Yes, you read that correctly, training with a hurt arm can be good thing.
Emphasis on the word “can” or course. Obviously you always want to consult a doctor before you train with any type of injury.
However, assuming it is just a minor injury, training is not only safe, but can help your jiu-jitsu.
“Training one arm is a good practice anyway because what it does is it handicaps yourself and forces you to figure out solutions to being handicapped,” said Kama’s Jiu-Jitsu’s Ryan Young.
Young suggests putting your arm inside of your belt and holding on to it, as this well help keep your arm close to your body. It will also prevent people from arm barring you and further injuring your arm.