Hello,
Thanks for your query at DoctorSpring. I have read your query with diligence. It looks from your details that your grandson is limping.
There are various reason for limping which mainly consist of trauma or injury,infection to bone or infection in joints & various swelling or tumors of bone. There may be concurrent oft tissue or muscle problems which may also lead to limping.Limping is also one of feature which appears in various generalized infection or even minor infections like cough & cold. This is due to concurrent viral affection of joints.
Looking at whole details i will advice you to keep him on rest.You should also get him evaluated from a expert pediatrician. A mild analgesic should be given with advice from his doctor.
Hope this all will help you. Please feel free to discuss further.
With best wishes.