- There are 4 types of pes cavus: cavo-varus (commonest), Calcaneo-cavus, Calcaneus and Plantaris.
- Rang’s tripod theory depicted the foot as a balanced tripod (the calcaneum, the first and the fifth rays)
- Muscle imbalance (or other causes) causes one or more of tripod limbs to change position.
- To resume balance, our body forces the other limbs to change and touches the floor. This usually creates a high arch foot
- For example, if the first ray is plantar-flexed, the three points can only rest on the ground if the hindfoot tips into varus causing cavo-varus foot
- Same would happen if muscle imbalance led to a varus heel.
Types of pes cavus: cavo-varus (commonest), Calcaneo-cavus, Calcaneus and Plantaris. These can overlap.
To depict various types of pes cavus: Rang simulate foot to a tripod.