Knee pain and pain behind the knee, treatment: Focus Physical✓

Pain that occurs simultaneously in the knee joint and in its posterior area (the popliteal region) represents a specific diagnostic entity because it often indicates fluid accumulation within the joint. The back of the knee is an anatomical passage for important blood vessels and nerves, but also a site where bursae are located—small fluid-filled sacs that reduce friction. When the inside of the knee is irritated due to cartilage or meniscus damage, the joint produces excess synovial fluid, which is pushed backward under pressure, creating swelling and pain.

The anatomy of the back of the knee includes the hamstring tendons, the calf muscle, and the popliteal muscle, which stabilizes the knee during rotation. Pain occurs when increased intra-articular pressure leads to the formation of a Baker’s cyst, or when the tendons passing through this region are overloaded. In individuals who engage in sports involving a lot of running or those who stand for long periods, the back of the knee is under constant tension. Understanding the connection between intra-articular damage and the appearance of posterior swelling is crucial for determining the cause of symptoms. Timely physiotherapeutic diagnosis prevents venous compression and permanent limitation of knee function.

Symptoms of pain in the knee and behind the knee vary from a feeling of tightness and fullness in the popliteal fossa to sharp pain when attempting to fully straighten the leg. Patients often report that the knee feels “tight” and that they experience pressure spreading down into the calf, especially after prolonged walking. The clinical picture is specific because swelling behind the knee can be clearly felt in a standing position, while in a sitting position, it often becomes less noticeable.

The most common symptoms accompanying pain in the knee and behind the knee include:

• A feeling of tightness behind the knee that prevents full flexion (bending) of the leg.
• Localized pain in the posterior area that increases when standing on tiptoes or squatting.
• A visible or palpable soft swelling in the popliteal fossa that may be tender to the touch.
• Occasional “locking” of the knee joint accompanied by sharp, radiating pain inside the joint itself.
• Pain spreads from the back of the knee toward the calf muscles, with occasional numbness.

These signs clearly indicate that intra-articular pressure or the soft tissues of the posterior compartment are under stress that requires professional evaluation. Early recognition of symptoms allows a physiotherapist to apply drainage techniques and relieve sensitive structures.

• Baker’s cyst
• Meniscus injury
• Knee osteoarthritis
• Deep vein thrombosis 

The causes of pain in the knee and the area behind the knee are most often associated with intra-articular pathologies that lead to fluid accumulation or direct injuries of the posterior structures. Factors such as chronic degenerative changes, sudden rotational movements, or poor flexibility of the hamstring muscles directly contribute to the occurrence of pain. Although swelling is visible at the back of the knee, the cause is almost always within the joint itself.

The main causes of pain in the knee and behind the knee are:

• Baker's cyst (popliteal cyst) is an accumulation of joint fluid in the bursa behind the knee due to joint inflammation.
• Injury of the posterior horn of the meniscus, where cartilage tearing causes specific deep joint pain.
• Gonarthrosis (knee osteoarthritis) is a degenerative process that stimulates continuous production of excess joint fluid.
• Hamstring tendinitis, inflammation of the tendons that attach to the back of the leg bones.
• Lesion of the popliteal muscle, an injury to a small muscle that is essential for unlocking the knee from full extension.

Accurately determining whether the pain is caused by a mechanical cyst or tendon inflammation allows the creation of an individualized treatment plan. Each of these causes requires a specific rehabilitation approach in order to achieve long-term reduction of pressure and pain.