A grapplearts reader writes:
Q: How can I still train if I have an injured hand, wrist, arm or shoulder?
A: Being injured is super-frustrating when you want to train. But there are things you can do to keep your skills sharp even if you’ve got an upper body injury…
One great drill to do (whether you are injured or not) is the ‘Two Legs, One Arm Drill”. Start with a partner. Both you and your partner grab your own belts (or waistband of your shorts) with one hand, effectively taking one arm out of play. Now you start with one person in the open guard trying to pass: he can stand or kneel as he wishes.
The other person defends using one arm, both legs and hip movement; if he can pull off a sweep, so much the better! If one person passes the guard both people stop, go back into the guard, and start again.
I have used this drill while injured on a number of occasions, and every time the leg agility and open guard defense have improved noticeably. The hard part is not letting go of your belt while scrambling, but this is critical to the drill.
In addition to this drill, I would suggest that you do whatever you can on the conditioning front. Can you still run? Go on the stairmaster? Weight train your legs and core?
Drilling your legwork and working on your conditioning will totally pay off when your injury heals and you are ready to go 100% on the mats again.