1. Erase all doubts. "Every time [Picabo] comes in here," says orthopedic surgeon Richard Steadman, "she just will not accept the fact that she's not going to come back. With her it's always been 'when I come back,' not 'whether.'" Indeed, 90 percent of athletes who commit to their rehab protocol return to sports following ACL surgery, and many return stronger.

2. Involve yourself. "For an athlete, nothing rebuilds peace of mind like committing to the rehab protocol to the nth degree," says Damon Burton, a Sports Psychologist from the University of Idaho who has consulted with the U.S. Ski Team. Like Street, he recommends knowing every detail of your physical therapy so that when you're back at your sport again you'll know that you have cleared every physical hurdle and your focus can be on technique rather than worrying about what your body can handle.

3. Rebuild incrementally. "It's a progression," says ski coach Jim Tracy. "We don't throw Street right into another downhill." Build a foundation of ego-boosting successes by spending your first weeks back in the sport remastering the absolute basics.

4. Know when to drop the hammer. After three career-threatening crashes, Street knows when to say when. If you're not comfortable with a certain speed or technique, don't force it. "You've got to be able to categorize the task at hand, determine if you can overcome the fear," Street says. "And if you can't, walk away. Because if you don't, the fear will inhibit your chance of succeeding."

5. Find a mentor. Because U.S. Ski Team members are plagued by knee injuries, they have dozens of successful cases to call upon for inspiration. When you return to your sport, try to work out with someone who has come back from the same injury. He can help you decide when it's okay to push, and when to hold back.

6. Visualize success. After her crash, Street was tormented by nightmares. "I dreamt I'd have to stop mid-race when I hit the fast sections," she says. To overcome her subconscious fears, Street imagines herself skiing entire downhill runs in rough conditions so that even in her dreams she is winning races. Mentally rehearse the most difficult aspects of what you'll be doing, and picture yourself succeeding each time.  —C.K.