M21: Other acquired deformities of limbs
M21.4: Flat foot [pes planus] (acquired)
The sole of the foot normally has a slight upwards arch from front to back. The sole of the foot is arched, particularly on the inside of the foot. The arch is important so that the foot can cushion the body’s weight when walking and standing. Connective tissue and muscles stabilize the arch in the foot.
With a flat foot, this arch is absent. The entire sole of the foot then touches the floor when standing. The sole of the foot may even arch downwards slightly.
A flat foot can develop due to overloading or incorrect loading of the foot. It may also be that connective tissue and muscles in the foot are too weak, so that the arch flattens out. A flat foot can also occur after injuries, inflammations and bone disorders.
Patient Disclaimer
The information provided on this page is for general educational purposes only. It is not intended for self-diagnosis and does not replace professional medical advice. Always consult your doctor or a qualified healthcare provider with any questions or concerns about your health.
If you see an ICD diagnosis code (e.g., on a medical report), be aware that doctors may also include additional indicators to express diagnostic certainty. Only a healthcare professional can interpret these codes accurately in the context of your individual case.
For a complete understanding of your condition and what the diagnosis means for you, please speak directly with your doctor.