Brette Warshaw posted an excellent overview on how to reduce injury:

1. Focus On Avoiding Overuse
2. Balance Out Your Gymnasts’ Strength (reduce muscular imbalance)
3. Track Your Gymnasts’ Growth
4. Never Stop Educating Yourself & Your Fellow Coaches
5. Take Fear Out of the Equation Early On
6. Empower Your Gymnasts

Click through for specifics:

6 Ways For Gymnastics Coaches To Better Prevent Injuries

related – 5 Of The Most Common Gymnastics Injuries & How Best To Prevent Them