Ranger17,

I have arthritis in both thumbs, so I know what you mean.

I have both a Shield 380 EZ znd a Shield 9 EZ, but you already know about them.

Here's something that hasn't been mentioned, it's called the Handi-Racker. It's a plastic 2" x 4" x 1/2" block that fits over your slide. You hold it in your palm, with or without using the thumb, and use it to push back the slide. I have two sizes. Compact works with the Shield, Full is for the bigger guns. I have both. I keep them in my range bag.

You can find it on Handi-Racker.com, they are worth the reasonable cost. Right now, they are on sale for $19.95 each. The How-To says to put it against a wall and push the gun, it works better for me to hold it in my palm and push it against the gun.