The snow has finally arrived and all types of skiers, from the recreational to the avid, are preparing to hit the slopes. There is excitement and fun that fills most experiences. Unfortunately, injuries do occur and typically it is not thought about until it becomes a reality.
The Medial Collateral Ligament (MCL) is the most common ski injury. This is a ligament that often heals well without surgery. Typically, a brace and physical therapy is the preferred treatment. The Anterior Cruciate Ligament (ACL) tear is the more high profile injury because it often requires surgery. The ACL is an important ligament that is responsible for the central stability of the knee.
There are three types of spills during skiing that can tear your ACL. The most common way is a forward fall, where the front inner edge of the ski engages the snow. The skier is propelled forward and the leg is rotated outward in relation to the thigh. The torque on the knee is significantly magnified because of the long ski and a tear may occur. It seems more likely to tear the ACL when the skis do not disengage during a fall.
The next type of mechanism of tearing the ACL during skiing is BOOT induced. This happens when the top of the back portion of the boot pushes the tibia (lower leg bone) forward away from the femur (large bone above the knee). This causes a separation of the knee bones and a subsequent stretching and tearing of the centrally located ACL.
Lastly, the third way of tearing your ACL is when the skier is positioned back on the skies, loses balance and sits far backwards. Then suddenly, the inside edge of the back of the ski catches the snow producing a sudden internal rotation of the flexed knee and, thus, tearing of the ACL.
Ladies have a higher incidence of tearing their ACL. This is due to neuro-muscular forces where ladies' landing is more quadriceps dominant and in greater extension. There has also been a genetic correlation where the COL5A1 gene was associated with a lower risk of ACL tears in women. Other risk factors include an increased BMI (body mass index) and joint laxity ("loose joints" or very flexible). Moreover, the installment, adjustment and inspection of the ski's binding is very important. A higher rate of lower leg injuries in skiers has been shown when their equipment was not checked to meet standards for function and calibration. So, make sure you get your skis checked regularly.
So, how can we prevent ACL tears? Well, muscular training for ladies that focuses on increased hamstring strengthening and landing in a more flexed position has shown to be effective in preventing ACL injury. In addition, skier awareness training has been effective; one study showed a decrease in ACL injuries among ski patrollers after they viewed an ACL awareness and training video. Another method of potentially preventing an ACL tear for both men and women is to use a short ski. This diminishes the torque in case of a spill. Lastly, there is no evidence to show that an ACL brace is effective in preventing a tear. Nonetheless, it has been effective for support in those that already tore their ACL in the past.
Ski season is here and this the time that millions of people look forward all year round. Make sure to take all safety precautions and have a great time!