ACL Prevention

Anterior cruciate ligament, or ACL, tears are one of the most common injuries affecting athletes in the United States. Estimates of between 100,000-200,000 of the injuries occur every year, often from non-contact injuries while engaging in cutting and twisting movements. Females have been estimated to suffer these type injuries at rates between four and eight times their male counterparts. As the number of female athletes participating in sporting competition has exploded in recent years, this disparity has created a near epidemic of ACL injuries in the female athlete.

Numerous reasons for this disparity have been expounded. They range from anatomical differences between the sexes, hormonal variations, environmental concerns like playing surfaces and shoes, and likely most important biomechanical factors such as muscular strength and endurance, movement patterns, position, and patterns of neuromuscular control. It is this factor which has seen a significant amount of research and promise in reducing the rates of ACL injury in these athletes. The Santa Monica Orthopaedic and Sports Medicine Research Foundation, and their partners at the University of Southern California, under the direction of Dr. Bert Mandelbaum and Dr. Christopher Powers, have been pioneers in this field. At the completion of my orthopaedic training I spent a year of specialty training with this group, and was exposed to a range of the newest treatments in sports medicine, including ACL prevention strategies

Their research identified several critical factors where female athletes differed from their male counterparts and were felt to contribute to their increased risk of ACL injury. First, women were found to run more erect, with decreased bending at the hips and knees. This is critical because the forces seen by the ACL are significantly less as the knee goes into more flexion, or bending. Second, diminished recruitment and strength of the hamstrings and hip musculature was seen, again placing the limb into a position known to increase the forces the ACL is subjected to. Third, landing patterns in females demonstrated a propensity for absorbing impact through hip and knee rotation instead of bending at the hips and knees, again placing the ACL at higher risk for rupture. In reviewing this and results of other interventions previously espoused to reduce ACL injury, this group created the PEP, or Prevent injury and Enhance Performance, Program. Five key areas are stressed in this program: avoidance of limb positions that place the ACL at risk, improving flexibility, improving strength of deficient muscles, plyometrics to improve landing techniques, and agilities. Athletes participating in this training program, which is done three times a week for a period of 15-20 minutes during their normal warm up period, demonstrated improvements in multiple areas known to affect ACL injury rates including landing patterns and muscle strength. Most importantly, in the first year of enrollment in the PEP program, they demonstrated an 88% reduction in anterior cruciate ligament injury for their athletes. The same authors demonstrated a 100% reduction in non-contact ACL injuries, the most common type, when they enrolled Division I female soccer players in the program.

With this fascinating data in mind, we at Loeb Orthopaedic Group and Frazier Rehabilitation have applied the PEP program to not just ACL prevention, but ACL rehabilitation. After surgery these same principles are applied to get athletes back in the game, to not just participate, but to excel.