Percussion-induced rapid rolling muscle contractions

What it means

Mechanical percussion (i.e., striking a muscle with a reflex hammer) leads to spreading waves of muscle contractions that begin proximally and spread laterally across the muscle.

Rare diseases that can present with this2

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category