Background: An increased femoral anteversion may be a risk factor for patellofemoral pain and is measured by Craig's Test clinically using a goniometer. However, its validity has not been examined. The purpose of the present study was to examine the validity of Craig's Test, with those measured using computed tomography (CT), and to investigate the relationship between femoral anteversion and knee external rotation.
Methods: Twenty-six college students (13 men and 13 women) were measured their femoral anteversion values by Craig's Test (FACraig) and CT (FACT) and knee external rotation values by CT (KERCT). Multiple regression analysis to predict FACraig using FACT and sex was conducted. Mixed design (Measurements × sex) ANOVA examined the difference in FACraig and FACT. Pearson's correlation coefficients examined the relationships between FACT and KERCT for each sex.
Results: FACT (B=0.41, P=0.014) and sex (B=-5.22, P=0.075) together explained 23.4% of the variance in FACraig (F=3.52, P=0.046). FACraig was significantly smaller than FACT in females while no significant difference was found in males. Greater FACT was significantly related with greater KERCT (r=0.47, P=0.02) in females only.
Conclusions: Craig's Test does not provide highly valid values to reflect the true femoral anteversion despite its clinical significance. Greater femoral anteversion may be associated with increased static knee external rotation, possibly resulting in increased quadriceps-angle and thus patellofemoral pain risk.