Pain in the back of the knee, treatment: Focus Physical✓

Pain occurring on the back of the knee, in the region known as the popliteal fossa, often causes a sensation of tightness and pressure that limits the full mobility of the leg. This region is an anatomical crossroads through which the leg's largest blood vessels and nerves pass, protected by a layer of fatty tissue and the powerful tendons of the thigh and calf muscles. Unlike pain on the front of the knee, back pain is frequently associated with fluid accumulation within the joint or issues with the muscle attachments that control knee stability during walking.

The anatomy of the back of the knee includes the tendons of the hamstrings and the calf muscle (gastrocnemius), which attach to the bones in this area. Between these muscles lies the popliteal muscle, a key stabilizer that "unlocks" the knee at the start of flexion. Inside the fossa itself are small fluid-filled sacs called bursae that facilitate the gliding of tendons.

Any internal knee injury, such as meniscus damage, can lead to increased secretion of joint fluid that is pushed backward, creating a characteristic pressure. Understanding the connection between the internal structures of the joint and the soft tissues of the popliteal fossa is crucial for determining the cause of the discomfort. Timely physiotherapeutic diagnostics and the application of targeted procedures prevent chronic swelling and loss of leg function.

Symptoms of pain on the back of the knee vary from a dull sensation of fullness and pressure to sharp pain that occurs when attempting to fully straighten the leg. Patients often report the feeling of a "foreign body" behind the knee, which makes squatting or prolonged walking difficult. The clinical picture is specific because, in some cases, a soft protrusion can be felt that changes depending on the position of the leg.

The most common symptoms accompanying pain in the back of the knee include:

• A sensation of tightness and pressure in the popliteal fossa that intensifies when the leg is fully extended.

• The appearance of a visible or palpable swelling (cyst) on the back side, which may feel soft to the touch.

• Pain radiating down the calf muscle or upward toward the back of the thigh during physical activity.

• Limited range of motion, especially the inability to bring the heel toward the glutes when bending the leg.

• Occasional numbness or weakness in the foot may indicate that the swelling is pressing on nerves in the popliteal fossa.

These signs are clear indicators that the posterior structures of the knee are under strain or pressure from excess joint fluid. Recognizing these symptoms in time allows the physiotherapist to apply drainage and offloading techniques, preventing the rupture of a cyst or permanent muscle shortening.

• Baker's cyst
• Posterior cruciate ligament injury
• Inflammation of the hamstring tendon
• Meniscus injury

The causes of pain at the back of the knee are most often secondary in nature, meaning that pain in the popliteal fossa is a consequence of another problem within the joint itself. Factors such as chronic cartilage inflammation, meniscus injuries, or sudden strains of the hamstring muscles directly contribute to the onset of discomfort. Although the pain is felt at the back, the cause is often hidden in mechanical damage to the front or middle part of the knee.

The primary causes of pain in the back of the knee include:

• Baker’s Cyst (Popliteal Cyst): An accumulation of joint fluid in the bursa behind the knee due to joint inflammation or injury.

• Hamstring Tendinitis: Inflammation of the tendons of the muscles that attach to the back of the knee, usually due to overexertion.

• Injury to the Posterior Horn of the Meniscus: Damage to the cartilage that causes localized pain deep in the posterior part of the joint.

• Popliteus Muscle Inflammation: Causes pain during the initial degrees of leg flexion or rotation of the lower leg.

• Vascular or Neurological Issues: Such as compression of the popliteal artery or irritation of the tibial nerve.

Precisely identifying the cause of the pressure allows for the creation of an individual treatment plan that will permanently eliminate the pain and the underlying cause of the swelling. Each of the mentioned causes requires a specific rehabilitation approach to achieve long-term relief and prevent recurrences.