Why are people with flat feet not allowed to join the army? Or is it just a myth?

Saul Cohen, London UK

• At least in the US and Canadian armies, the answer depends upon the definition of "flat feet". Most feet that could be labeled "flat" are not an impediment but a small proportion (3% of all examined in one study) were so malformed as to disqualify. It may be that discharge for flat feet that is so commonly claimed is actually for other, less socially acceptable reasons.

  David Dreaming Bear, Horsethief Canyon, California USA

• Those with flat feet are not suited to marching - they can sustain spinal damage. The government may not care if one is killed, but cannot take the chance of anyone's seeking a disability pension.

  Elizabeth M, New York City US

• Marching requires a heel to toe foot movement that cannot easily be achieved by someone sporting feet akin to Donald Duck!

  Darius Hurley, Chicago USA