hallux valgus

(medicine) A deformity of the great toe, in which the head of the first metatarsal deviates away from the second metatarsal, that is, toward the outside of the foot, and the phalanges are deviated toward the second toe, causing prominence of the metatarsophalangeal joint.

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Permanent lateral (outward) displacement of the great toe in which the sesamoid bones under the head of the first metatarsal are displaced so that they lie between the first and second metatarsal. Normally, the great toe can be angled outwards by 10°, but in hallux valgus the displacement is greater. It is a common disorder in those who wear pointed toes or who exhibit excessive pronation.

Deviation of the tip or main axis of the big toe toward the outer side of the foot.