online Video 1: An

overview of the role of the ligaments of the knee (credit to YouTube user BertrinZarinsMD) http://bit.ly/cDNTsH

tibia, in which case an x-ray may be useful.

– Giving way tends to be due to sudden pain in the knee with the muscle activity shutting off. Rarely does the patient do more than stumble, then regain their balance. Muscle strengthening is often effective. Patello-femoral problems (including subluxation laterally (video 12) and restoration of patella position may be the cause - see below for more details). There may be no acute injury.

working both concentrically as well as eccentrically, in order to fully understand their actions. A good history and examination will often help locate the source of the knee ‘problem’

+ 8 HISTORY

Pain from the knee is mostly felt around the knee. Some structures have specific pain areas, some don’t. Injury or pain from the more superficial structures tends to be located by tenderness of those structures. Deeper structures such as the cruciates tend to be less location-specific unless stressed during movement or diagnostic tests. Knee pain can be referred from and to the hip joint as both joints share the same innervations (L2,3,4). Myofascial pain from the

quadriceps tends to be local, as does hamstring pain (1).

It is important to establish the method of injury in order to ensure

the movement of the knee. The two major muscle groups (quadriceps and hamstrings) oppose each other, before reversing roles in the gait cycle. The recurring theme of stabilising muscles having to maintain effective joint movement/articulation before the prime movers can work efficiently, also applies to the knee. Dysarticulation leads to pain and reduction of movement, which compounds the initial problem. In the knee the vastus medialis (VM) and vastus medialis obliquis (VMO), play key roles in stabilising the patella, to allow the quadriceps to work effectively. Weakness of VM and VMO can be a cause of patella-femoral maltracking which is in turn a cause of anterior knee pain (AKP).

KEY POINT: It’s really important to familiarise yourself with the muscles around the knee, along with their attachments

a correct diagnosis. The following questions are important: n What activity was being undertaken at the time of injury? n What was the force exerted on the knee (i.e. did another player fall on the subject)? n What happened to the knee? – Was it twisted - if so the MCL, cruciates and menisci are most commonly affected – Was it hyper-extended/flexed - often a muscle injury or occasionally ACL

n Did it swell and when? A watershed of four hours divides cruciate injury which swells within 4 hours, from other ligament or menisci injury which tend to swell 4 or more hours later. n Did the person have to stop playing immediately? This usually indicates a cruciate injury or occasionally a fracture of the tibia. n Did the person hear anything i.e. a pop or crack? This is common in cruciate injury. n Was there any pain and when? Similar causation as swelling/timing covered above. n Did they give the knee any treatment? Hopefully R.I.C.E. - often nothing! n Are they experiencing any locking and giving way?

– Locking is important – if it’s true. True locking comes on suddenly and goes off quickly, often with the knee positioned/moved in the same way. It is painful! The patient will often have self-learnt a movement/ trick to unlock it. From the author’s personal observation the pain is like cramp - you want to stop it quickly. It is often due to a loose body in the knee ie. meniscal fragments or tears, or possible bone fragments – think osteochondritis dissecans of the

Overuse injury usually involves increased activity e.g. more frequent/ longer or more intense runs or resistance exercises. The contractile components of the knee, usually the quadriceps mechanism, are affected by overuse injury e.g. the quadriceps muscle, tendon, patella, patellar ligament and all their attachments.

EXAMINATION As with the shoulder, my personal examination technique involves three steps, look, move and feel. The order is more physio-like to encourage full range of movement (FROM) possible before one causes pain by palpation. Firstly the patient undresses uncovering the whole of the leg.

Look n As the knee plays an important role in standing, observe the knees weight bearing and if possible walking. n Check the size of the quads visually for any wasting especially VMO. Walking may reveal a painful (antalgic) gait or lack of full extension as in arthritis. n Lying the patient down, look for effusion; a small effusion may need demonstrating, a large effusion is obvious around the inferior aspects of the patella, the lateral aspects of the knee or even in the supra-patella pouch (above the patella) which communicates with the knee joint. A method to demonstrate a small effusion is to firmly stroke the supra- patella pouch towards the knee, then stroke over the medial aspect of the knee, a flick of swelling on the lateral aspect indicates a small effusion.

Move n Firstly I examine hyperextension (video 2). A normal knee will hyperextend past 180o

by 5-10o . sportEX medicine 2010;45(Jul):7-12