
Illustration showing foot before and after orthotic correction.
Pes planus is the same as flat foot. Page updated April 2024 by Dr Sheila Strover (Clinical Editor)

Illustration showing foot before and after orthotic correction.
With flat feet (pes planus or foot pronation), the lower leg is forced into internal rotation, and the stress is relayed to the knee and the kneecap.
Peer-reviewed papersQuote from peer-reviewed paper:
Citation: Gross KD, Felson DT, Niu J, Hunter DJ, Guermazi A, Roemer FW, Dufour AB, Gensure RH, Hannan MT. Association of flat feet with knee pain and cartilage damage in older adults. Arthritis Care Res (Hoboken). 2011 Jul;63(7):937-44. doi: 10.1002/acr.20431. PMID: 21717597; PMCID: PMC3087845.
Quote from peer-reviewed paper:
Citation: Açak M. The effects of individually designed insoles on pes planus treatment. Sci Rep. 2020 Nov 12;10(1):19715. doi: 10.1038/s41598-020-76767-y. PMID: 33184442; PMCID: PMC7665030.
Quote from peer-reviewed paper:
Citation: Gross KD, Felson DT, Niu J, Hunter DJ, Guermazi A, Roemer FW, Dufour AB, Gensure RH, Hannan MT. Association of flat feet with knee pain and cartilage damage in older adults. Arthritis Care Res (Hoboken). 2011 Jul;63(7):937-44. doi: 10.1002/acr.20431. PMID: 21717597; PMCID: PMC3087845.