Broken hand! Are there exercises that can be done to maintain upper body muscle mass while one hand is broken?

I pulled a tendon in my finger a few weeks ago and have also been doing a lot of upper body work. The short answer is: it depends. My tendon was on the end of one finger I just switched to machines and could do pretty much everything except lat pull for some reason. So it depends on where/what you broke and if you can grip anything.

You won't lose much muscle mass over only a month. But if you want to keep in the game, try some of the universal machines. Your problem is that you can't hold anything heavy or put any strain on your damaged hand, but there are ways to attach resistance to the muscle groups without picking something up. A physical therapist can suggest some alternative exercises for the arm and chest area. Ask your doctor for a referral.

just stop on both sides and resume when you are all better, the shouldn't be much, if any muscle loss