Step I finger flexion anatomy question

[Ramoray]

this probably is not much signifigance for step 1 but as i am studying i remmeber i had the same question when i was taking anatomy and i am just kind of curious in something like clawhand from an ulnar nerve injury tyipcally it says you lose flexion of the last 2 fingers at the metacarpel phalangeal joints. But the FDS also flexes those same joints and it is supposedly its strongest action so im curious as to which muscles take priority.. the intrinsic hand muscles or the larger flexors. I dont see why MP joint flexion wouldnt be fine as long as you had the FDS in tact? just more curious thanks!

 

[Idiopathic]

It still flexes, but its attachment site is such that it will only flex the first two joints, and not the DIP. Remember, the FDP attaches to the end of the distal phalanx, and is what makes a fist. If only FDS is intact, then you can flex everything but the DIP, and you make the 'claw hand'.

 

[Su4n2]

idio, u better stick your head into this forum often next year and be there for us 2007 folks. u are like consulting a quick reference....

 

[Idiopathic]

Actually, isnt this 'ape hand'? I thought clawhand was when you tried to extend the digits and you cant extend the DIP...its been awhile. I am sure about the attachment sites, but not about the specific lesions.

 

[bigfrank]

This is explained REALLY well in HY Anatomy. If you have the book, which I assume you do, look it up in there. It really made sense to me, shows pictures, etc.

 

[Ramoray]

thanks guys, ya its claw hand and HY is great i guess its just inherently hard to understand the exact role of how powerful each flexor but yes makes sense!

 

[undecided05]

Not being able to extend the DIP's is also known as Mallet Finger. It usually happens with trauma to the DIP though.

 

[Mossjoh]

Are you referring to the "bishop's sign" of ulnar nerve palsy?

Mossjoh