Bunions may be caused by foot mechanics that result in
too much pressure on the joint at the base of the big toe (metatarsophalangeal joint ). An abnormal
foot motion called
excessive pronation , having certain foot shapes such as
flatfoot, and wearing shoes that squeeze the toes
together or shift weight to the toes (such as high-heeled shoes) may all
contribute to the pressure. Over time, the constant pressure forces the big toe
out of alignment, gradually bending it toward the other toes (displacement ).
bunionette , or tailor's bunion, is one that develops
at the base of the little toe. When the long bone that connects to the toe
(metatarsal ) bends away from the foot, the little toe
bends inward and the joint swells or enlarges.
Other factors that
can lead to a bunion include:
ligaments in the foot.
- Previous injury to
- Hammer toe or removal (amputation) of
the second toe. When the joint of the second toe rises, as in hammer toe, or
the second toe is missing, it becomes easier for the big toe to drift toward
the other toes.
- Abnormal development of the foot.