Bunions are
most widely considered to be due to an imbalance in the forces that
is exerted across the joint during walking. The resulting abnormal
motion and pressure over the joint, over many years (combined with
poor fitting footwear) leads to instability in the joint causing
hallux valgus and bunions. Bunions are really only a symptom of
faulty foot mechanics and are usually caused by a combination of
the way we walk, the foot we inherit and inappropriate footwear
use.
Bunions are
not inherited, but do tend to run in families. What is inherited
is the poor or faulty foot type, that mechanically can lead to the
instability around the joint that will eventually lead to bunions
- how soon, how quickly and how bad they are or become is assumed
to be very dependant on the footwear.
A number of
other factors are known to play a role in the cause of bunions and
hallux valgus. Bunions can follow foot injuries and develop in those
with neuromuscular problems. Those with flat
feet or pronated feet
appear to be more prone to the instability about the joint and have
a higher incidence of bunions. Some activities (eg ballet dancing)
puts added pressure on the joint and may increase the chance of
bunions developing.