your son is lucky , he had what is called
myelomeningocele which is fluid filled sac in the back , and
hydrocephalus which is the accusation of the fluid inside brain ventricles. most of these children can't walk , or have control on bladder or
rectum because of the damaged and incomplete formation of the nervous system .
the fact that your son can walk is amazing ,
physiotherapy which you did help a lot in that
if we need the child to stand by his own , physiotherapy to the back muscles is very helpful , when that happens , he can balance well .
any small improvement in his walk is very great success for you as a mother .
continue with legs physiotherapy , if you notice a spastic joint especially in the ankle joint , concentrate on that one and request a help from a nearby physiotherapist