Pain in the back of the Knee: 11 Possible Causes

Written by Jamie Page
Physiotherapist, Salford University
Medically reviewed by Dr Gina Arena
Research Fellow, University of Western Australia
Reviewed on June 28, 2022

Runner holds on to the back of the knee in pain

Repetitive stress on the knee from overuse in sports and exercise can result in various conditions causing pain in the back of the knee.[1] In addition, some medical conditions such as cysts and blood clots may also present as pain or discomfort in the rear part of the knee.

The knee plays an essential role in your biomechanics. It comprises bones, cartilage, and ligaments and is surrounded by tendons and muscles. Any injury to these structures can cause pain around the knee.[2]

What other symptoms can accompany pain in the back of the knee?

Signs and symptoms that accompany knee pain may vary depending on the cause of the problem. Symptoms may include swelling and stiffness of the knee joint. Weakness and instability can occur if tendons, muscles or ligaments are affected. Popping sensations and crunching noises are also common complaints in a knee injury.

What are the causes of pain in the back of your knee?

The knee is the most complex joint in the body, and it is also common for it to hurt sometimes. However, some medical conditions such as Baker's cyst, arthritis, infection or soft tissue injuries may cause pain and may require medical attention.

1. Leg Cramps

A muscle cramp is a sudden involuntary contraction of your muscles resulting in stiffness and severe pain. It commonly affects the muscles of your legs and behind your thigh.

Although harmless, muscle cramps can be a sign of the following conditions:

  • Dehydration

  • Mineral depletion such as potassium, calcium and magnesium

  • Nerve compression

  • Inadequate blood supply

  • Liver disease

Having leg cramps is an unpleasant experience. The cramps may last for up to a few minutes and leave your muscles sore.

2. Jumper's Knee

Jumper's knee, also known as patellar tendonitis, is a painful injury due to the inflammation of the patellar tendon. Frequent running, jumping and sudden changes in direction can damage the patellar tendon resulting in tiny tears that eventually weaken and cause pain below the kneecap.[3]

3. Biceps femoris tendonitis (hamstring injury)

The hamstrings are a strong group of muscles located behind your thigh, allowing you to bend your knee and extension of your hips. Sudden overstretching during high impact activities can cause hamstring strain and tendonitis.

This type of injury is common among runners or athletes who need to run fast and change direction fast. This includes sports such as soccer, basketball, tennis and marathon.

Other symptoms of bicep femoris tendonitis include pain in the back of the knee, swelling, bruising and muscle weakness.

4. Baker's cyst

A Baker's cyst is formed when excessive joint lubricating fluids fill a bursa at the back of the knee. Too much production of these fluids can build up and form a cyst resulting in pain and swelling behind your knee.[4]

Although a Baker's cyst may go away on its own, it may still burst and cause intense sharp pain in the knee. Steroid treatment, physiotherapy and minor surgery can help control the cyst. However, it is also essential to identify the root cause of the cyst, such as arthritis, to provide an appropriate long term solution.

5. Gastrocnemius tendonitis (calf strain)

The calf muscle consists of gastrocnemius and soleus muscles. These strong muscles control essential movements of the knee and ankle joints. It helps you to bend your knee and point your feet downward.

Due to its role in movement, it is prone to strain or tear during high intensity running activities such as soccer and tennis. A strained calf muscle causes a sudden pain at the back of your leg and difficulty standing on tiptoe. Swelling and bruising can also occur.

6. Meniscus tear

The meniscus is specialised cartilage on your knee that provides a cushion between your thigh bone (femur) and shinbone (tibia). High impact activities with sudden rotation of the knee can tear the meniscus. As we age, the meniscus weakens and becomes more susceptible to damage.

A popping sensation is commonly heard or felt when you tear a meniscus. Pain and swelling may develop over time, limiting your normal activities. Locking or buckling of the knee is also a common symptom of meniscus tear, which can become troublesome for athletes.

Due to poor blood circulation around the meniscus, it may take a long time to heal and sometimes require surgery to make a full recovery.

7. Anterior Cruciate Ligament Injury (ACL)

An Anterior Cruciate Ligament (ACL) tear is a painful injury to the inside of the knee that keeps delicate stability between your shinbone (tibia) and thighbone (femur) during movements.

Most ACL tears occur during sudden stops or changes in direction while running, such as in basketball, football and soccer. Landing from an awkward jump can also strain the ACL ligament.

If you injure your ACL, you might feel or hear a popping sensation when the injury occurs. Tears in the ligament will eventually cause swelling and pain around the knee, resulting in difficulty moving the knee.

Proper rest and intensive physiotherapy is the key to treating ACL injury. In severe cases, surgery may be needed to reconstruct the ligament and restore its proper function.

8. Posterior Cruciate Ligament Injury (PCL)

The posterior cruciate ligament (PCL) is another vital ligament that keeps the stability of the knee joint. Unlike the ACL,the PCL is less likely to get injured.

Overstretching of the ligament can lead to strain or tear. The PCL is often torn by a hard blow directly in front of the knee, like in a car accident. The PCL can also be injured when you fall on a bent knee while your foot is pointed downward.

Aside from pain, a PCL injury also causes swelling and stiffness of the knee joint. Much like the ACL, intensive rehabilitation is also needed to treat PCL injuries and correct the knee joint's instability.

9. Chondromalacia

Chondromalacia occurs when the cartilage under the surface of the kneecap softens and deteriorates. This leads to abnormal grinding of joint surfaces inside the knee joint resulting in dull aching pain behind the kneecap.

A previous knee injury, arthritis or overuse are leading causes of chondromalacia. The cartilage wears down and becomes more susceptible to damage and breakdown as we age. Other symptoms include a grinding or cracking sensation during bending or straightening the knee.

10. Arthritis

Certain medical conditions and degenerative diseases may result in arthritis. Arthritis is a condition where the cartilage that cushions and supports the joint slowly wears down.

Depending on the type of arthritis that you have, you may be given pain medications or exercise prescriptions to help manage the symptoms. Inflammatory types of arthritis, such as Rheumatoid arthritis, may require particular drugs to tone down your body's immune response.

11. Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a condition that happens when a blood clot forms in the deep veins where the blood passes. These clots may develop in the lower leg, thigh, pelvis, or arm.

It is vital to stay alert to the following symptoms of DVT:

  • Warmth in the area of DVT

  • Swelling of the leg

  • Redness

  • Tenderness

DVT can be a life-threatening condition and requires immediate medical attention. A clot can dislodge and travel to lodged in the lungs' vital arteries, causing pulmonary embolism.

Medicines that act as blood thinners can prevent the clot from getting bigger and stop new clot formation. Consult a medical doctor if you have signs and symptoms of DVT.

Home remedy for pain in the back of the knee

  • Allow your body enough rest until your knee heals

  • Apply ice compress or ice pack for 20 minutes, several times a day

  • Wear knee support or compression bandage to add support to the knee

  • Elevate the knee above the level of the heart when lying down to minimise swelling

  • Use assistive devices such as crutches or a cane to relieve some weight on the knee when walking

  • Do your prescribed exercises

Consult a physiotherapist

Knee pain can go away on its own. But if you are having persistent pain that gets worse over time, it is best to consult a physiotherapist for treatment.

Physiotherapists can help you determine the root cause of your symptoms and provide appropriate solutions to your medical condition.

You should seek immediate medical attention if you are experiencing the following:

  • Severe pain that doesn't go away.

  • Sudden swelling of the legs

  • Trouble breathing

  • Fever

  • History of blood clots

  • Instability of the knee joint

  • Unexplained changes in the appearance of the knee joint

Written by Jamie Page
Physiotherapist, Salford University
Published on June 28, 2022
Medically reviewed by Dr Gina Arena
Research Fellow, University of Western Australia
Reviewed on June 28, 2022
Medical reviewers
Last medically reviewed on June 28, 2022 has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.
Content Disclaimer
This content is general in nature and is for informational purposes only - it does not constitute medical advice. Content on is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Read more from our Content Disclaimer. is Australia’s #1 physiotherapy booking site. We aim to help everyday Australian’s access reliable, evidence-based health information and suitable treatment options via our booking engine.

Head office 2/11 York Street, Sydney NSW 2000

Questions about our product or services?

Call us Monday - Friday 9am - 6pm AEST

(02) 9068 6658

  • Blog is a Local Physio Network Pty Ltd Company. All rights reserved. Our website services, content, and products are for informational purposes only. does not provide individual medical advice, diagnosis, or treatment.
See additional information

Proudly supported by the nsw government

We’ve got your back, and whatever else hurts too™. Join our mail list for new and up to date health articles.