Contributor: Ritika Chawla, Sports-Exercise & Musculo-Skeletal Physical Therapist, Back 2 Fitness

Back pains and knee pains are very poorly managed in today's modern world. It's not the healthcare industry alone that is to be blamed for it, but even the instant-gratification society. Half-baked knowledge makes the situation even worse.

This series of articles intends to make you more informed to make better informed decisions. 

No, all knee pains aren't because of knee arthritis or ligament tears. Even if that's the cause of your knee pain, there is a very good chance you don't need a surgery. 

Pain in the back of the knee can develop either gradually due to some underlying problem or due to some sudden injury. There can be number of causes for pain in the back of the knee. The commonest ones are listed below.

Biceps Femoris Tendinopathy

Biceps femoris is a part of the Hamstring muscle, a muscle that is in the back of your thigh. Its inflammation can lead to pain behind the knee because of its attachment there, as shown in the picture below.

This injury commonly happens with excessive acceleration and deceleration activities like sprinting or kicking sports like football, where there is a sudden forcible contraction of the muscle happens.

Symptoms may include pain and tenderness around the attachment of the muscle behind the knee.

Immediate treatment can be Ice compression, Non steroidal anti inflammatory Drugs and Soft tissue release of the tight muscles.

As the tendon starts to heal strengthening of the thigh and leg muscles is the mainstay of treatment.

Popliteus Tendinopathy

This is an injury to a small muscle located at the back of the knee. Its function is to provide stability and unlock the knee during initial bending.

Popliteus  tendinopathy  can be a result of overstretching or overuse of the Popliteus  especially during  downhill running.

Patient would feel pain while fully straightening of the knee joint or during deep squats.

Treatment involves Rest, Icing with compression and use of Non Steroidal Anti Inflammatory drugs. And later Strengthening of the weak muscles surrounding the knee joint can be done.

Popliteus bursitis or Bakers cyst

Popliteus bursa is a fluid filled pouch at the back of the knee. Its inflammation is known as Popliteus Bursitis, which can be caused either by a direct hit or because of over strain to the knee.

It gives symptom due to compression of adjacent structures. In this you will find a swollen, very tender mass that is size of a golf ball, palpable behind the knee joint.

Treatment involves Icing, withdrawal from strenuous activities, and Non steroidal anti inflammatory Drugs. If symptoms still persists for a few months, aspiration of fluid may be required.

Gastrocnemius tendinopathy

Calf is made up of two muscles. The one that originates from above the knee joint is called Gastrocnemius.

Inflammation or tear of this muscle can lead to posterior knee pain. The most common cause can be Uphill running or if there is rapid increase in the mileage.

In this condition, jumping, hopping and Calf raises would give immense pain behind the knee. Local tenderness will be present on pressing the injured area.

Initial treatment includes relief of pain and swelling by giving it Rest and Ice application.

Depending on the extent of injury, a heel raise can be given if walking becomes too painful.
Some soft tissues release and gentle stretching can be started soon after the injury. 

If it’s a minor injury strengthening can be started after 24 hours of injury like heel raises and heel drops.

Radiating Pain from the Low Back

Nerve root compression in the lumbar spine (lower back) can also give pain behind the knee. Pain can also be caused by entrapment of nerves in the buttock region or behind the knee.

This gives pain radiating down the leg upto the knee or to the sole of the foot. Numbness and tingling sensation can also be associated with it which explains the neural disturbance.

Treatment of back and relieving the compression of nerve with soft tissue releases, Acupuncture, Strengthening of core and back muscles and some flexibility exercises can help in relieving knee pain.

PCL Strain

PCL strain is not a common cause for pain in the back of the knee.

Posterior cruciate ligament (PCL) starts behind the knee and runs forward to attach to the front of the knee. Its function is to hold thigh bone over the leg bone and prevents its displacement.

Injury to this ligament happens when there is direct blow to the leg leading to overextension of leg like while playing football or if person falls on the fully bent knee which is common in downhill skiers. 

Patient complains of poorly defined pain at the back of the knee with minimal swelling.
Also there will be feeling of instability in the knee joint.

Deep vein thrombosis

Pain in the back of the knee because of Deep Vein Thrombosis is not common but is very important to be aware of as it can be fatal if not managed properly and on time.

Deep vein thrombosis is a clot of blood in the vein of calf which can be a result of prolonged immobilization or post surgery. It presents as calf pain or sometimes pain behind the knee. It is important to diagnose it properly because if it is misdiagnosed, it can lead to serious injury or death. It can be confirmed by Doppler test or Venography.

Related Topics:

Common Running Injuries

Why Running is not a knee killer?

Pain! What Pain?