My Knee Hurts When I Bend It And Straighten It: Ultimate Guide in 2022

My knee hurts when I bend it and straighten it, what could be the cause of this? Knee pain can be something worrisome – no doubt about it. Because the knee is one of the most used joints in the body, if it is not in the right form, then it can make it difficult for you to move. Remember, your weigh relies entirely on the knee.

That means walking will be almost impossible if your knees have a problem. There are a lot of causes of knee pain, among them sprained ligaments, tendinitis, meniscus tears, and runner’s knee. Still, if you have an old knee injury that was not treated well, then it may resurface now and then.

And these conditions are painful.

My Knee Hurts When I Bend It And Straighten It

Apart from being a complex joint, and the knee is one of the largest in the body. It has moving parts – the femur (thigh bone), (shin bone) tibia, and the kneecap (patella). Movement is smooth at the knee joint because of proper arrangements and cushioning.

Further knee joint remains stable because the ligaments hold the bones together while tendons connect muscles to the bone at the joint.

Again, there is an abundance of cartilage. This cartilage is vital in absorbing shock between the femur and the tibia.

Pain at the knee when bending or straightening the leg

Feeling pain while straightening or bending your knee may be familiar to some people. However, I suggest that you address the problem before it gets worse. The problem may start suddenly, maybe after an injury, or it may develop over time, depending on the cause.

Note that some conditions may cause pain when you bend your knee only, while others may cause pain when you bend and straighten. Today we look at a condition that causes pain when you bend and straighten your knee.


Chondromalacia patellae is a common condition among athletes. It usually manifests itself in the form of a dull pain when you bend your knee or when you extend it right after bending. A grinding sound generally accompanies the pain.

Similarly, you may feel pain when:

  • You walk downstairs or hill
  • When climbing stairs
  • Straightening your knee while it is bearing weight

Chondromalacia patellae occur when there is softening or deterioration of the cartilage on the under surface of the patella. When you move up and down a staircase or a hill, you use your kneecap a lot. Actually, this is a deeper movement, which forces the kneecap to slide up and down considerably over the femur than usual.

Kneecap that has worn out cartilage won’t slide into its groove. Thus, you’ll feel pain when you bend and straighten your knees because the bones either rub on each other (no cartilage) or the bones rub on rough cartilage.

Other activities that may cause pain include when sitting down with your knees bent over 90 degrees, squatting, or kneeling. Such events only occur if you bend your knees deeply. For this reason, even if the cartilage at the knee has a small swelling, it still will stimulate pain when the activities above are done.


  • Painful ken: the pain may be around the knee area or in the knee. You feel this pain, especially you climb stairs, staying in one position for long or when you do intense activities. This kind of pain in the knee is usually called patellofemoral pain.
  • Cracking sounds or grinding sensation in your knees when you bend them, i.e., crepitus


The doctor assesses the affected knee for visible symptoms. For instance, the doctor identifies swollen areas or knee tenderness. Additionally, the doctor might look at how the kneecap aligns with the thigh bone. If there is any malalignment, then it can be a sign of chondromalacia patellae.

Still, a doctor may use resistive pressure on the extended kneecap (hyperextended knee) to determine the severity and tenderness of the knee. For the sake of clarity and proper diagnosis, the doctor may request the following tests:

  • X-rays: show the extent of bone damage, signs of misalignment or arthritis
  • Magnetic resonance imaging (MRI): to determine cartilage wear and tear
  • Arthroscopic exam: to visualize the interior of the knee. The procedure is invasive, as it involves inserting into the knee joint an endoscope and camera.


Destruction of cartilage occurs under various conditions. Surprisingly, many people may have worn-out cartilage without ever having an injury to their knee.

Common causes of chondromalacia include:

  • Excessive use of your knees
  • A knee injury
  • Weak muscles within the thighs or calves
  • A kneecap that is not well aligned

Treatment options

  • The first treatment you get involves reducing pressure on the kneecap and joint. Additionally, stabilizing, resetting, and icing is necessary.
  • Physiotherapy: to strengthen muscle for balance and strength
  • Non-weight-bearing exercises, e.g., swimming.
  • Isometric exercises
  • Arthroscopic surgery


Having a full range of motion at your knee without any pain is something desirable. Unfortunately, for many people, the pain usually creeps in, in one way or the other. It may be an injury, excessive exercising, or a strain on your knee. This can make it difficult to bend or straighten your knees. participates in the Amazon Associates Associates Program, an affiliate advertising program designed to provide a means for sites to earn commissions by linking to Amazon. This means that whenever you buy a product on Amazon from a link on here, we get a small percentage of its price.