Deltoid muscle

Deltoid muscle
Deltoid muscle
Muscles connecting the upper extremity to the vertebral column
Details
Origin	The anterior border and upper surface of the lateral third of the clavicle, acromion, spine of the scapula
Insertion	Deltoid tuberosity of humerus
Artery	Thoracoacromial artery, anterior and posterior humeral circumflex artery
Nerve	Axillary nerve
Actions	Shoulder abduction, flexion and extension
Antagonist	Latissimus dorsi
Identifiers
Latin	musculus deltoideus
MeSH	D057645
TA98	A04.6.02.002
TA2	2452
FMA	32521
Anatomical terms of muscle [edit on Wikidata]

The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle is made up of three distinct sets of muscle fibers, namely the

1. anterior or clavicular part (pars clavicularis)
2. posterior or scapular part (pars scapularis)
3. intermediate or acromial part (pars acromialis)

The deltoid's fibres are multipennate. However, electromyography suggests that it consists of at least seven groups that can be independently coordinated by the nervous system.^[1]

It was previously called the deltoideus (plural deltoidei) and the name is still used by some anatomists. It is called so because it is in the shape of the Greek capital letter delta (Δ). Deltoid is also further shortened in slang as "delt".

A study of 30 shoulders revealed an average mass of 191.9 grams (6.77 oz) in humans, ranging from 84 grams (3.0 oz) to 366 grams (12.9 oz).^[2]