In human anatomy, the deltoid tuberosity is a rough, triangular area on the antero

lateral Lateral is a geometric term of location which may refer to: Healthcare *Lateral (anatomy), an anatomical direction * Lateral cricoarytenoid muscle * Lateral release (surgery), a surgical procedure on the side of a kneecap Phonetics *Lateral co ...

(front-side) surface of the middle of the humerus. It is a site of attachment of

deltoid muscle 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 appears to be made up o ...

Structure

Variation

The deltoid tuberosity has been reported as very prominent in less than 10% of people.

Development

The deltoid tuberosity develops through endochondral ossification in a two-phase process. The initiating signal is tendon-dependent, whilst the growth phase is muscle-dependent.

Clinical significance

The deltoid tuberosity is at risk of avulsion fracture. These fractures may be managed conservatively with rest.

Other animals

In mammals, the humerus displays a wide morphological variation. The size and orientation of its functionally important features, including the deltoid tubercle, greater tubercle, and medial epicondyle, are pivotal to an animal's style of locomotion and habitat. In cursorial (running) animals such as the

pronghorn The pronghorn (, ) (''Antilocapra americana'') is a species of artiodactyl (even-toed, hoofed) mammal indigenous to interior western and central North America. Though not an antelope, it is known colloquially in North America as the American a ...

, the deltoid tubercle is located about a quarter of the way down the shaft, which allows for rapid but relatively weak limb flexion and extension. In natatorial (swimming) animals such as the

North American river otter The North American river otter (''Lontra canadensis''), also known as the northern river otter and river otter, is a semiaquatic mammal that only lives on the North American continent, along its waterways and coasts. An adult North American rive ...

, the tubercle is located nearly halfway down the shaft, which allows for powerful limb flexion and extension. The tuberosity can be very pronounced in fossorial (digging) animals, such as the mountain beaver. (Including an illustration of variation in mammalian humeri.) It is very superficial in horses.

References

{{DEFAULTSORT:Deltoid Tuberosity Bones of the upper limb Humerus