Friday, November 4, 2011

Supination and Pronation of Forearm

Hello lovely folks!
Lets learn something from superior extremity.. supination and pronation!
They occur at the superior and inferior radioulnar joints
They are pivot type of synovial joints
It is the rotatory movement of forearm around a vertical axis
The axis passes from the head of the radius above to the ulnar attachment of articular disc below
The axis is not stationary because the lower end of ulna moves backwards and laterally during pronation & forwards and medially during supination

Let's consider pronation
In the movement of pronation, the head of the radius rotates within the annular ligament
Whereas the distal end of the radius with the hand moves bodily forward [pronate your hand and see]
The ulnar notch of the radius moves around the circumference of the head of ulna
In addition, the distal end of ulna moves laterally
If it didn't your hand wouldn't stay in line with the upper limb and would probably displace medially [You dont want that, trust me! :P]
Supination is the reversal of this process

We have two pronators and two supinators
Pronator teres and pronator quadratus, as the name suggests, for pronation
Supinator and Biceps Brachi for supination
[People usually forget to mention biceps brachi, which is really lame, its an important and awesome muscle!]

That's all for today
Thank you so much for reading! :)


No comments:

Post a Comment

This is express yourself space. Where you type create something beautiful! <3
Wondering what do I write? Well...
Tell us something you know better. You are a brilliant mind. Yes, you are! ^__^
Ask about something you don't understand @_@?
Compliment... Say something nice! =D
Be a good critic and correct us if something went wrong :|
Go ahead. Comment all you like here! (:

PS: We have moderated comments to reduce spam. ALL comments that are not spam will be published on the website.