Flexibility tests are used to measure the range of motion in a joint and are often part of the physical examination. They may be used to help determine whether you have a muscle imbalance or arthritis in a joint. They may also be used to help determine the progression of a condition such as shoulder impingement or a sprain. There are several different kinds of flexibility tests, geared to specific joints and muscles. Your doctor may ask you to reach or bend or to move the affected extremity in a certain way. No preparation is required, and normally these tests are not painful.