The ACL Solution by TacticalR 2 Dec 2013 13:14
As we seemed to be plagued with ACL injuries, I thought I would give this book a try:

The ACL Solution: Prevention and Recovery for Sports' Most Devastating Knee Injury
http://www.theaclsolution.com/

The author Robert Marx is an American surgeon so the book has an American emphasis. Here are some details from the book:

'There are an estimated 41 million American kids playing competitive youth sports today, and estimates run as high as 200,000 ACL surgeries per year in the U.S. alone, a large percentage of which are being performed on the knees of prepubescent kids.' The worst affected U.S. sports are soccer and basketball. According to the author this is due to the increased intensity and frequency of youth sport.

There has been a very large increase in ACL injuries among women. 'Females are as much as six times more likely to tear their ACLs than their male counterparts in the high-risk sports.'

The two main causes are what the author calls 'cutting' (turning suddenly with one foot planted on the ground, with your weight on the planted foot) and jumping. An aggravating factor is having your knee bent inward (knock-kneed position).

Most ACL injuries (about 70 percent) occur in non-contact situations.

A significant part of the book is about the anatomy of the knee. I found it hard going as I didn't know my femur (thigh bone) from my tibia (shin bone). Basically, ligaments connect bone to bone, and the ACL connects the femur to the tibia.

ACLs are slow to heal because very little blood goes to the ACL, which is bathed in a fluid inside the knee. Most athletes can't return to their sport for at least six months. An ACL injury can't normally be operated on immediately after the injury - it normally takes a month for the swelling around the knee to subside. The ACL, which may be completely broken, is normally repaired/rebuilt with tissue from the injured patient's tendons.

It's also not simply bad luck to have more than one ACL injury. Having had a previous ACL tear is a risk factor for future ACL injuries: 'if you've torn your ACL before, you are at a higher risk of tearing it again, or of injuring the other knee.'

Prevention. Studies have been done in American and Norway on reducing the risk of ACL by using ACL prevention programs. These focus on strengthening the knee and teaching players not to bend their knees inward, and to keep their knee above their toe. For example see the walking lunges exercise at 1:20

http://www.youtube.com/watch?v=7Lag8uNU6AQ