When might there be a problem ?
- If your foot changes to this shape having started off with an arch.
- If you develop pain where there was none before.
- If your foot becomes fixed in this position, wheras previously it was flexible .
- If the flat foot is on one side only (unilateral).
A right sided flat foot, the left side normal.
Are there any other variants of foot shape?
The main other pathological foot shape is the cavo-varus or equino-cavo-varus foot.
Cavus means a high arch. Varus that the heel moves towards the midline of the body and equinus that the foot angles downwards (like a ballerina "en pointe")
The cavo-varus foot
What makes the arch?
The inner arch of the foot is formed and maintained by:
- Bones /joints: The alignment of the bones (calcaneum ,talus ,cuboid,navicular,cuneiforms and metatarsals) and the joints which they make with each other)
- Muscle/tendon : The pull of the Tibialis posterior(Tib post) tendon and its balancing muscles(antagonists) the peroneals.
- Ligament :tight and unyielding ligaments sitting deep on the inner border of the foot (The spring ligament in particular) and the sole of the foot (the plantar ligaments).
Interactive Foot and Ankle 2 (C) 2000 Primal Pictures Ltd