Incidence Of Anterior Cruciate Ligament Injuries Research Articles

Knee Muscle Strength in Elite Male Gymnasts

This study was launched to establish the profile of knee dynamic concentric strength in elite male gymnasts after it was found that three of the 10-member Canadian men's gymnastics team had incurred anterior cruciate ligament (ACL) rupture. The dynamic concentric force characteristics of the quadriceps and hamstring muscles of 84 male gymnasts were studied at the Canadian National Championships using a Kin-Com isokinetic dynamometer. These tests were performed at 90 degrees/sec and 230 degrees/sec and revealed that the hamstrings to quadriceps peak torque ratio was not only unusually low (0.5) when compared with data collected in previous research, but that this ratio was consistent across all ages, from 12 to 27 years. The torque ratios were also reported at 30 degrees, 45 degrees, and 60 degrees and it was found that the ratios decreased as the joint angle increased and again was consistent across the four age groups. It was also found that the hamstrings to quadriceps peak torque ratio did not increase (hamstrings becoming stronger relative to quadriceps) as velocity of movement increased as has been reported in other studies. It was hypothesized that the large shear forces that are generated about the knee in gymnastics (extrinsically from backward landing and intrinsically from the quadriceps eccentrically contracting), combined with the relatively weak hamstrings, could be one cause for the increasing incidence of ACL injuries in that sport. The results of this study indicate that it would be prudent for clinicians involved with gymnasts to test for knee strength imbalance and to prescribe exercises to correct it when necessary.

The incidence of meniscal tears associated with acute anterior cruciate ligament disruption secondary to snow skiing accidents

In the acutely traumatized knee, meniscal tears are commonly encountered with an anterior cruciate ligament (ACL) injury. Because of the high incidence of ACL injuries related to snow skiing, a retrospective study was conducted to determine the incidence and location of concomitant meniscal injuries in a series of 328 acute ACL tears resulting from snow-skiing accidents. Seventy-five (23%) of the ACL injuries had coexistent meniscal injuries--43 (13%) lateral and 32 (10%) medial menisci. Thirty-two (43%) of the 75 meniscal tears were peripheral detachments from the capsule (red-red tears), which often heal without surgical intervention. Findings from this study indicate that the incidence of meniscal damage in acute knee injuries secondary to snow skiing accidents is substantially lower than in knee injuries sustained during other sports activities, which range from 53% to 65% in previous studies.

Consideration of the Anterior Cruciate Ligament Injury in Skiing

The anterior cruciate ligament (ACL) injury of the knee is a common ski injury. At a typical ski area clinic in Wyoming, an average of one per day is diagnosed over the 120-day ski season. Other ski clinics report a similar incidence of ACL injuries. In view of the 570 registered ski slopes in the United States, the ACL injuries occur at epidemic proportions. Under consideration are causal factors involved in the typical skier's ACL injury, such as recent evolutions in skiing techniques, boot styles, the skier's environment, and the anatomic considerations relating to body mechanics that place the ACL in a position of compromise in the intercondylar notch. Clear identification of the mechanism of ski injury of the ACL is difficult. As the significant causative factors become identified, and with the stimulation of further interest and research, there is some promise for prevention in the future.