Pain on the outside of the knee, called lateral knee pain, usually comes from the iliotibial (IT) band, the lateral collateral ligament (LCL), the outer meniscus or arthritis in the outer half of the joint. How it started is the most telling clue: a gradual ache during running or cycling points to the IT band, while a blow, twist or pop points to a ligament or meniscus injury. A physical therapist can tell these apart by examination and refer you for imaging if a ligament or meniscus injury looks likely.
Last reviewed By the Monon Therapy Collective editorial team
Did your outer knee pain start gradually or with an injury?
Gradual onset during repetitive activity, such as running, cycling or long hikes, usually means an overuse problem, most often IT band syndrome. A sudden start with a fall, a tackle, a twist or an audible pop points toward a ligament or meniscus injury and deserves an examination sooner.
OrthoInfo explains that LCL tears come from force to the inner side of the knee that pushes it outward, and they cause outer-knee pain and a feeling that the knee is giving out. Meniscus tears, by contrast, often let you keep walking at first, then stiffen and swell over two to three days and may catch or lock.
| Likely cause | What it tends to feel like | Where to read more |
|---|---|---|
| IT band syndrome | Sharp or burning pain just above the outer joint, at a set point in a run or ride | IT band syndrome |
| LCL sprain | Tender along the outer edge after a blow or twist; may feel wobbly | LCL sprain |
| Lateral meniscus tear | Pain on the outer joint line with twisting or deep squats, catching, swelling | Meniscus tear |
| Lateral compartment arthritis | Achy, stiff outer knee, worse after rest and long walks | Knee osteoarthritis |
Why does the IT band hurt more on downhills and on a bike?
IT band pain tends to peak when the knee repeatedly bends to a shallow angle under load, which happens with every stride downhill and every pedal stroke. A saddle set too low or too high, or a cleat angled awkwardly, can bring it on in cyclists.
Runners who add hill repeats, or cyclists who suddenly lengthen weekend rides on the Monon Trail as the weather warms, are typical examples. Pain that begins at a predictable point in the session and fades with rest is the pattern a therapist will ask about.
Can I check the outside of my knee myself?
You can gather useful clues: press along the outer edge of the knee with the leg straight, then bent, and note the most tender spot. Tenderness a little above the joint line fits the IT band; tenderness right on the joint line, especially with a deep squat, fits the meniscus.
Also check whether the knee swells, catches or feels unstable when you step sideways, as in a pickleball shuffle or getting out of a car. These notes help your therapist, but they do not replace the ligament and meniscus tests a clinician performs.
How do physical therapists examine lateral knee pain?
The examination includes stress tests of the LCL, meniscus provocation tests, palpation of the IT band and the outer joint line, and a look at hip strength and single-leg control. If the outer knee pain also tingles or runs down the shin, the therapist checks the nerve that wraps around the top of the outer calf and the lower back.
Overuse problems are usually treated with a short reduction in the aggravating activity, progressive hip and thigh strengthening and a graded return. A suspected ligament tear or a knee that locks is referred for a physician’s opinion and imaging. Exercises such as the clamshell and monster walk are common early choices for hip control, chosen and dosed by your therapist.
What should I do this week about outer knee pain?
Cut the activity that provokes it by about half rather than stopping completely, avoid deep squats and long downhill stretches for now, and keep walking on flat ground. Ice or a short course of over-the-counter pain relief is reasonable if it suits you.
If it has not improved in two to three weeks, or it started with an injury, book an examination. The knee pain physical therapy page describes what a course of care involves, and the questionnaire lets you choose “knee” so the matching team knows where to start.
Outer knee pain that needs urgent attention
- The knee buckled with a pop and swelled within hours.
- You cannot bear weight or fully straighten the knee.
- You have numbness or weakness lifting the foot, so the toes drag.
- The knee is red, hot and swollen, or you have a fever.
If you think it is an emergency, call 911.
