The knee is particularly vulnerable to injury and accidents due to its position in the leg, and injuries lead to pain, joint instability and loss of normal leg function. The initial part of the examination looks at the injury cause and the forces involved, how fast the knee effusion came up, the presence of joint instability on walking and whether the patient is unable to take normal body weight on the knee.

The pain levels after injury indicate important things about the state of the joint. Knee fractures are fairly clear as there are high levels of pain and there is therefore little chance of missing this injury. The type of knee injury gives pain in specific areas which indicate which structures have been damaged. The physio will test these structures later in the examination.

The Knee Examination

The physiotherapist will look at the knee and check for effusion by observation or doing the patellar tap test. The knee can swell greatly and be very tight, needing aspiration by a needle. How well the knee can move when not weight bearing is assessed by the physio. Knee extension is the movement of straightening the knee out and flexion is bending the knee. The knee does have a certain degree of rotation but that is rarely checked in the initial period.

The reaction to examination testing indicates how the treatment plan should proceed. The pain level, ease of joint movement and reaction to tests are included in this assessment. The patient moves the joint actively with the physiotherapist adding passive movement to test the joint further. The power of the main antigravity muscles, the hamstrings and quadriceps, are tested by manually resisting the knee movements or asking the patient to perform weight bearing movements.

Manual testing of the knee ligaments by the physiotherapist tells him or her about these important stability structures. The physio levers the knee inwards and outwards to test the medial ligament and the lateral ligament (the collateral ligaments) and pulls the shin bone back and forward to test the anterior cruciate ligament and the posterior cruciate ligament. Manual palpation around the joint and adjacent structures can help indicate which structure has been injured.

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.

Exercises to increase the strength and movement are instigated once the pain and effusion have begun to settle, working on the major weight supporting muscles of the thigh, the quadriceps and the hamstrings. The knee extensors (quadriceps) push us up from a chair, control the knee in running and walking and push us steps. Exercise progression by the physiotherapist involves non-weight bearing exercises initially, followed by rehab exercises in the gym and finally sport-focused activities.

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.