Does tapping your fingernails on a hard surface make them grow faster?

Factual Questions
1

For nearly all of the first 40 years of my life, I had the habit of biting my nails. I’ve stopped now for just over a year (I don’t think they’ll ever quite return to normal though, because of the damage of so many years’ severe cropping - the nail beds themselves are quite short).

Anyway… I have recently acquired a new habit - one that I didn’t realise I was doing until someone commented on it. I’ve been tapping/drumming the fingernails of my middle two fingers of my right hand on the desk while thinking about stuff at work.

I happened to notice that the nails on those two fingers are longer than all the others - not only that, but they’re uneven - because the nail beds appear to be longer (that is, extend further) on one side of each of the two fingers - the side that bears most of the impact, due to the slight tilt of my hand when tapping.

So… I did already google this, and did find a number of sites where it was claimed that tapping the fingernails on a hard surface can encourage them to grow faster/stronger, but none of these sites quite seemed to cut the mustard, in terms of academic rigour.

They do argue some not-implausible mechanisms (mostly increase of blood flow), and I think I remember reading about some other experiments relating to vibration causing accelerated growth (in plants, I think).

So what I’m looking for is the serious answer to this - does anyone know if there has been any proper research into this topic?

2

I’m afraid I have no cite, but I have heard that vibration can encourage bone growth. Could that be related? I’m thinking it’d have to be a whole lot of tapping though…

3

I have no cite that I can link to online, but I read in the Encyclopaedia Britannica Yearbook of Health and Medicine* (1983?), that the hair and nails respond to mechanical stress (tugging, pulling, striking, etc.) by growing faster and thicker. So working with your hands can strengthen your nails, brushing your hair can make it thicker and stronger**, shaving can make your beard grow in more heavily, etc.

Basically, anytime you put a strain on the nailbeds or hair follicles, your body responds by making those parts grow faster and stronger, similar to the way that callouses are formed.

*I could be misremembering the title, but it’s close to that.

**Brushing also helps by distributing natural oils along the length of your hair to protect it from drying out and becoming brittle.

4

When I was young I had once read that people (OK back then the article said women) who used type writers had more fingernail growth than those who didn’t.