A physical exam helps your doctor distinguish mechanical problems, such as a shoulder dislocation, from conditions that affect soft tissue, such as tendonitis or bursitis. An exam also helps distinguish mechanical problems from joint diseases, such as osteoarthritis.
The main goals of a physical exam of a joint are to:
- look for warmth and tenderness over a joint
- determine if there is any swelling over a joint
- test for pain when the joint is moved or lightly touched
- check your ability to move the joint
In some cases, your doctor may want to take X-rays or perform other tests.
Why does the doctor look for warmth, swelling and tenderness?
Joints affected by arthritis often look swollen and feel warm and tender when the skin over the affected area is lightly touched. Although these factors can be present in other conditions, examining them closely provides your doctor with important clues.
For example, fluid that builds up within a joint space can cause swelling that becomes firm when the joint is bent. This often occurs with rheumatoid arthritis, other inflammatory joint diseases, and sometimes even in osteoarthritis in the knee. In these cases, the doctor will often remove some of the fluid through a thin needle, using a process called aspiration. This allows the doctor to see if the fluid shows signs of inflammation, such as white blood cells, crystals, or signs of infection.
On the other hand, when a joint appears swollen in osteoarthritis, it is usually due to bony growths or the widening of bones. The doctor can feel these by lightly squeezing the joint.
Warm skin over the joint suggests that inflammation is present. Very warm, red skin points to an infection. It also could be a sign of gout or rheumatoid arthritis.
Why does the doctor move the painful joint?
Joint diseases such as arthritis limit the ability of a joint to move fully. With osteoarthritis, joint motion can be limited by bony growths or from severe loss of cartilage. For example, pieces of cartilage in the joint space can cause a joint to lock. The doctor will also move the joint to see if it produces a grating sound, called crepitus, which indicates a loss of cartilage that causes two bones to rub against each another.
Your doctor may ask you to walk and turn around, stand up straight, and touch your toes to determine if you have any limit in joint function. You may also be asked to place your hands behind your head, by your side, and in front to check for your ability to move joints and extend them fully as well as for swelling and deformity.
To test for osteoarthritis of the hand, you may be asked to squeeze your doctor's finger, hold onto a piece of paper while he or she tries to pull it away, or pick up a small coin or object. The doctor may also place pressure on a possibly affected area to see if the joint is stable or not. To learn more about the characteristic symptoms of osteoarthritis in a particular joint, see When Do Symptoms Occur?