Well at this age....popping of joints is not very common,,,there could be many reasons for it...which joints in the body are popping/loose/unstable,,can you be a little bit more specific.
It can be related to lax musculature around the joints or could be dearangemet in the the joint it self
Next Steps
you would need blood test to know the status and
calcium n vit D and also xrayz for the joints involved
Health Tips
If problem could be because of lack of certain nutrient in body then appropriate supplimentation could be started or if its bcos of loose n weak musculature then vigrous Physiotherapy protocol is needed.
Regards & take care.