My son is 5 yrs. old. He has sw-cah and has complained (more than I consider normal) of his legs hurting him.  At times he has even stopped playing and rested on the couch because of it.  At first, his pediatrician said it was just "growing pains", but after continued complaints from my son, she tested him for a problem in the bones due to steroid use. It was just an x-ray of his hips and knees.  Everything turned up negative.  It has been a couple of months since his last bout.  I will keep my fingers crossed.  Good luck to you!