Painful knee analysis by physiotherapists
November 21st, 2008
The amount of pain a patient suffers indicates the severity of the injury involved and the particular location of the pain can point to which anatomical structures have been injured. As the knee will be very difficult to walk on in the presence of a fracture these injuries are rarely missed in diagnosis. During the examination the physiotherapist will test the knee structures to look for the cause of the injury.
The Objective Examination
Knee effusion or joint swelling is an indication of the degree of inflammation present in the knee and the physio will check the amount of swelling manually. If the swelling is severe it can be drained using needle aspiration to relieve the pressure which can interfere with normal muscle recruitment and function. The physio records the movements of the knee on the plinth non weight bearing, assessing straightening and bending of the knee (extension and flexion) and the small degrees of rotation.
The patient is asked to move the knee and the physio judges how keen they are to move in the presence of pain, indicating where rehab needs to be started. Once the active range (what the patient does for themselves) is known the physiotherapist may try and push the joint a bit further to see if there is a problem or just guarding. Muscle testing of the quadriceps muscle for knee extension and the hamstring muscles for knee flexion inform the physio about the state of the muscles and how much strength the patient can exert without too much pain.
The medial and lateral collateral ligaments of the knee give side to side stability to the joint, and the anterior cruciate ligament and posterior cruciate ligament provide front to back stability. Provided pain is not severe the physiotherapist will test these ligaments manually, pushing the knee into knock-knee and bow-leg for sideways stability and the forward and backward movement of the shin bone to assess cruciate function. The physio will palpate round the joint manually to search for clues to injured structures.
Physiotherapy treatment
Cryotherapy, or cold treatment, is an initial treatment for an acute painful knee and is used to reduce the swelling and pain. If pain is reduced then movement can occur more readily, allowing rehabilitation to progress to the next stage. A compression sleeve useful to compress the effusion as swelling inhibits the function of knee muscles. Of the knee is unstable on weight bearing a brace can be used to stabilise and protect it, with crutches or a stick necessary if the patient cannot weight bear well or achieve a reasonable gait.
Once the swelling and pain are under control the physio will work on the range of motion and move onto the strength of the major muscles. The quadriceps is the most important knee muscle, allowing normal gait and stability in the knee, and so this is the first and main target of muscle strengthening physiotherapy. Weight bearing exercises are started once the knee has settled and progressed to gradually more dynamic exercises.
A normal knee joint involved in activity sends a stream of impulses up to the brain, informing us of the joint position at all times, the degree of muscle activity and movement. This is known as joint position sense (JPS) or proprioception, which is lost to some degree after injury and restoring it to a normal level is vital if the knee is to successfully return to activity. The physio starts with balancing on one leg and progresses to standing on a wobble board and finally works on active, dynamic exercises in preparation for sport.


