Pain Behind The Knee (Posterior)
Posterior knee pain is pain at the back of the knee. Below we outline the most common causes of pain at the back of the knee, less common causes as well as important conditions and injuries that should not be missed. Biceps femoris tendonitis (hamstring tendonitis) is probably the most common over use injury at the back of the knee although referred pain and various causes of swelling are also likely causes of pain at the back of the knee.
Gastrocnemius tendinopathy or tendinitis is inflammation or degeneration of the tendon of the calf muscle causing pain at the back of the knee. This is an overuse injury which is more common in runners and sprinters.
The biceps femoris tendon is one of the hamstring muscle tendons. Injury to this tendon causes pain at the outside, back of the knee.
A Baker's Cyst or Popliteal cyst is a prominent swelling at the back of the knee. It is usually caused by an underlying injury or condition in the knee joint.
Tennis leg is a general term used to describe pain in the leg caused by a tear of the inner head of the big calf muscle, the plantaris muscle or sometimes both.
Posterolateral corner injuries cause pain at the back and outside of the knee. They are not particularly common injuries, although around half of cases occur due to sporting injuries, with road traffic accidents being another common cause.
The Popliteus is a small muscle located at the back of the knee joint. An injury or strain to the muscle or tendon can cause pain at the back of the knee.
Less common causes of posterior knee pain
Referred pain is where an injury or problem elsewhere causes pain at the back of the knee. This can be from the lower back or lumbar spine and pain is referred down into the knee through the sciatic nerve. Or pain from the patellofemoral joint or between the kneecap and thigh bone can also refer pain into the back of the knee.
Popliteus tendonitis or injury is inflammation or injury to the small muscle at the back of the knee called the popliteus. The role of the popliteus muscle is to internally rotate the tibia or shin bone. Symptoms include pain at the back of the knee joint with tenderness when pressing in. Pain may be reproduced when the knee is bent against resistance whilst the lower leg or tibia bone is rotated outwards.
Gastrocnemius tendonitis is inflammation of the tendon of the large calf muscle at the point it originates at the back of the knee. This is an over use injury and usually affects the inside back of the knee joint where the muscle originates.
Important do not miss
Deep vein thrombosis or DVT as it is known for short is a blot clot in a vein common in the calf muscle. It usually occurs following surgery or a long period of immobilization in the calf muscle itself although can occur in the back of the knee. It is very important this is not missed or confused with a calf strain as serious injury or death could result if wrongly treated.
Posterior cruciate ligament injury is a tear or sprain to the posterior cruciate ligament at the back of the knee. The role of this ligament is to prevent the knee from bending back the wrong way and is usually injured when the knee is forced to do just that. Symptoms include pain at the time of injury with possibly a little swelling depending on how bad the injury is. The athlete may complain of the knee feeling unstable and giving way beneath them.
Claudication is pain or cramping in the legs due to insufficient blood flow and / or tiredness.