Anterior knee laxity in skiers before and after racing

Nineteen top-level local skiers were measured for anterior knee laxity using a commercial knee laxity testing device, the Medmetric knee arthrometer model KT-1000. There were 7 women and 12 men; their average age was 27.1 years, with the ages ranging from 22 to 36 years. Six recreational skiers, 4 women and 2 men (average age 26.6 years), were measured before and after two periods of free skiing for 2 h each for control. According to statistical analysis, anterior knee laxity significantly increased after racing activity. The post-race measurement of anterior laxities showed that 2 of the skiers had a ruptured anterior cruciate ligament (ACL). The histological findings regarding the ruptured ACL revealed waving of the collagen fiber and remodeled ACL collagen fiber. We suspect that the excessive stress on the knee caused by quadriceps contraction may weaken the ligamentous tensile property.