Do custom in-shoe orthotics work well for acquired flat feet (valgus)?

They can be...: See a podiatrist and your visit should include a foot examination, possibly xrays and gait (walking) evaluation. Orthotics are prescription devices to help accommodate and help the foot function. As a means to treat conservatively (avoid surgery), many times, orthotics are used to hold the foot in good anatomic position and avoid abnormal mechanics which can lead to further problems.

Usually not: Orthotics are usually not well tolerated, especially with flatfeet. If you must try them try otc orthotics like superfeet or powersteps first. It is a lot cheeper to find out if you are okay with them for $30. Calf stretching is what must be done for flatfeet. One stretch.Com.

Yes: An acquired flat foot may represent an injury to the posterior tibialis tendon due to repetitive overload. An orthotic may help establish the normal mid foot alignment. Start with an accomodative orthotic over the counter such as a "first step orthotic".

Orthotics: Yes they do . Stretching is not the answer to everything , as some docs would have you believe. See your podiatrist for an exam and real orthotics