Palmar interossei muscle during crimping

I’m currently training hangboarding, and have noticed that my 3 finger drag is a lot stronger than other holds. Been going hard on full crimp and half-crimp lately. I kind of tweaked my middle finger early last week. Thankfully, I didn’t keep going through the pain, and through gradual loading over the past few days it’s already feeling much better.

But, all this extra time experimenting with different finger positions made me notice something.

The palmar interossei muscle on the index finger of my left hand doesn’t engage when I half-crimp, while it does on my right hand. The result is that my index finger rolls away from the middle finger leaving a bit of a gap when I’m half crimping. And I think that allowed my middle finger to roll towards my index finger during hangboarding, which caused my injury.

Anyway, now I’m trying to compare the two hands. My right hand definitely feels a lot more stable, as all of the fingers are squeezing tight against each other. I feel like I should train my left hand to do the same. I guess I can do it by holding a rubber band with my right hand, and squeezing my index finger towards my ring finger while in a half-crimp position. Or just do it isometrically, by consciously doing a maximal contraction when the PIP joints are pressing against each other.

I’m kind of excited! Anyone else play around with this? A brief internet search didn’t turn up much, other than this post by Jared Vagy: Login • Instagram

Do you squeeze your fingers together when you do a maximal half-crimp?

Figured a picture is worth a thousand words:

Jared Vagy talks about it in the nugget climbing podcast: EP 122: Jared Vagy — How to Prevent Knee, Shoulder, Elbow, and Finger Injuries as Climbers — The Nugget Climbing Podcast

And I think that instagram post shows the exercise that he recommends. It’s quite interesting, never thought of finger stabilisation muscles before.

Out of curiosity @dddddddd is most of your climbing indoors? Time spent climbing vs. hanging?

Only curious because outdoors holds are rarely flat and even, and will often force your fingers into positions in which keeping them together isn’t even possible.

I’d say I climb about 6 hours a week, and hangboard maybe 45 minutes. My climbing is 90% indoors. So I spend most of my time on plastic.

I think that it’s likely that I’m not engaging that muscle even if my fingers are placed unevenly. So maybe practicing that engagement will help generate more tension in the palm even on other kinds of holds?

Maybe so. One of the problems with indoor climbing is that we just don’t often need to split the fingers up. Outdoors it’s the norm in many areas. So you’re probably adapting to indoor climbing like most folks do.

Not a bad idea, really, if you’re also planning to go outside. If you’re primarily an indoor climber, it’s probably a rare occurrence.

I’m guessing here of course, and I’m also not generally a fan of worrying too much about strengthening individual things that aren’t getting used often while doing the sport - but if you have the time it can’t hurt.