Forearm muscle exercises while lying down

Anyone know of a good forearm weight exercise to do while lying down? (For physical reasons it’s best for me not to lift weights in a standing or sitting position.)

Squeeze a tennis ball, or get a hand gripper.

Masturbation?

That’s more a bicep/shoulder exercise.
You sure as hell don’t want to squeeze too hard.

Reverse wrist curls with your arm resting on a bench, and your wrist overhanging.

This may be exactly what you’re not looking for, so apologies in advance.

Anyway, what about a wrist roller? It’s not really weight lifting per se - you hold the thing stationary and roll. You couldn’t do it laying down but you could prop your elbows on something, and you don’t have to use much weight at all to work out your forearms.

Otherwise a gripper is probably your best bet, yeah. You might be able to do a wrist curl while laying down. You take a dumbbell and just curl your wrist up and then back. Warning: I have no idea whether this would be safe in a prone position.

Get a couple of elastic or spring things you can hook somewhere down by your feet and do curls using those. If you have a bench you can do curls with dumb bells with your arms hanging over the sides.

Many sock puppets are useful in this regard. Speed not a requirement.