Bunions exist along a spectrum. In some feet, the big toe can be moved towards a more neutral position and the joint remains mobile. In others, the deformity is fixed, the toe may be rotated or crossing beneath another toe, and the joint may be stiff or arthritic.
The examiner may gently assess whether the big toe can be realigned and whether the first metatarsophalangeal joint remains comfortable and congruent in the corrected position. The mobility of the first ray, the position of the sesamoids and the behaviour of the lesser toes are also relevant.
Flexibility does not mean the bunion can be permanently corrected with a splint or exercise. Toe spacers and wider footwear may improve comfort for some people, but they generally do not reverse an established adult bony deformity. Nevertheless, a flexible, non-arthritic deformity can respond differently to treatment from a rigid, degenerative one.
Rigidity may arise from long-standing deformity, joint degeneration, soft-tissue contracture, previous surgery or associated lesser-toe problems. A fixed deformity can require a more complex operative plan if symptoms eventually justify surgery.
Neither flexibility nor rigidity alone determines whether treatment is needed. A painless rigid bunion may simply be monitored, while a painful flexible bunion may benefit from footwear changes or, after appropriate assessment, surgical correction. The patient’s symptoms and goals remain central.