The relationship between clinical measurements of lower extremity posture and tibial translation.

Objective: The purpose of this investigation was to determine if postures of the lower extremity were related to the amount of anterior tibial translation.

Design: Regression model of lower extremity postural measures used to predict the amount of tibial translation for a sample of convenience.

Background: Retrospective studies have indicated a link between certain lower extremity postures and prediction of anterior cruciate ligament injury status. What is not clear is whether these lower extremity postures cause, or occur as a result of anterior cruciate ligament injury.

Methods: Genu recurvatum, the thigh-foot angle, and navicular drop measures were obtained from the right leg of 43 uninjured college-aged subjects. Tibial translation was determined using a KT-1000 arthrometer. Gender related differences were determined with independent t-tests. Step-wise regression was performed to assess the relationship between postural measures and subject gender, and tibial translation.

Results: Very good to excellent inter- and intra-rater reliability was found for the postural measures. There was greater tibial translation (P=0.01) in females. The final regression model indicated a moderate relationship between sex of the subject, navicular drop and tibial translation (r=0.551). Genu recurvatum and thigh-foot angle were not significant predictors of tibial translation. CONCLUSIONS; We concluded that foot pronation has a greater impact on the amount of tibial translation than genu recurvatum and torsion of the lower leg in anterior cruciate intact subjects.

Relevance: Static clinical measures of lower extremity posture are commonly taken as predictors of outcome (both performance and injury). There may be little association between these static measures and dynamic performance.