Pain at the back of the knee can be worrying, especially when it hurts while straightening your leg. This pain can come from different causes, such as strained muscles, swollen joints, or injured ligaments.
Sometimes it is mild and goes away with rest. Other times, it may need medical care. In this blog, we will discuss the common causes of pain in the back of the knee when straightening the leg, treatment options, and ways to prevent it.
Common Causes of Back Knee Pain
Some common causes of back knee pain include:
Hamstring Tendonitis
When the tendons of the hamstring get inflamed, they feel tight and sore. Overuse, sports, or sudden movement can cause this. Pain often occurs when you stretch or straighten the leg.
Baker’s Cyst
This is a fluid-filled swelling behind the knee. It usually happens because of arthritis or injury. It can feel like a lump and gets more painful when you straighten your leg fully.
Popliteus Muscle Strain
The popliteus is a small muscle that helps the knee bend and stay stable. If it gets strained, you can experience mild to severe pain when you stand up from sitting, or when straightening the knee.
Meniscus Tear
The meniscus is the cartilage that cushions the knee joint. A tear in this area can cause sharp pain, swelling, and stiffness; especially when you straighten your leg.
Ligament Injuries
The posterior cruciate ligament (PCL) and other ligaments in the knee help keep it stable. If they tear or stretch, the knee may feel weak, painful, and hard to fully extend.
Arthritis
Both osteoarthritis and rheumatoid arthritis can inflame the knee. This leads to pain, stiffness, and swelling. Straightening the leg can be especially hard after rest or in the morning.
Other Serious Causes
A blood clot in the leg (deep vein thrombosis or DVT) can also cause pain and swelling whilst straightening the leg. This is a medical emergency and if you have had a previous history, seek help immediately.
Diagnosis and Treatment
Doctors may check your knee with a physical exam or imaging tests like MRI or ultrasound. Treatment depends on the exact cause. Some common ways to treat knee pain include:
- Rest and activity change to avoid more damage
- Ice and medicines to reduce pain and swelling
- Physical therapy to stretch and strengthen the knee
- Braces to support weak or unstable joints
- Surgery for severe injuries such as torn ligaments or damaged meniscus
When To See a Doctor?
If you suspect the following signs, see a doctor right away:
- Pain lasts for more than few days
- Knee is swollen or stiff
- Knee looks and feels out of place
- Pain that starts after a fall or injury
- Pain accompanied by warmth, redness and fever
Final Word
Pain behind the knee when straightening the leg can have many causes, from simple strains to more serious injuries. Most cases improve with rest, therapy, or medicines, but some may need surgery.
If the pain does not go away, or is accompanied by fever, seek medical care from The Family Pain and Wellness for immediate diagnosis and relief. Call us to book an appointment.