Bicycle Motocross (BMX) racing has become very popular since it got started in the early 1970s. Soft tissue injuries and bone fractures are not uncommon in either the freestyle or the racing competitions.
Studies show that even inside a cast there is some motion. A small amount of pressure, force, and movement is actually helpful to bone healing, but too much and there can be a delay in healing. Not only that, but the quality of the newly formed bone is less when
there’s too much load through the healing bone.
Most doctors advise patients to limit their activities during the first four to six weeks of healing. This helps prevent tissue damage from high stress and strain. How much your son can do is based on the type of fracture, his general health, and the kind of brace or cast he is in.
Be sure and talk to his doctor about your concerns. Get some guidelines directly from the doctor about BMX activities in particular.