The limp in childhood is a problem faced often. It causes anxiety because the reason for the limp can be obscure and indeed there may not even be an identifiable cause.
Stiff Leg Limp

A painless stiff joint can occasionally be the cause of a limp in childhood.
Limp associated with talipeqs equino varus or vertical talus.
Post - traumatic or post Infective joint stiffness.

More Information on Limping