Injuring the knee is one of the most common general and sporting injuries and can give long-term problems with pain, stability and functional activities. Physios begin with the subjective examination, asking about the cause of the injury, the amount of force involved, whether the knee swelled up quickly or the knee was unstable afterwards and the person found it difficult to weight bear.

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.

Objective Examination of the Knee

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 physiotherapist decides where to start treatment by their findings - how much the patient can easily move the knee, how much pain they have and how the knee behaves on testing. Active movement the patient can do themselves and the physio may gently push the joint further to test weakness or guarding. The physio will test the strength of the quadriceps and hamstrings which straighten and bend the knee respectively, seeing how much the pain or weakness affects the knee function.

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 plan

An acutely painful knee is treated using the PRICE technique, starting with protection of the joint if necessary by using a brace to stabilise it. Crutches or sticks can be used to reduce weight bearing on the knee and allow a good walking pattern. Ice treatment, or cryotherapy, is a first line treatment for an acute knee, reducing pain and the swelling which permits increased movement and progression of treatment. A neoprene knee sleeve may be worn to squeeze the swelling and increase stability.

A reduction in swelling and pain allows the physiotherapist to give exercises to improve the knee’s ranges of movement and strength. The largest and most powerful muscles are the quadriceps and the hamstrings. The quadriceps allows knee power for getting up from sitting, going up and down stairs and walking, keeping the knee stable. After the knee copes with exercise on the plinth the physio will move to exercises in weight-bearing and in more active activities.

Proprioception is the body’s natural joint position sense, with the brain sensing the moment to moment position changes of the knee and co-coordinating the muscle actions needed keep the joint within safe bounds. Physio treatment is balance practice, starting with standing on one leg, then balancing and catching balls on a wobble board and finishing with running, changing direction suddenly, hopping and jumping. Once the swelling has settled and the strength and co-ordination ability restored the knee is ready to rejoin normal and sporting activities.