This following article is useful for both seasoned and new physios.....
Because pain in the posterior knee is relatively uncommon, its cause is often difficult to surmise. Among several of the known causes of posterior knee pain, and attempts to provide practitioners with a list of potential disorders and tips to consider when conducting a physical exam. The importance of obtaining a good history to elicit information leading to appropriate diagnosis can not be overemphasized. Of particular note is the determination of the precise location of the patient's discomfort within the posterior knee.
Clinicians should try to isolate the location of pain as being in the posteriolateral aspect, medial aspect or center of the posterior knee. Also critical is the knowledge of whether the pain truly arises from the posterior knee, or whether it is being referred from a more distant source.
Among the major disorders that elicit posterior knee pain:
*injuries to support structures and tumors, such as Baker's cyst, soft-tissue tumors, bone tumors, and meniscal tears;
*tendon strains/injuries, such as those to the hamstring or popliteus tendon, or calcification of the gastrocnemius tendon;
*ligament injuries, such as injuries to the posterolateral corner;
*vascular and nerve injuries, such as popliteal artery entrapment syndrome, common peroneal nerve entrapment and tibial nerve entrapment;
*iatrogenic injuries, such as postsurgical arthrofibrosis and placement of bioabsorbable tacks;
*other conditions, including degenerative joint disease.
For diagnosing specific pain generators details of anatomy and biomechanics are essential. One such tool is the use of a popliteus muscle test that places a load on the politeus to determine if it is causing pain.
"examiners should have a comprehensive understanding of potential pain generators about the posterior knee. While many different sources can cause posterior knee pain, review of potential causes should give providers a firm understanding of disorders to consider in their diagnostic workup."There is a nice table of disorders commonly involved in posterior knee pain, and their characteristic signs and symptoms.