Supination

Supination is a position of either the forearm or foot. When the arms are unbent and at the sides, the forearm is in supination when the palm faces to the front (anteriorly), or faces up. Supination in the foot occurs when a person appears "bow-legged" with their weight supported primarily on the anterior of their feet.^{[citation needed]}

The hand is supine in the anatomical position (i.e., palms facing up during autopsy). This action is performed by the Biceps brachii and the Supinator muscle.

Supination is the opposite of pronation.

History

Originally, supination of the forearm was attributed as a function of the brachioradialis muscle. However, the original idea of the biceps acting as a supinator was something hypothesised by Leonardo da Vinci, in a series of annotated drawings made between 1505 and 1510 (referred to as his Milanese period); in which the principle of the biceps as a supinator, as well as its role as a flexor to the elbow was devised. However, this function remained undiscovered by the medical community as da Vinci was not regarded as a teacher of anatomy, nor were his results publicly released.

It was not until 1713 that this movement was re-discovered by William Cheselden, and subsequently recorded for the medical community, being rewritten several times by different authors wishing to present information to different audiences. Nevertheless, the most notable recent expansion upon Cheselden's recordings was achieved by Guillaume Duchenne in 1867 in a journal named Physiology of Motion, something which to this day is one of the major references on supination action of the biceps brachii.

In running

In running, supination (also referred to as underpronation) is the insufficient inward roll of the foot after landing. This places extra stress on the foot and can result in iliotibial band syndrome of the knee, Achilles tendinitis, plantar fasciitis.^[1]

See also

• Proximal radioulnar articulation

References

External links

Look up supinate in Wiktionary, the free dictionary.

• Anatomy at Dartmouth elbow/surface/surface6
• Supination at eMedicine Dictionary
• MeSH Supination

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