In today’s post, I’m going to discuss a very common ski injury, the ACL tear. The ACL (anterior cruciate ligament) is a rope like structure in the knee that stops the shin bone (tibia) from sliding forward on the thigh bone (femur). Like any rope, while it can resist an awful lot of force, it’s by no means invincible and will, under enough force directed in the right direction, incur damage and even rupture completely.
It’s the “right direction” part of that force that we’re most interested in. Research suggests that amongst recreational skiers, the most common (but not the only) mechanism of injury to the ACL is the “sit back fall”. In this action, the skier collapses backward so that they are essentially sitting on the rear portion of their skis. In the video my friend and physio classmate Erin Campbell demonstrates this type of fall. This action forces the knees into maximal flexion with an internal rotation of the shin on the thigh. Anatomically speaking this is a fantastic way to stress the ACL, and if performed with enough force (not difficult in skiing) will damage that structure. This is no fun for anybody.
To avoid this injury pattern, try to focus on two simple tips. First, avoid “sitting back” in your boots with your center of mass behind your feet. Try to assume a more aggressive forward posture with your center of mass squarely over your feet and your upper body pointing down the hill. This will reduce the likelihood of your falling backwards when the going gets tough, and will make you a more stylish skier to boot. Second, if you are uncomfortable assuming a more aggressive posture in the terrain in which you are skiing, find new terrain to ski in. Staying in control with good form isn’t just the healthy and safe way to ski, it’s also more fun! Skiing well in terrain that’s on the safe side of challenging will help to boost your confidence and will force you into good habits that will serve you well as you develop your abilities on the hill. So have fun, ski with style in terrain suited to your level!