Alpine Skiing and Knee Injury

©1993 NAOC TM NAOC 7-056

Ski Injuries These Days
There is a remarkable progress of the skiing equipment in recent years. The binding has an automatic release mechanism which prevents injury when the skier falls down. Ski boots are made of hard plastic fixing the ankles firmly. Skis are designed to improve gliding and turning performance. Turning becomes easy at any situation and force from the skis is directly conveyed to the knee. As a result, the knee joint sprain is in the increase while the ankle joint sprain and the bottom thigh bone fructure that used to be major injury are now decreasung. (Fig.1)

Knee Sprain
Knee joint connects the shin bone with the thigh bone. The joint has cartlage where two bones stands against each other. It is wrapped by the joint package and inside the joint is filled with the joint liquid. The joint is supported firmly by the ligament aound the joint package. A knee joint has ligament both inside and outside of the knee. There are also anterior cross ligament and posterior cross ligament in the joint which suppor the joint firmly and stabilizie the knee movement.(Fig.2)

Cruciate Ligament Injuries
Knee strain causes injury of those ligaments. Skiing often causes the injury at the inside ligament or atbthe anterior cross ligament. Especially the number of injury in anteriorr cross ligament is on the increase reacently.(Fig.3) Advanced skiers and competitive skiers as well as recreational skiers are suffering from the anterior cross ligament injury. The ligament injury makes the knee movement unstable. It makes training difficult and discourages to enter the competition.

What Causes the Injuries?
There are four types of movement causing the anterior cross ligament injury.
  1. The knee is flexed and the foor is forced to turn outward.(Fig.4a)
  2. The foot is twisted inward.(Fig.4b)
  3. The knee joint is extreamly extended.
  4. The knee is flexed and the shin bone is pushed forward.(Fig.4c) 

Injuries During Skiing
The anterior cross ligament injury occurs not only during falling down but also during gliding. For example skier may jump and land with the body left behind. To restore the posture the anterior thigh muscle contracts strongly while the body in inclining outward . It would cause anterior cross ligament injury.(Fig.5)

Overcoming the Injuries to be Olympic Athletes

In many cases the beginners are injured during falling down but the acvanced and competitive skiers are during gliding.(Fig.6)

According to the survey conducted by a junior racing team, no ligamnet injury were reported on junior racers but two cases were found on highschool female racers during the gliding.

Development of muscle strength and changes in skiing technique may be the reason of ligament injury. Female skiers tend to experience ligament injury more than male skiers.

There were Olympic athletes who got over the ligament injury. Emi KAWABATA(Fig.7) entered the Olympic Games three times such as Calgary, Albertville, and Lillehammer. Sachi YAMAMOTO(Fig.8) also worked through the anterior cross ligament injury and entered Calgary and Albertvill Olympic Games.

In Nagano Olympic Games you may find many Olympic Athletes who have gone through the injury.

To Prevent Injuries

The progress of the sport medicine in recent years has developed a better surgical operation and a better rehabilitation. It makes us possible to go back to the former excercise level more quickly than before. However the injury damages the skiers physically and mentally. It takes a long time to go back to the competition again. Nothing is better than prevention of injury. Necessary precaution of yourself can minimize the injury though not completely.

The points to prevent skiing injury are as follows:
  1. Check your biding connecting the boot and the ski before starting to ski. The binding may be ajusted firmly for the competition and left as it was even afterward. The competitive skiers show a teneancy to tighten the binding too much. A tightening value whick is a little greater than the standard value is good enough even for the competition.
  2. Put on skis after removing the snow or mud from your boot sole.
  3. Check your physical condition and try not to overwork.
  4. Make the leg joints flexible and enhance your ability to cope with changes in the slope.
  5. Acquire the technique to keep the center of gravity always in the constant position while skiing.
Pay attention to the above instructions and enjoy skiing without inury.