Internal tibial torsion is the major component of which physiologic bowleg condition?

• A. Genu varum
• B. Genu recurvatum
• C. Tibial bowing
• D. Genu valgum

Answer: (D)

In children, the alignment of the legs during growth is influenced not only by how the bones bend but also by how the tibia is rotated. When the tibia is rotated internally, the distal tibia points more toward the midline relative to the femur, which shifts the knee into a knocked-knee pattern. This rotational component—internal tibial torsion—tends to be the dominant factor in physiologic genu valgum (the “knock-knee” pattern) seen in early childhood, and it often improves as the child grows.

So the knee having a valgus alignment in this physiologic context is driven mainly by the tibia’s internal rotation, rather than by a significant angular bow at the knee itself. Other options describe different structural issues—like tibial bowing being the angular bow of the tibia, or recurvatum being hyperextension at the knee, which are less central to the common physiologic genu valgum pattern.