Suprascapular nerve
Encyclopedia
The suprascapular nerve arises from the upper trunk
(formed by the union of the fifth and sixth cervical nerves
). It innervates the supraspinatus muscle
s and infraspinatus muscle
s.
It runs lateralward beneath the Trapezius and the Omohyoideus, and enters the supraspinatous fossa
through the suprascapular notch
, below the superior transverse scapular ligament
; it then passes beneath the Supraspinatus, and curves around the lateral border of the spine of the scapula
to the infraspinatous fossa
.
In the supraspinatous fossa
it gives off two branches to the Supraspinatus muscle
, and an articular filament to the shoulder-joint; and in the infraspinatous fossa
it gives off two branches to the Infraspinatous muscle, besides some filaments to the shoulder-joint and scapula
.
Hard to start shoulder abduction
Upper trunk
The upper trunk is a trunk of the brachial plexus which derives from the C5 and C6 roots.Damage to the upper trunk causes:Arm hangs by side,Elbow can’t flex,Arm medially rotated,Forearm pronated,‘waiter’s tip’,...
(formed by the union of the fifth and sixth cervical nerves
Cervical nerves
The cervical nerves are the spinal nerves from the cervical vertebrae.Although there are seven cervical vertebrae , there are eight cervical nerves . All nerves except C8 emerge above their corresponding vertebrae, while the C8 nerve emerges below the C7 vertebra...
). It innervates the supraspinatus muscle
Supraspinatus muscle
The supraspinatus is a relatively small muscle of the upper arm that runs from the supraspinatous fossa superior of the scapula to the greater tubercle of the humerus. It is one of the four rotator cuff muscles and also abducts the arm at the shoulder...
s and infraspinatus muscle
Infraspinatus muscle
In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa. As one of the four muscles of the rotator cuff, the main function of the infraspinatus is to externally rotate the arm and stabilize the shoulder joint.-Origin and...
s.
It runs lateralward beneath the Trapezius and the Omohyoideus, and enters the supraspinatous fossa
Supraspinatous fossa
The supraspinatous fossa of the posterior aspect of the scapula is smaller than the infraspinatous fossa, concave, smooth, and broader at its vertebral than at its humeral end. Its medial two-thirds give origin to the Supraspinatus....
through the suprascapular notch
Suprascapular notch
The suprascapular notch is a notch in the superior border of the scapula, just medial to the base of the coracoid process...
, below the superior transverse scapular ligament
Superior transverse scapular ligament
The superior transverse ligament converts the scapular notch into a foramen or opening.It is a thin and flat fasciculus, narrower at the middle than at the extremities, attached by one end to the base of the coracoid process, and by the other to the medial end of the scapular notch.The...
; it then passes beneath the Supraspinatus, and curves around the lateral border of the spine of the scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
to the infraspinatous fossa
Infraspinatous fossa
The infraspinatous fossa of the scapula is much larger than the supraspinatous fossa; toward its vertebral margin a shallow concavity is seen at its upper part; its center presents a prominent convexity, while near the axillary border is a deep groove which runs from the upper toward the lower...
.
In the supraspinatous fossa
Supraspinatous fossa
The supraspinatous fossa of the posterior aspect of the scapula is smaller than the infraspinatous fossa, concave, smooth, and broader at its vertebral than at its humeral end. Its medial two-thirds give origin to the Supraspinatus....
it gives off two branches to the Supraspinatus muscle
Supraspinatus muscle
The supraspinatus is a relatively small muscle of the upper arm that runs from the supraspinatous fossa superior of the scapula to the greater tubercle of the humerus. It is one of the four rotator cuff muscles and also abducts the arm at the shoulder...
, and an articular filament to the shoulder-joint; and in the infraspinatous fossa
Infraspinatous fossa
The infraspinatous fossa of the scapula is much larger than the supraspinatous fossa; toward its vertebral margin a shallow concavity is seen at its upper part; its center presents a prominent convexity, while near the axillary border is a deep groove which runs from the upper toward the lower...
it gives off two branches to the Infraspinatous muscle, besides some filaments to the shoulder-joint and scapula
Scapula
In anatomy, the scapula , omo, or shoulder blade, is the bone that connects the humerus with the clavicle ....
.
Disorders
- Suprascapular paralysis is a common condition in veterinary medicine.
Hard to start shoulder abduction
External links
- Diagram at physsportsmed.com - "The major subdivisions and terminal nerves of the brachial plexus."
