Wow, it was great to see Ernie Els up on top of the leaderboard. He has not won on the PGA Tour in nearly 3 years, and he has struggled to get his old form back since knee surgery in 2005. Ernie tore his ACL while on vacation (Golf Digest reported he was inner tubing) so he probably twisted the wrong way and it snapped. It hurts me just writing "snapped!"

I know Ernie worked really hard on rehabbing the knee and getting back into shape. Too bad he didn't pull it off.

Among other things, having strong glutes(particularly the Glute Medius) and single leg strength are good ways to decrease your potential of injuring your knee.

Here are 2 exercises you are probably not doing that you should be adding to your program:

Glute Medius Activation- the Glute Medius is a stabilizer of the pelvis, which will help keep the knee in line. The Glute Medius also helps the back leg stay stable throughout the backswing, important for developing the X-Factor and keep you from swaying. Equally important, it will help to keep you from sliding on the follow through.

With a band around your ankles and standing in address position, step to the side for 10 paces. Keep your feet wide apart and only move from the hips, do not move your torso. You should be in the address position the whole time. Repeat the other way. You should feel a burn on the side of your butt.

Single Leg Squats- This exercise will help develop good single leg strength and stability throughout the swing as well.

Standing on 1 foot with your arms out in front of a bench, slowly lower yourself to the bench. Do not crash down and try not to let the knee move around too much. If the bench is too low, put something on it to make it easier.

As always, if it hurts, don't do it. Have a trainer check your form to make sure you are doing it right.

For more information on knee pain and how to prevent it, check out Michael Boyle's article, "Anterior Knee Pain"