Given that there are no muscles in the fingers, how is it that people who work with their hands have big fingers? For instance, my father in law is a farmer of short stature but his hands and fingers are large (and rock hard). What is the mechanism that makes them grow?
Bigger/stronger tendons and calluses, maybe?
Could you please source that statement? I know that closing fingers uses tendons that are pulled by forearm muscles via the carpal tunnel in the wrist, but opening may use other muscles in the hand. Looking at my hands right now – what would my fingers be made of? Yes, bone and skin and sub-cutaneous fat and blood vessels but … thay’d be really empty skin sacs of vessely bone without musculature.
Do you really believe so?
Fingers lack skeletal muscles, it’s true. All the necessary muscles are in the forearms and hand itself, proximal to the first knuckles (MCPs). They do have muscle fibers that are attached to the hairs of the fingers, and can cause the hairs to stand up. But that’s true for anywhere on the body there is hair.
Here’s a decent representation of the anatomy of the hand, as far as bones, tendons and muscles go: https://www.pinterest.com/pin/440649144766126263/
AS for the OP, well, some folks just have big fingers. Excessive use won’t necessarily make them bigger, just more dextrous. Pianists don’t develop huge fingers from playing keyboard all the time, after all.
Did you see his fingers before he was a farmer? Did his father have big fingers?
No. But I know that he has outgrown 3 wedding rings throughout his life and his weight has remained more or less constant (150 pounds). His father was also a short farmer with powerful hands.
But pianists don’t exert much force with their fingers, while farmers do.
Weightlifters and bodybuilders develop very thick fingers.
My high school biology teacher once told us that if you exert physical stress perpendicular to a bone, it will adapt by bending; if you exert physical stress in a direction antagonistic to a muscle, it will adapt by growing stronger; if you exert physical stress on the surface of skin tissue, it will adapt by thickening.
The overall size of my hands aren’t that much larger than my girlfriend’s (she has small girl hands and i have extremely small man hands). However, after using my hands for everything functional in my life-i use a wheelchair-and being a weightlifter and bodybuilder for many years as well, my joints have thickened significantly. The few muscles in the hand that control the fingers and thumb (especially the muscle that controls the thumb) have beefed up. I can actually flex my thumb muscle and make it tight like an ass you can bounce a quarter off of.
My fingers have thickened with age. Part of it seems to be arthritis.
I’ve heard anecdotally that rock-climbing can result in increased finger thickness. From the 2006 paper “Factors influencing osteological changes in the hands and fingers of rock climbers” it appears to be at leasty partially due to bone growth:
The relationship between measures of bone thickness and sport climbing and bouldering, and not traditional climbing or years of climbing, indicate that bone remodels to accommodate high-intensity mechanical stress and not to frequent low-intensity stresses, even if maintained over long periods of time. The results also suggest that it is possible for adults to deposit new bone subperiosteally, even if they have already reached skeletal maturity.
There’s a discussion about it here.
I’d WAG a growth in skin thickness and bone thickness due to lifting more weight, and body fat.
The males in my family were comparing hand sizes last year because we were playing with my dad’s new set of sports balls.
My dad and I almost the same height, we have the same body type, and we both have desk jobs: we have skinny fingers with knobby knuckles.
My brothers are half a head taller than me, outweigh me by about 100 pounds, and are contractors/builders. They both have fat hands with fat fingers, albeit their hands are smaller than mine.
Bones can change and grow according to activity.
Do they have bigger fingers? I took to Google after reading this thread because I’d never heard of this correlation, and I haven’t been able to find any statistics on this.
Sorry. I only have access to anecdotal data. I know of no scientific studies.
I believe there was a reference above, but I don’t find it, to the question, “What are fingers made of if not muscle?” I tore a hole in my knuckle at work, and there is pink stuff in there that looks like the pink stuff I see elsewhere when I injure myself.
Not a normal condition, but there’s always elephantiasis. I had a physics teacher once with minor symptoms of this in his hands and face.
If you work with your hands a lot
Thickening of skin (calluses)
Thickening of joints or swelling of them
Thickening of tendons
Also thickening due to injury/damage, scaring, arthritis, etc.
No muscle though, it would be ill suited to be in a finger, not enough space to fit the strength needed, look at what your fingers are capable of holding, your entire body in some cases.
Youd really have some fat meaty fingers if they were full of muscle.
BUT what is that pink, bleeding stuff that I see when I so often hurt myself?!?!