Knee valgus

Also known as: dynamic knee valgus, knee collapse

An inward collapse of the knee toward the midline during the stance phase of running.

Why it matters

Knee valgus increases patellofemoral joint stress with every stride, and it's one of the most common form faults seen in runners with anterior knee pain.

What it means

Knee valgus is driven by hip abductor weakness and ankle stiffness. It increases patellofemoral compression and is treated with hip and glute strengthening rather than knee-focused work. It's often most visible on a single-leg squat or during the landing phase of running gait video, viewed from the front or rear.