Assessment and evaluation of predisposing factors to anterior cruciate ligament injury

Injury to the knee, specifically the anterior cruciate ligament (ACL), constitutes one of the most serious disabling injuries in sports. Women are reportedly at an increased risk. Prevention depends on identifying possible risk factors that may contribute to an athlete's susceptibility to injury. The major objective of this article is to lay the groundwork for standardization of a screening protocol (1) by providing rationale for the use of selected variables that might be good predictors of noncontact ACL injury and (2) by describing appropriate measurement indices to further investigate their predictive power. Standardization of a screening protocol is the first step in developing both a reliable and valid assessment tool with predictive value for injury and outcome strategies to meet the special needs of patients.

MEDLINE was searched from 1980 to 1998 using the terms "anterior cruciate ligament injury," "knee joint stability," "postural malalignments" "structural abnormalities," "static structural measures," "musculoskeletal strength imbalances," "isokinetic testing," and "functional performance tests."

Many different factors, both extrinsic and intrinsic, have been investigated in the search for predictors of noncontact ACL injuries. Based on a literature review, 3 factors in particular have garnered considerable attention from clinicians and researchers: static postural malalignments with special reference to excessive foot pronation, knee recurvatum, and external tibial torsion; lower extremity musculoskeletal strength; and neuromuscular control considerations. However, much of the information known about the predictive value of these variables is inconclusive and conflicting at best, prompting the need for additional investigation.

Screening evaluations are routinely employed as part of clinical work-ups when athletes are healthy and in top form. The data collected have the potential to provide clinicians with important baseline information for maximizing structural and functional outcome strategies when deficiencies in test results are observed in subgroups of athletes matched for age, sex, and training or performance expectations.