Fig. 6.

Illustrations showing the variation in tibial slope at low hip-flexion angles (safe position) and high hip-flexion angles (provocative position) relative to the gravitational vector. The average hip angles were obtained from the study by Sheehan et al.¹⁶. The average ankle and knee angles were obtained from the study by Boden et al.¹⁷. It should be noted that the inherent slope of the tibial plateau for both images was assumed to be 6°. (Reprinted, with modification, from: Boden BP, Breit I, Sheehan FT. Tibiofemoral alignment: contributing factors to noncontact anterior cruciate ligament injury. J Bone Joint Surg Am. 2009 Oct;91[10]:2381-9.)