Q: Dear Eric,

I am a huge fan of yours, and a 21 year old Australian student studying exercise science. I am big fan of your Magnificient Mobility DVD, discovering it after I had written a paper on the effects of a six-week PNF stretching program. I wish I had owned your DVD earlier and used dynamic stretching as the main topic.

I fully ruptured my ACL in April and have not had an operation yet, but since then I have regained all mobility. I have not, however, done any lower body weight training apart from some calisthenics. I have been cycling to maintain some strength and whenever I ask someone they tell me to strengthen the VMO and Hamstrings, which I have also been doing. However, now I am keen to start resistance training on my legs; I did a moderate volume session last week and it was fine. I am wondering if I do strengthening exercises for my lower body such as squats, deadlifts, leg extensions, lunges, etc. and I don’t feel any pain if I am doing it any damage? Any recommendations?

A: Believe it or not, there are a lot of people – impressive athletes included – walking around with ACL tears that they don’t even know are there! Some eventually become symptomatic – possibly because of other inefficiencies – and others don’t. To that end, the best thing you can do is teach your body to move efficiently in light of the structural defect you have.

You can do posterior chain stuff like deadlifts, back extensions, pull-throughs, and glute-ham raises until you’re blue in the face; the hamstrings work synergistically to the ACL, so strengthening the hammies will help you long-term. When you optimize glute function to correct position the femur (i.e., eccentrically controlling excessive internal rotation and adduction during ordinary movements), you’re helping your cause even more.

To that end, single-leg movements are very important. Along these lines, I would start with isometric exercises (split squat isometric holds) and gradually work toward incorporating more dynamic variations, starting with reverse lunge variations and eventually progressing to walking lunges and potentially forward lunging. Luckily for you, our Magnificent Mobility DVD just so happens to be on sale through December 12 (enter coupon code HOLIDAY2007), and it would be a big help, too. There are tons of useful glute activation and frontal-plane stability drills in there.

As I have written in a previous article, leg extensions are crap for everyone:

Chow (1999) examined patellar ligament, quadriceps tendon, and patellofemoral and tibiofemoral forces at different speeds of leg extensions execution. Tibiofemoral shear forces showed that the ACL was loaded throughout the ROM — not exactly what you want (passive restraints doing the work for active restraints).

Squats variations may or may not give you trouble. I would recommend progressing from box squatting (sitting back, more hip dominant) to more quad-dominant variations.

For more information along these lines, I’d highly recommend you check out Bulletproof Knees by Mike Robertson (same holiday discount applies).

Best of luck!

Tags: ACL, Knee Injury, Magnificent Mobility