suprascapular artery is a branch of the thyrocervical trunk on the neck. Structure At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses t ...

and

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

are found within the fossa. The posterior branch of the suprascapular artery supplies the supraspinatous muscle. Dorsal scapular artery also gives off a collateral branch and

anastomoses An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf#Veins, leaf veins, or streams. Such a connection may be ...

with the suprascapular artery. Suprascapular nerve from the

brachial plexus The brachial plexus is a network of nerves (nerve plexus) formed by the anterior rami of the lower four Spinal nerve#Cervical nerves, cervical nerves and first Spinal nerve#Thoracic nerves, thoracic nerve (cervical spinal nerve 5, C5, Cervical spi ...

passes through the suprascapular notch as it approaches the fossa to supply the supraspinatus muscle. Suprascapular artery and nerve descend together but are separated by the superior transverse scapular ligament at the suprascapular notch.

Clinical significance

Rotator cuff tear

Hollowing in the supraspinous and the infraspinous area is frequently seen as chronic rotator cuff tear resulting in wasting. The wasting may be caused by the supraglenoid cyst compressing the suprascapular nerve and causes a loss of innervation to supraspinatus and infraspinatus muscles. Such wasting or hollowing can be differentially diagnosed as nerve compression or tendon rupture.

Additional images

File:Posterior surface of scapula.jpg, The human scapula File:Supraspinous fossa of left scapula - animation01.gif, Supraspinous fossa shown in red. File:Supraspinous fossa of scapula - animation02.gif, Supraspinous fossa shown in red.

References

External links

* {{Authority control Scapula