Monday, 14 April 2014

Extensor Capri Ulnaris: a wrist extensor muscle

We're BACK in the forearm with EXTENSOR CARPI ULNARIS muscle!

Extensor: tells us that this muscle "extends something" as far as muscle actions go!
Carpi: refers to the WRIST Ulnaris: referring the the forearm bone: the ULNA (between the Radius & the Ulna - the ulna is on the 'pinky finger' side of the forearm.)
Attachment points:

This muscle originates at the "common extensor tendon" from the lateral epicondyle of the humerus. This area is just above the elbow and 'common extensor'  refers to the area where many of the wrist extensor muscle muscles come from.

Insertion point: Base of the 5th metacarpal (the pinky side of the wrist - the pinky is the 5th digit)

By breaking down its name,  we know that this muscle EXTENDS THE WRIST (aka - holding your hand out (palm down) and extending fingers towards ceiling - as if to say Hello!)

This muscle also helps to ADDUCT the wrist as well!
See video link for demo of muscle actions:
 Both of these actions happen at the RADIO-CARPAL joint - where the radius (other forearm bone that isn't the Ulna) and carpal (wrist) bones meet :)