Do you have opposable thumbs?

You’d think that after 40+ years of life, there wouldn’t be a lot of undiscovered territory on body parts in as frequent use as my hands, but yesterday I discovered that I’m some kind of freakish throwback - don’t have fully opposable thumbs. :eek:

I’ve got quite stumpy, sausagy hands anyway, but I have no mobility at all of the joint between the metacarpal and phalange in both thumbs (yellow and green in the diagram on thispage). Never had.

If I bring my thumb inward across my palm to the fullest extent possible, I can’t reach as far as the base of my little(=pinky) finger, or oppose my thumb (either hand) against its tip. As a child, I couldn’t do the cub scout salute.

But I didn’t realise until yesterday that it’s because there’s essentially no joint at the base of my thumb - I discovered it by comparing my hands to my daughter’s (who does not appear to have inherited my style of hand). When she brings her thumb fully inboard, there is a distinct and angularly protruding knuckle at the base of her thumb - when I do it, all that happens is my palm tries to fold inward.

Is this common? Do you have it? Do you have stumpy hands too?

Have you ever had trouble playing a musical instrument?

I’ll never be a concert pianist, for sure.

I don’t really play much beyond blues harmonica, but I certainly found guitar (trying to finger the chords) uncomfortable to the point of impossibility. I tried learning keyboard once too, but my fingers are too short for full sized keys and too thick for three quarter or half sized.

That’ll be your Neanderthal DNA.

Win.

I’m surprised you can even type. How do you hit the space bar?

I have stubby fingers too, but at least my thumbs work. But back when I played violin I sometimes had to get my fingers really close together on adjacent strings, and it wasn’t easy.

I can’t really move it by itself, but I can bend it down with my other hand. It also folds over when I “palm” my thumb. So yeah, I’m normal.

Th-umb?

Wait, how many fingers do the rest of you have?

With my thumbs. They’re not immobile, they just don’t bend at the joint nearest where they appear to diverge from the palm - the still hinge at the metacarpal and have two and a bit degrees of freedom in the joint that’s buried within the heel of the palm.

Here are some photos illustrating the problem:

1 - fingers extended, problem joint indicated with an arrow

2 - end joint bent

3 - palm joint bent

4 - thumb bent inward as far as possible

(NB: there’s a bit of foreshortening in these images that makes my hands look slightly more stumpy than they in fact are)

My hands are very similar to yours but I don’t this problem. In fact, I have more mobility on my left thumb than normal. I know this because my right thumb doesn’t have as much mobility. I have an explanation but it’s a dumb one and I don’t believe it. I’m right handed in case you were wondering.

Do you have hairy palms as well?

My hands are normal. You would have a tough time playing the violin with that thumb not reaching your pinky. I’m glad your daughters ok. Don’t feel bad I have one leg slightly shorter then the other and didn’t find out till my 30’s. Unfortunately my daughter inherited it. My Mom has it too.

I’m glad I have fleet fingers (so is my girlfriend) or I couldn’t play ukulele like I do. But I’ve seen guys with great big sausage fingers play ukulele like balls o’ fire. How do they do that? I play a baritone, BTW, the king of ukuleles.

My hands are normal, but my sister has stumpy thumbs - her last digit (on both hands) is pretty stubby and looks like a toe. Doesn’t seem to affect her in any way though, she types fine and played the flute and french horn in high school.

I have double-jointed thumbs - funny story, I didn’t know that everyone couldn’t pop their thumb backwards until I started taking martial arts in high school. We were doing some grappling exercise, and I asked the teacher if my thumb was supposed to be all the way back like that, and he freaked out because he thought it was broken.

No, just the tongue.

I wonder if you have an over-tight tendon in there somewhere - I have the opposite issue, hypermobile joints. My son and daughter complain about my genes (they complain about my jeans as well, but they have no sense of style) as they both have joint issues - my daughter has wrist, knee and jaw problems, my son pops his shoulder like his dear old dad.

You may be able to work on it a bit - maybe try a Powerball - if you hold it using your fingertips (rather than in the palm of your hand) it really works the finger and thumb actuators, plus your whole wrist. Otherwise, regular stretching, like any tight tendon.

Si

It’s possible - I can make the joint flex about 10 degrees if I apply external force, but it feels locked solid - the same sort of sensation as you get if you try to bend any normal finger joint backwards.

My sister and both of my kids have ‘trigger thumbs’ that required operations to free up - which is a tendon-related thing - so maybe it’s something in the genes.

And you collect…photos of lost gloves, yes?

  • pondering *