The purpose of this study was to estimate cruciate ligament forces in Alpine skiing during a movement that has been associated with anterior cruciate ligament (ACL) tears. Resultant knee joint forces and moments were obtained from two skiers during a World Cup Downhill race using an inverse dynamics approach and a 2-D bilaterally symmetric system model. It was found that ACL forces were typically small for both skiers throughout the movement analyzed because quadriceps forces prevented anterior displacement of the tibia relative to the femur at the knee joint angles observed. However, for about 10 ms, loading conditions in the knee joint of Subject 2 (who displayed poor form) were such that large ACL forces may have been present. These particular loading conditions were never observed in Subject 1, who displayed good form. Since neither of the skiers was injured, it is not possible to draw firm conclusions about isolated ACL tears in Alpine skiing from the data at hand.
Walter Herzog and Lynda Read
Lynda Read and Walter Herzog
The purpose of this study was to determine resultant knee joint forces and moments during a specific movement in Alpine ski racers. The movement analyzed consisted of a landing from a bump and the initiation of recovery (if necessary). Resultant loads were obtained using an inverse dynamics approach. Results of two specific skiers are contrasted, one skier landing in good form, the second skier landing in poor form. The skier landing in poor form exhibited larger knee flexion, and larger knee joint resultant forces and moments than the skier landing in good form. The movement of the skier landing in poor form has been associated with isolated anterior cruciate ligament (ACL) injury. However, the data obtained in this study do not indicate that either skier was in danger of ACL injury.