I'm a keen young cellist (16) with hypermobile (double jointed) thumbs and pinkie fingers. It's pretty difficult for me to maintain the correct bowhold, because the second joint of my thumb "collapses" and i sort of have to straighten the first joint to compensate. Also i tend to curl up my fourth finger when i'm not using it.
Are there exercises that i could do to strengthen the joints? And if so what are they? Any advice is much appreciated.

My bowing thumb is double jointed but I've never had a problem with it, I honestly don't know what to suggest I'm afraid. Have you asked e teacher etc.?

Hi

I'm double jointed in all my first knuckle joints, on both hands (my thumb used to bend back till it almost touched on itself). My thumb tends to do odd things around the frog, and pinkie can collapse on the tip of the bow.

I'm not aware of strengthening exercises and in my case, I've had to direct more awareness to it, I think. It's not going to go away, so my guess is you probably need to talk to your teacher about ways of working with and / or compensating for it. Hypermobile knuckles aren't that rare, so I'd guess they'll have dealt with these kinds of issues before.

Are you taking omega 3 and 6 type supplements (from flax / hemp seed oil if you're a vege, cod liver oil or similar if you're not)? I've found they've improved the overall tone of my joints considerably, and have also helped with strengthening my nails (probably not an issue for you, but as a guitarist, very important!)

righto. I'll talk to my tutor about it. thanks