The hallux valgus angle (HAV) or hallux abductus angle is the angle formed between the
longitudinal axis of the first proximal phalanx and the longitudinal axis of the first
metatarsus.
A. In hallux varus or adductus the
HAV is less then 5º. 
B. In
normal subjects HAV is 5º to 15º . Hallux abducto valgus is mild when HAV is 16º
to 25º,
C. moderate when HAV is 26º
to 35º, and severe 
(D) when HAV
is greater than 35º.
