At this age plain X-rays are usually enough to rule out serious problems like infection, fracture, or tumor. Occasionally a stress-related injury can cause a fracture in the vertebral bone. This is called spondylolysis.
Other imaging studies may be helpful. Bone scans can be used to show any defects that might not appear clearly on X-rays. MRI or CT scan are sometimes ordered after normal X-rays. It’s not clear which testing is best. Scientists are actively trying to find the best test for this problem.
Most sports medicine physicians will advise caution when playing while having back pain until the problem is clearly identified. Pain-free sports competition is the goal.