Arch heights vary. Someone who has a low arch profile is not necessarily flat footed and does not incur more pain or injuries compared to a person with a higher arch. A true flat foot usually presents with muscular weakness, foot and lower limb fatigue and a lack of stability.
Orthoses (insoles) can reduce the forces to the flat foot and place the foot into an alignment more able to cope with the loading forces.
Specific strengthening exercises are used to strengthen muscle weakness in the flat feet.