this is what is explained:
"Genu varum (bowleg) is presnt when a space of more than 2.5 cm is measured between the knees as the medial malleoli are held together."
"Genu valgum means that more than 2.5 cm remains between the medial malleoli when the knees are held together."
(genu valgum is knockknees - so where is 2.5 cm between the medial melleoli? I can see space below the knees)