As children return to school and sports, the issue of foot problems come to the forefront. We often get questions regarding foot pain and foot shape and how this affects walking and running.
As https://www.healthychildren.org/English/health-issues/conditions/treatments/Pages/Orthotics.aspx describes, when walking and running, the foot undergoes pronation and supination. Pronation occurs when the foot lands on the ground. the arch flattens, the heel flares out and the shin bone rotates inwardly. This allows the foot to absorb shock and adapt to the surface.
A flat foot pronates excessively. Excessive pronation results in the arch collapsing with weight bearing. Due to the instability of a pronated flat foot, the leg muscles have to work extra hard to stabilize the foot during walking and running. This can cause shin splints and stress fractures. A flat foot also is associated with increased tibial rotation and can lead to knee problems. an orthotic that supports the arch can help treat these conditions.
Supination happens before pushing off with walking or runing. Supination raises the arch, inverts the hee., and makes the foot more rigid to allow for push off. A foot with a high arch is rigid and supinates. This foot type has stability and support but lacks flexibility for shock absorbtion. This rigidity can lead to stress fractures or overuse injuries. A rigid orthotic for this foot type is not recommended because it may increase the risk of injury, but an shoe insert that provides cushion may be helpful.