Thumb: 2 knuckles or 3?

[Muse]

So, doing some research on the pain I have in my hand yesterday one of the expert sites stated that fingers have 3 knuckles but the thumb just 2. I looked at my hand and went, yeah, guess so. But today I'm thinking otherwise. The 2nd knuckle of my thumb is at the top of a bone that is about 2 inches long and pivots at the base. That base is, evidently another knuckle. The bottom knuckle of each finger doesn't just bend in one plane like the higher knuckles -- it rotates in a manner similar to the shoulder (but with less arc). The 3rd "knuckle" on my thumb similarly has rotation, so it's a knuckle just like the 3rd knuckle of the fingers.

Am I right here? I have very inconsistent, sometimes very sharp pain kind of out of the blue at that "knuckle." I'm trying to figure it out.

 

[pcgeek11]

I think that "third" knuckle would be classified as part of the wrist.

 

[Muse]

I think that "third" knuckle would be classified as part of the wrist.

Yeah, it's at the wrist but seems to me that it could be thought of as the 3rd knuckle of the thumb. I'm wondering if the distinction has and real significance. Examining my thumb I'm inclined to think that the thumb should be regarded as a 3 knuckle affair.

The problem I alluded to is in my left wrist where it joins the thumb, but other than the base of the thumb, the wrist seems normal to me.

 

[pcgeek11]

If you count that third thumb joint as a knuckle then the fingers would have four knuckles.

 

[Muse]

If you count that third thumb joint as a knuckle then the fingers would have four knuckles.

Well, doesn't seem like that to me. The bottom knuckle for the fingers, if you call it that, doesn't rotate, it's just part of the wrist. Well, I can see what you're saying. The fingers all (with the palm) rotate together when you rotate the wrist. But the thumb moves independently at its bottom from the fingers/wrist.

 

[pcgeek11]

I guess it is one of those grey areas.

 

[Muse]

I guess it is one of those grey areas.

That's kinda what I'm thinking. Thanks.

Edit: Here's Wikipedia's page on the bones of the hands and feet

 

[shortylickens]

you're born with two hundred and forty.
They fuse into two hundred and seven.