Skiing season is upon us! But while there is plenty of reason to rush off to the slopes, it is a good idea to talk a little about some of the injury risks associated with skiing. This article will focus on knee injuries. Specifically, the dreaded anterior cruciate ligament (ACL) tear, or the “mother of all knee injuries” as I call it. ACL tears occur when the tibia (shin bone) shifts forward on the femur (thigh bone) to a point where the ligament cannot withstand the force. Anyone who has had an ACL tear knows how long of a rehab process it is to get back to sport, which is why it is important to look at ways to try to prevent this from occurring.
ACL tears in skiing can come about from a variety of different mechanisms. A few of the common and more significant ones are listed below:
Valgus/Tibial external rotation
“Valgus” refers to when the knee drifts towards the midline of the body (e.g., the right knee moving towards the left). This can happen to the knee when catching the inside edge of the ski tip in the snow. It causes an outward rotation of the tibia, while the body’s momentum is carried forward.
Hyperextension refers to when the knee is straightened beyond its normal capacity, such that it goes backwards. This happens in skiing when the front of the skis are suddenly stopped (as when hitting some heavy snow) and the body’s momentum is carried over top of the tibia.
This injury occurs when landing from a jump and the back of the ski contacts the ground first. As the bodyweight shifts backwards, the lower leg comes forward, attached to the ski via the boot and bindings. This pulls the upper portion of the tibia forward, stressing the ACL.
This is the most common mechanism for ACL injury in recreational skiers. It happens when you fall backwards such that your butt ends up below the level of your knees while falling to one side.
Although there are no absolute ways to prevent ACL tears in skiing, listed below are some exercises to try, based on the different mechanisms of injury:
Reverse lunge holding onto a countertop
Holding onto a sturdy object like a countertop, step back with one leg and lower your knee towards the ground as slowly as you can. This might mean holding on quite tightly to the countertop. From there, you can use both arms and legs to come back to standing. The focus is on slowly lowering to the ground. I often cue people to try to keep their front knee towards the outside toes when lowering the back knee to the ground.
This is a specific lifting technique wherein you maintain fairly straight knees while bending your upper body forward, making sure to hinge from the hips. A cue I often give people is to push your butt back and keep your weight closer to your heels. You should feel your hamstring muscles get tight and engage.
This exercise involves a band around your ankle (e.g., the left ankle) attached to a stationary object on the other side of your body (to the right). Keeping the right foot facing forward and the knee slightly bent, slowly kick the left leg out in front of you. This will create a pull from the band across your body. Following this, step over the band with your right foot try kicking the left leg backwards. Note: going backwards is considerably harder! The band will create a torque force at the knee, and the stronger you become at resisting rotation forces, the better off you are to prevent rotational knee injuries.
Keep in mind that these exercises can be taxing on the muscles, and therefore should not be performed two days in a row. As a general recommendation, I would suggest going through a small range of motion with each exercise to get a feel for things before progressing along. Each of these exercises can present a risk of injury if done incorrectly, so it is strongly advised to have a rehabilitation professional view your form and guide you through. Sometimes slight modifications can make a big difference to an exercise.
I hope that this article serves as a useful guide to preventing not only ACL but other injuries during your skiing season. Whether you have an injury or simply want to check in with someone to ensure you are safe on the ski hill, book an appointment with one of our highly skilled physiotherapists at Allan McGavin, and we will set you in the right direction!
If you have any questions, please feel free to contact me:
Shea, K.G., Archibald-Seiffer, N., Murdock, E., Grimm, N. L., Jacobs, J. C., Willick, S., & Houten, H. V. (2014). Knee Injuries in Downhill Skiers. Orthopaedic Journal of Sports Medicine, 2(1), 1-6.