The foot has three arches; the medial longitudinal arch, the lateral arch and the transverse arch.
The arches are maintained by the alignment of the foot bones, the tone of the muscles and the strength of the ligaments.
The long arch
The long arch has a plantar fascia that runs from the rearfoot to the forefoot. It is an emergency feature that springs into action if you jump. It helps to keep the arch up in these high force scenarios. If the plantar fascia is inflamed it means it is being overworked. The arch must be lifted up and supported to decrease the tensile stress of the plantar fascia. If the arch is not supported the heel can get very painful as the plantar fascia plays tug-of-war with the attachment into the forefoot.
If the transverse arch collapses the foot can become wider and the bones can eventually protrude. When this happens it is called a bunion and bunionette. The dropped metatarsal bones also push into the muscles under the ball of the foot and cause a burning sensation. An orthotic is prescribed to lift the forefoot metatarsal bones back up again.
The outside of your foot has a little invisible arch. This is where the long bones called the metatarsals meet the cube shaped bones of the feet. At this junction there is an important network of bindings. If this structure fatigues and collapses it can cause a bunionette and pain along the outside of the foot and leg.