What Causes Lateral Knee Pain?

Monday, August 31, 2020

Pain on the outside of your knee can be debilitating and tough to treat. This pain is known as lateral knee pain, or in other words, any pain you might feel outside or around your actual knee joint.

Figuring out the cause of your lateral knee pain is a great place to start toward a treatment plan that works. So, what causes lateral knee pain? Let's dive into it.

Causes of Lateral Knee Pain

Iliotibial Band Syndrome

The iliotibial band is a thick band of fascia that crosses the hip joint, extends along the side of your thigh, and attaches the patella, tibia, and biceps femoris tendon. Repetitive flexion and extension of the knee can cause the iliotibial band to become inflamed and creates lateral knee pain.

Also known as ITBFS or runner's knee, iliotibial band syndrome develops gradually over time and creates symptoms such as:

  • Pain and inflammation on the outside of your knee
  • Symptoms are more evident while performing activities like running and usually subsides during rest

What Causes Lateral Knee Pain?

Lateral Cartilage Meniscus Injury

Your meniscus is a small semi-circular disc of cartilage found in your knee joint. A torn meniscus can come on gradually due to wear and tear, or it can be acute as a result of a sudden injury.

Symptoms of a lateral cartilage meniscus injury include:

  • Pain on the outside of your knee along the joint itself
  • Increased pain when bending the knees, like in a deep squat
  • Swelling around the knee joint
  • The knee may lock or give way

What Causes Lateral Knee Pain?

Lateral Collateral Ligament Sprain

A lateral collateral ligament (LCL) injury is another common cause of lateral knee pain. This ligament is located on the outer side of your knee. Injury to this ligament can come on gradually, but it's more likely that a tear or sprain might occur as a result of sudden impact.

Twisting your knee or a direct blow to the side of your knee can cause an LCL tear or sprain which will undoubtedly cause lateral knee pain.

Other symptoms of an LCL injury include:

  • Swelling of your knee
  • Bruising around the joint
  • Stiffness in your joint
  • Instability of the knee joint

What Causes Lateral Knee Pain?

Patellofemoral Pain

Patellofemoral Pain Syndrome (PFPS) causes pain at the front of your knee and around your patella (kneecap). PFPS is caused when your patella is out of alignment and rubs on your femur (thigh) bone.

Symptoms of PFPS include:

  • Aching pain in your knee
  • Tenderness and swelling mostly near your kneecap
  • Increased pain when walking upstairs, downhill, or after sitting for an extended period

What Causes Lateral Knee Pain?


Osteoarthritis refers to the degeneration of cartilage in your joints due to wear and tear. For that reason, the condition is more common as we age and eventually, even the bone begins to wear away.

In terms of lateral knee pain, symptoms of osteoarthritis include:

  • A deep ache in the knee joint
  • Worsened symptoms after exercise
  • Swelling and stiffness in the joint


What Causes Lateral Knee Pain?

Biceps Femoris Tendinopathy/Tendinitis

Your biceps femoris is part of your hamstring and it's a large tendon that can become inflamed or begin to degenerate, both resulting in lateral knee pain. This tendon attaches to the back of the knee joint causing pain in that area.

Symptoms of biceps femoris tendinopathy/tendinitis include:

  • Tenderness, pain, and swelling at the back of the knee
  • Symptoms are typically worse first thing in the morning or after extended periods of sitting


Synovitis may also contribute to lateral knee pain. The synovial membrane is responsible for providing synovial fluid which lubricates the knee joint. Synovitis occurs when the synovial membrane in the knee becomes inflamed.

Symptoms of synovitis include swelling and stiffness in your knee and the inflammation is often the result of a knee injury, arthritis, or gout.

What Causes Lateral Knee Pain?

Superior (Proximal) Tibiofibular Joint Dislocation

Your tibiofibular joint is the joint where your knee meets the top of your shin bone. A dislocation of the tibiofibular joint is incredibly painful and is normally caused by an impact to the knee while in a fully bent position.

Symptoms of a superior tibiofibular joint dislocation include:

  • Pain and swelling near the shin bone
  • A protrusion of the shin bone in relation to your knee joint

Referred Knee Pain

Your lateral knee pain may also be caused by other parts of your body. Particularly, sciatic pain caused in your hips or lower back can travel down to your knee causing lateral knee pain.

Less Common Causes of Lateral Knee Pain

Although uncommon, these are a few other causes of lateral knee pain:

  • Peroneal Nerve Injury
  • Slipped Captial Femoral Epiphysis
  • Perthes' Disease
  • Baker's cyst

Treating Lateral Knee Pain

Many of the aforementioned conditions, especially if its onset is gradual, are caused by overuse and poor training habits. For example, adding too heavy a load, too quickly or suddenly increasing the intensity of your workouts can be bad news for your knees.

Even playing sports on uneven, poorly maintained fields can cause major lateral knee pain. Of course, structural abnormalities can also prove to be the culprit, but most often, you can work with a Exercise Physiologist to fix any habits that aren't serving you.

When you visit your physiotherapist to treat your lateral knee pain, you'll likely be working on various knee flexion exercises using proper form. By increasing flexion of the knee and improving its range of motion, you're also less likely to experience an injury since you'll have the tools to protect your knees from further damage, therefore relieving lateral knee pain.

For example, by applying pressure to the fibula and manually rotating the lower leg posteriorly, your physiotherapist can help increase the range of motion in your knee flexion with less lateral knee pain. If this therapy method helps, your physiotherapist can then use kinesthetic tape to hold the posterior rotation of the fibula in place for about 48 hours, giving your knee more range of motion while allowing your body to heal.

Check out our video going into more detail about this process

If you're experiencing any pain on the outside of your knee, definitely give Physio Inq a call. We can set you up with one of our physiotherapists who can help. Book an appointment at any of our convenient Australia locations or let our mobile physio services come to you!

This article was originally written by Jonathan Moody from Physio Inq

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