We thrive on participating in and completing many different activities which to a large extent depend on the condition of our body joints, from the large joints of locomotion (hips, knees) to the small joints such as the temporo-mandibular for speaking and eating. Our well-designed and durable joints do a very good job of allowing us to get about and involve ourselves in activity. Damage to our joints can be the result of disease, illness or trauma and this can restrict our mobility and reduce our functional capacity. Joint examination is a core ability of physiotherapists, consisting of a logical assessment, testing to find an abnormality and targeting of the treatment plan to these problems.

Joints, the junctions between two bones, can have weight carrying, force transmission or movement properties depending on their design and position in the body. An example of a movement joint is the shoulder with its great range, the acromio-clavicular joint is a force transmission joint allowing arm function and the back and hips are weight bearing joints with some movement function. The most obvious of our joints are all synovial joints, a particular and very important joint type. The bone ends are coated with articular cartilage which reduces friction, the joint fluid is secreted by the synovial joint lining membrane and the joint capsule, formed by the ligaments, holds the joint protected against mechanical forces.

Observing the patient as they walk into the examination room and sit down can give the physiotherapist valuable information about the state of their joint. Slow and guarded movement is common, along with splinting of the joint and carrying it in a close and protected position to minimise joint stresses. Once the physio has taken a history they will check out the joint visually, looking for swelling, effusion, warmth or a joint deformity. If there is no obvious problem in a cool, settled joint the physiotherapist will need to stress the joint more thoroughly to find the restriction. However, a swollen, inflamed joint should be treated acutely as soon as possible.

The physiotherapist will initially observe the patient as they make their way into the exam room and sit down. They might limp, splint the joint in some way, have very guarded movement to reduce joint stresses or hold the joint in a protective position to minimise further injury. A history will be taken by the physio initially then they will move on to examine the joint visually, looking for normal alignment, any warmth, effusion or tissue swelling. There may be a fault in a cool joint with no swelling but the physio will have to test it more thoroughly to discover the fault. If the joint is inflamed, hot and swollen then acute treatment should be instituted.

Active joint range of motion is then assessed and this is the joint movement the patient can do for themselves. Depending on the joint, this is expressed in degrees or as a proportion of the tested normal range on the other side, with limitation of range noted and the reason. Passive range is then tested and the physiotherapist moves the joint for the patient to see if any more movement is possible within the limits of discomfort. If the active range is poor and the passive range full, i.e. the joint can move where it should, then weakness or pain may be the limiting factors. If the passive and active ranges are both restricted then joint stiffness may be the problem.

The physiotherapist will assess the active range of the joint movement which is what the patient can manage independently, noting the ranges as a proportion of normal and why the joint could not achieve full range, e.g. pain or muscle weakness. The physio will then move the patients joint passively without the patients effort to see if the joint ranges are different. If the physio can move the joint through its full normal range but the patient cannot do this, then either pain or muscle weakness is the likely cause. If neither the physio nor the patient can get the joint to full range, pain or joint stiffness may be the problem.

The last part of the examination is to test the joint in functional activities or positions, especially if there is little to find on the more detailed examination. The physiotherapist can see how the patient is willing to use the joint and this may reveal difficulties with joint function which until then have not been clear.