The teres major muscle is a muscle of the
upper limb
The upper limbs or upper extremities are the forelimbs of an upright-postured tetrapod vertebrate, extending from the scapulae and clavicles down to and including the digits, including all the musculatures and ligaments involved with the shoulde ...
. It attaches to 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 ...
and the
humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
and is one of the seven
scapulohumeral muscles. It is a thick but somewhat flattened muscle.
The teres major muscle (from Latin ''teres'', meaning "rounded") is positioned above the
latissimus dorsi muscle
The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...
and assists in the
extension
Extension, extend or extended may refer to:
Mathematics
Logic or set theory
* Axiom of extensionality
* Extensible cardinal
* Extension (model theory)
* Extension (predicate logic), the set of tuples of values that satisfy the predicate
* E ...
and
medial rotation
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relativ ...
of the
humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
. This muscle is commonly confused as a
rotator cuff
The rotator cuff is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspi ...
muscle, but it is not because it does not attach to the capsule of the
shoulder joint
The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint. ...
, unlike the
teres minor muscle
The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...
for example.
Structure
The teres major muscle originates on the dorsal surface of the
inferior angle
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 either ...
and the lower part of the
lateral border
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 either ...
of 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 ...
.
The fibers of teres major insert into the medial lip of the
intertubercular sulcus
The bicipital groove (intertubercular groove, sulcus intertubercularis) is a deep groove on the humerus that separates the greater tubercle from the lesser tubercle. It allows for the long tendon of the biceps brachii muscle to pass.
Structure ...
of the
humerus
The humerus (; ) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists of a roun ...
.
Relations
The
tendon
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability ...
, at its insertion, lies behind that of the
latissimus dorsi
The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...
, from which it is separated by a
bursa
( grc-gre, Προῦσα, Proûsa, Latin: Prusa, ota, بورسه, Arabic:بورصة) is a city in northwestern Turkey and the administrative center of Bursa Province. The fourth-most populous city in Turkey and second-most populous in the ...
, the two tendons being, however, united along their lower borders for a short distance. The fibers of these two muscles run parallel to each other, and both muscles insert at the crest of the
lesser tubercle
The lesser tubercle of the humerus, although smaller, is more prominent than the greater tubercle: it is situated in front, and is directed medially and anteriorly.
The projection of the lesser tubercle is anterior from the junction that is found ...
of the humerus (also described as the medial lip of the intertubercular sulcus).
Together with
teres minor muscle
The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...
, teres major muscle forms the
axillary space
The axillary spaces are anatomic spaces. through which axillary contents leave the axilla. They consist of the quadrangular space, triangular space, and triangular interval. It is bounded by teres major, teres minor, medial border of the hum ...
, through which several important arteries and veins pass.
Innervation
Teres major is supplied primarily by the
lower subscapular nerve
The lower subscapular nerve, also known as the inferior subscapular nerve, is the third branch of the posterior cord of the brachial plexus. It innervates the inferior portion of the subscapularis muscle and the teres major muscle.
Structure
T ...
and additionally by the
thoracodorsal nerve
The thoracodorsal nerve is a nerve present in humans and other animals, also known as the middle subscapular nerve or the long subscapular nerve. It supplies the latissimus dorsi muscle.
Structure
The thoracodorsal nerve arises from the brachial ...
(middle subscapular nerve). These are distal to the
upper subscapular nerve
The upper (superior) subscapular nerve is the first branch of the posterior cord of the brachial plexus. The upper subscapular nerve contains axons from the ventral rami of the C5 and C6 cervical spinal nerves. It innervates the superior portio ...
. These three nerves branch off the
posterior cord
The posterior cord is a part 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 ...
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 ...
. The nerves that innervate teres major consist of fibers from spinal nerves
C5-
C8.
Function
The teres major is a medial
rotator and
adductor of the humerus and assists the latissimus dorsi in drawing the previously raised humerus downwards and backwards (
extension
Extension, extend or extended may refer to:
Mathematics
Logic or set theory
* Axiom of extensionality
* Extensible cardinal
* Extension (model theory)
* Extension (predicate logic), the set of tuples of values that satisfy the predicate
* E ...
, but not
hyperextension
Motion, the process of movement, is described using specific anatomical terms. Motion includes movement of organs, joints, limbs, and specific sections of the body. The terminology used describes this motion according to its direction relative ...
). It also helps stabilise the humeral head in the
glenoid cavity
The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word ''glenoid'' is pronounced or (both are common) and is from el, gléne, "socket", reflecting the shoulder joint's ball-and-socket form. It is a sha ...
.
Injury
Isolated teres major injuries are rare. They are almost exclusively encountered in professional and high-level recreational
athletes—
baseball pitchers
Baseball is a bat-and-ball sport played between two teams of nine players each, taking turns batting and fielding. The game occurs over the course of several plays, with each play generally beginning when a player on the fielding tea ...
in particular. These injuries can be debilitating, requiring lengthy
rehabilitation
Rehabilitation or Rehab may refer to:
Health
* Rehabilitation (neuropsychology), therapy to regain or improve neurocognitive function that has been lost or diminished
* Rehabilitation (wildlife), treatment of injured wildlife so they can be retur ...
periods and missed seasons of athletics. No clear indications for
surgical treatment exist. Outcomes have been generally good after both nonoperative and operative treatment.
Additional images
File:Teres major muscle animation.gif, Position of teres major muscle (shown in red). Animation.
Image:Arm muscles back numbers.png , Muscles on the dorsum of 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 ...
, and the Triceps brachii muscle
The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates. It consists of 3 parts: the medial, lateral, and long head. It is the muscle principally responsibl ...
:
#3 latissimus dorsi muscle
The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...
#5 teres major muscle
#6 teres minor muscle
The teres minor (Latin ''teres'' meaning 'rounded') is a narrow, elongated muscle of the rotator cuff. The muscle originates from the lateral border and adjacent posterior surface of the corresponding right or left scapula and inserts at both the ...
#7 supraspinatus muscle
The supraspinatus (plural ''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 ...
#8 infraspinatus muscle
In human anatomy, the infraspinatus muscle is a thick triangular muscle, which occupies the chief part of the infraspinatous fossa.'' Gray's Anatomy'', see infobox. As one of the four muscles of the rotator cuff, the main function of the infraspi ...
#13 long head of triceps brachii muscle
The triceps, or triceps brachii (Latin for "three-headed muscle of the arm"), is a large muscle on the back of the upper limb of many vertebrates. It consists of 3 parts: the medial, lateral, and long head. It is the muscle principally responsibl ...
Image:Gray1211.png , Surface anatomy of the back. (Label for Teres major at upper right.)
Image:Gray207.png, Left humerus. Anterior view.
File:Teres major muscle.JPG, Teres major muscle
Image:Gray203.png, Left scapula. Posterior surface.
File:Slide2aaaa.JPG, Teres major muscle
See also
*
Accessory muscles of the scapula
References
External links
*
PTCentral
{{Authority control
Muscles of the upper limb
Shoulder adductors
Shoulder extensors
Shoulder medial rotators