LCL

The LCL, or lateral collateral ligament, is a band of connective tissue on the outer side of the knee that prevents the joint from buckling outward and stabilizes the leg during weight-bearing movement.

What your LCL does and how it gets injured

Your LCL runs along the outer side of the knee, connecting the lower end of the femur to the top of the fibula. Its main job is to resist forces that push the knee inward — the kind that occur during contact sports, a fall, or any impact that loads the outside of the joint. LCL injuries typically happen when a force pushes the knee from the inner side outward, causing the outer ligament to stretch or tear. Symptoms include pain and tenderness along the outer knee, swelling, and a feeling of instability — particularly when walking on uneven ground or changing direction. The LCL is less commonly injured in isolation than the ACL or MCL, but it often tears in combination with other structures, which makes a thorough assessment important for understanding the full picture.

Why LCL injuries are frequently undertreated

Because the LCL is more stable than some other knee ligaments and many partial tears improve on their own, it's common for people to return to activity before the joint has fully stabilized. Without addressing the weakness and movement patterns that leave the outer knee vulnerable, re-injury or chronic instability tends to follow.

Why outer knee pain isn't always the same problem

Not all pain on the outside of the knee comes from the LCL — the IT band, the lateral meniscus, and the biceps femoris tendon (one of the hamstring tendons) all converge in the same region and can each produce similar symptoms. A careful assessment that traces the pattern to its source is what determines the right rehabilitation approach.

How Sword Health can help

A physical therapist can assess your LCL injury, determine what else may be involved, and guide your recovery with a targeted plan that restores stability and strength to the outer knee. Sword connects you with that care from home, at every stage of rehabilitation.