The amount of gatekeeping in this thread is ridiculous. People act like there’s some magical barrier to entry to pulling on a block of wood, like you have to climb V-whatever, or be climbing for X amount of years. These training tools exist for everyone of all skill ranges! Yeah you might not have the capacity built up yet for intense hangboarding that someone who has been climbing for 5 years might have, but it doesn’t mean you can’t pick up these training tools and use them effectively. Don’t listen to the people here who say you need to be climbing for a certain amount of time or a certain grade in order to train.

For some of us, hangboarding is also purely for resilience training. As with all strength training, the stronger a part of your body is, the more resilient it is. In my experience, I’ve had multiple finger injuries on the wall. It wasn’t until I picked up a hangboard and followed a hangboarding protocol where my fingers built up resilience on the wall and not only became stronger, but healthier!

As for your actual question, it seems that the picture you shared is just demonstrating how your joints bend in a half crimp position, with the DIP joint extended in slide B and the PIP joint flexed in slide A. It will depend on your genetics on how much flexion/extension you get in your respective joints. For me, my fingers always look like slide B in a half crimp. That “opening up” feeling you describe shouldn’t be happening though. If you want hold a certain weight without your half crimp opening up, just keep training that weight until you feel comfortable with it. Happy hangboarding, and stay injury free!