Why Can You Hear or Feel Tendons Flicking Over Bone? Understanding Snapping Syndromes

A Common, Often Startling Sensation

An audible click, snap or clunk — sometimes felt as much as heard — occurring with specific movements around a joint is a common presentation, with the hip being one of the best studied examples (so-called "snapping hip syndrome").

A Tendon Moving Rapidly Over a Bony Prominence

In the classic external form of snapping hip, the iliotibial band or the gluteus maximus tendon catches and then suddenly releases as it passes over the greater trochanter of the femur during hip flexion and extension; in the internal form, the iliopsoas tendon catches over the front of the hip joint or pelvis. Dynamic ultrasound imaging of elite dancers with this presentation directly confirmed the mechanical tendon-over-bone snapping mechanism in real time (Winston et al., 2007).

When It's Benign Versus When It Needs Assessment

A painless snap, present for years without other symptoms, is generally considered a benign mechanical phenomenon requiring no treatment. A snap accompanied by pain, weakness, or a sense of instability warrants a proper assessment, as it may indicate that the repetitive friction has begun to irritate the tendon or underlying bursa, or that the mechanics producing the snap are themselves linked to an underlying strength or movement-pattern deficit.