Doctors know the right questions to ask to get to the bottom of a problem. Snapping, clicking, popping joints have a couple of possible causes. In the case of the hip, it could be the tendon popping back and forth over the bone. That would be outside the joint. If the joint cartilage is torn, a locking or catching sensation in the groin occurs.
The doctor will look at your range of motion. The loss of motion in certain positions or directions can help narrow down the problem. Posture and gait pattern will be assessed. Muscle strength can be tested. The legs can be measured for a leg length difference.
Other special tests can be done to look for pinching of the soft tissue structures, loose bodies in the joint, and labral tears. When needed imaging studies can be done. X-rays show changes in the bone and joint. CT scans or MRIs help define the size, shape, and location of problems.
Truthfully, even with all the right questions and tests, it isn’t always possible to pinpoint the exact problem. Sometimes the doctor takes a conservative route to treatment and waits to see if the patient gets better. The exact cause of the problem isn’t always known.