Table of ContentsView AllTable of ContentsCausesConservative TreatmentsWhen to See a ProviderDiagnosisMore Invasive TreatmentsResuming Activity
Table of ContentsView All
View All
Table of Contents
Causes
Conservative Treatments
When to See a Provider
Diagnosis
More Invasive Treatments
Resuming Activity
Pain in the back (posterior) portion of the knee is relatively common. Many things could be to blame, whether it’s constant soreness in the area or simply knee pain when extending the leg. Tendon issues, cysts, injuries to the ligaments, and nerve concerns are all possible causes.
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Causes of Back of Knee Pain When Extending
Baker’s (Popliteal) Cyst
Baker’s cystsare a relatively common occurrence. They arise when an underlying knee issue, like osteoarthritis, meniscal degeneration, or a ligament tear, causes excesssynovial fluidto be produced in the joint. This fluid eventually begins to seep out of the joint’s capsule and collect in the back of your knee joint. Baker’s cysts can be slow to develop or may come on rapidly and typically cause the following symptoms:
These can rupture or leak and cause symptoms mimickingdeep vein thrombosis (DVT).
Tendon Strains or Tears
Strains or tears in several different muscles can lead to posterior knee pain when extending your leg. The most common ones include:
Strains or tears typically occur during exercise or other strenuous activities. People involved in sports involving sprinting or cutting (making sudden changes of direction), such as basketball and tennis, are particularly at risk, especially if they lack flexibility or fail to warm up properly.
Cutting or jumping movements are also commonly to blame for strains or tears of the gastrocnemius muscle.
Ligamentous Injuries
Injuries to several knee ligaments can also cause pain in the back of the knee. This includes theposterior cruciate ligament (PCL)and a group of ligaments on the outer corner of the back of the knee (calledthe posterolateral corner).
Injuries to these structures are typically sudden and occur as the result of a traumatic injury, like a car accident or a blow to the leg. In addition to posterior knee pain, injuries to the ligaments also frequently lead to leg instability and difficulty walking.
Nerve Injuries
Injuries to one of the nerves in the back of the knee can also cause pain in this area. Thecommonperonealnerveis the most frequently affected structure.
Traumas, like a blow to the knee, are the most common cause of injuries to this nerve and frequently also cause damage to multiple other muscles and ligaments at the same time. In addition to pain in the back of the knee, common peroneal nerve injuries may also cause:
Meniscal Tear
The meniscus is aC-shaped ring of cartilage that helps cushion and stabilize the knee. Whilemeniscal tearscommonly cause pain along the outer or inner part of the knee, occasionally the back area is also affected. In these situations, the posterior meniscus (called the posterior horn) is usually torn. Meniscal tears may occur gradually or as the result of a sudden twisting injury. In addition to pain, this condition can also cause:
Blood Clots
In rare instances, a blood clot ordeep vein thrombosis (DVT)may be the cause of your posterior knee pain. Some groups of people are more at risk than others, including:
Blood clots are a medical emergency and can cause the following symptoms:
How to Treat Minor Back-of-Knee Pain
Many types of posterior knee pain can be treated noninvasively. Your medical provider will typically recommend starting with conservative interventions if they suspect a minor muscle strain, a degenerative meniscal tear, a low-grade ligamentous tear, or a Baker’s cyst. Common at-home and noninvasive treatments include:
Assistive DevicesIf you are experiencing difficulty walking because of your knee pain, the following devices may help improve your mobility:CaneCrutchesRollatorWalkerWalking Stick
Assistive Devices
If you are experiencing difficulty walking because of your knee pain, the following devices may help improve your mobility:CaneCrutchesRollatorWalkerWalking Stick
If you are experiencing difficulty walking because of your knee pain, the following devices may help improve your mobility:
When Knee Pain Warrants a Provider Visit
Your knee pain may warrant a visit to a medical provider inthe following situations:
Contact Your Healthcare ProviderIt is always better to be safe than sorry. Be sure to communicate with your physician if you have any concerns about your knee pain.
Contact Your Healthcare Provider
It is always better to be safe than sorry. Be sure to communicate with your physician if you have any concerns about your knee pain.
When evaluating your knee, a medical provider will usually ask about the origins of the pain and any corresponding symptoms. In addition, several tools may be used to make a diagnosis, including:
Understanding Basic Knee Anatomy
The knee joint is wherethe femur (thigh),the tibia, andthe patella (kneecap)bones meet. Surrounding the knee are various stabilizing structures, including the joint capsule andACL,PCL,LCL, andMCLligaments. In addition, muscles like the quadriceps, gastrocnemius, hamstrings, and popliteus aid in moving the knee and provide additional stability.
Treatment for More Complex Back of Knee Pain Causes
In some cases, more invasive interventions may be needed for your posterior knee pain. More severe ligament and muscle tears often must be surgically repaired or reconstructed. Meniscal tears that do not respond to conservative treatments also frequently requirea meniscectomyoperation.
Baker’s cysts are also occasionally surgically removed or aspirated (drained of fluid), though they typically reform if the underlying cause of the cyst is not addressed.
If anticoagulant medications are not effective, a vena cava filter may need to be placed in your veins to prevent a blood clot from traveling to your lungs (called a pulmonary embolism).
When to Resume Normal Activity
The timeline to return to normal activity varies widely, depending on the cause of your knee pain. Daily activities like walking, stair climbing, and household chores should be attempted first and, only then, if they do not increase your pain significantly. After successfully reintroducing these tasks, you may be able to return to an exercise regimen gradually.
Be sure to start slowly and avoid pushing through pain. It is important to work with your medical provider before restarting strenuous activities. Beginning them too early may worsen your condition and prolong the pain.
Summary
A variety of conditions can cause posterior knee pain that worsens when you straighten your leg. This includes muscle strains, ligament tears, nerve or meniscus damage, Baker’s cysts, and blood clots. Many of these issues are well treated with conservative interventions like medications, ice, and physical therapy.
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).Massachusetts General Brigham.Hamstring injuries.English S, Perret D.Posterior knee pain.CurrRev Musculoskelet Med. 2010;3(1-4):3-10. doi:10.1007/s12178-010-9057-4Mount Sanai.Commonperoneal nerve dysfunction information.Updated 2024.American Academy of Orthopaedic Surgeons.Meniscus tears.American Academy of Orthopaedic Surgeons.Deep vein thrombosis.
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).Massachusetts General Brigham.Hamstring injuries.English S, Perret D.Posterior knee pain.CurrRev Musculoskelet Med. 2010;3(1-4):3-10. doi:10.1007/s12178-010-9057-4Mount Sanai.Commonperoneal nerve dysfunction information.Updated 2024.American Academy of Orthopaedic Surgeons.Meniscus tears.American Academy of Orthopaedic Surgeons.Deep vein thrombosis.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).Massachusetts General Brigham.Hamstring injuries.English S, Perret D.Posterior knee pain.CurrRev Musculoskelet Med. 2010;3(1-4):3-10. doi:10.1007/s12178-010-9057-4Mount Sanai.Commonperoneal nerve dysfunction information.Updated 2024.American Academy of Orthopaedic Surgeons.Meniscus tears.American Academy of Orthopaedic Surgeons.Deep vein thrombosis.
American Academy of Orthopaedic Surgeons.Baker’s cyst (popliteal cyst).
Massachusetts General Brigham.Hamstring injuries.
English S, Perret D.Posterior knee pain.CurrRev Musculoskelet Med. 2010;3(1-4):3-10. doi:10.1007/s12178-010-9057-4
Mount Sanai.Commonperoneal nerve dysfunction information.Updated 2024.
American Academy of Orthopaedic Surgeons.Meniscus tears.
American Academy of Orthopaedic Surgeons.Deep vein thrombosis.
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