Why do our thumbs have one less joint than our other fingers?

furie27

Senior member
Apr 22, 2004
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There is a third joint, it's located right above the wrist. It's the joint that makes our thumbs opposable. Dr. explained it to me when I broke my hand in the 4th grade.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
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Originally posted by: furie27
There is a third joint, it's located right above the wrist. It's the joint that makes our thumbs opposable. Dr. explained it to me when I broke my hand in the 4th grade.
Exactly. It's just that there's a large amount of, for lack of a better term, "webbing" between the thumb and the index finger.

ZV
 

Stunt

Diamond Member
Jul 17, 2002
9,717
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Because you touch yourself at night...

And you are wrong, it does have the same amount of joints.
the ball of your fingers are at your knuckle and you have two joints till the tip of the finger...
now check your thumd, the ball is at your wrist, still has motion (try by hold thumb stiff and straight, you can still move it)
then you again have two joints till the end, one right by the start of your hand, and one on the thumb.

So technically same number of joints...
 

Yossarian

Lifer
Dec 26, 2000
18,010
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"Why does our thumbs have one less joint than our other fingers?"

and that's edited for grammar eh? ;)
 

b0mbrman

Lifer
Jun 1, 2001
29,470
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Originally posted by: furie27
There is a third joint, it's located right above the wrist. It's the joint that makes our thumbs opposable. Dr. explained it to me when I broke my hand in the 4th grade.
Yup
 

her209

No Lifer
Oct 11, 2000
56,336
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Originally posted by: Yossarian
"Why does our thumbs have one less joint than our other fingers?"

and that's edited for grammar eh? ;)
Hey now, I just got up!
 

djheater

Lifer
Mar 19, 2001
14,637
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Originally posted by: her209
Originally posted by: furie27
There is a third joint, it's located right above the wrist. It's the joint that makes our thumbs opposable. Dr. explained it to me when I broke my hand in the 4th grade.
http://education.yahoo.com/reference/gray/subjects/subject?id=56

In the four fingers the phalanges of the first row articulate with those of the second row and with the metacarpals; the phalanges of the second row with those of the first and third rows, and the ungual phalanges with those of the second row. In the thumb, which has only two phalanges, the first phalanx articulates by its proximal extremity with the metacarpal bone and by its distal with the ungual phalanx.

:thumbsup:
 

furie27

Senior member
Apr 22, 2004
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