The rhomboid muscles (), often simply called the rhomboids, are
rhombus
In plane Euclidean geometry, a rhombus (plural rhombi or rhombuses) is a quadrilateral whose four sides all have the same length. Another name is equilateral quadrilateral, since equilateral means that all of its sides are equal in length. The ...
-shaped muscles associated with the
scapula
The scapula (plural 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 eithe ...
. There are two rhomboid muscles on each side of the upper back:
*
Rhomboid major muscle
The rhomboid major is a skeletal muscle on the back that connects the scapula with the vertebrae of the spinal column. In human anatomy, it acts together with the rhomboid minor to keep the scapula pressed against thoracic wall and to retract the ...
*
Rhomboid minor muscle
In human anatomy, the rhomboid minor is a small skeletal muscle on the back that connects the scapula with the vertebrae of the spinal column.
Located inferior to levator scapulae and superior to rhomboid major, it acts together with the latte ...
The large rhombus-shaped muscle, located under the
trapezius
The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula. It moves the scapula and supports the ...
muscle in the upper part of the
thoracic
The thorax or chest is a part of the anatomy of humans, 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 divisions of the crea ...
region of the back, and the small muscle, in the same way, participate in the movement of the scapula.
Anatomy
The rhomboid major muscle originates from the spinous processes of vertebrae T2–T5, while it inserts to the medial border of the scapula. The rhomboid minor muscle originates from 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 proces ...
and spinous processes of vertebrae C7–T1. Both muscles are
innervated
A nerve is an enclosed, cable-like bundle of nerve fibers (called axons) in the peripheral nervous system.
A nerve transmits electrical impulses. It is the basic unit of the peripheral nervous system. A nerve provides a common pathway for the e ...
by the
dorsal scapular nerve
The dorsal scapular nerve is a branch of the brachial plexus. It supplies rhomboid major muscle, rhomboid minor muscle, and levator scapulae muscle. It causes the scapula to be moved medially towards the vertebral column. Dorsal scapular nerve ...
, a branch of the
brachial plexus
The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th ...
. Their functions are the following:
* Drawing scapula superomedially
* Supporting scapula
* Rotating glenoid cavity inferiorly
Additional images
File:Rhomboid muscles animation small.gif, Rhomboid muscles.
File:Muscles rhomboïdes.jpg, Rhomboid muscles.
File:Gray203.png, Left scapula
The scapula (plural 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 eithe ...
. Posterior surface.
File:BodybuildingWoman.jpg, Full back muscle flex
...
References
{{DEFAULTSORT:Rhomboid Muscles
Muscles of the torso