Westphal Sign

Excerpt

Westphal’s sign refers to a decreased or absent patellar tendon reflex, also known as the knee-jerk reflex, observed on physical exam. The patellar tendon reflex refers to a kicking-like motion produced by the extension of the knee joint upon the ipsilateral stimulation of the patellar tendon. The reflex is thought to play a role in maintaining balance. The realization of the importance of deep tendon reflexes in the physical exam is often attributed to Wilhelm Heinrich Erb and Carl Friedrich Otto Westphal, who both noted this finding in the late 1800s. Westphal’s sign thus receives its name from Carl Friedrich Otto Westphal. The patellar tendon reflex is a deep tendon reflex, similar to the biceps, brachioradialis, triceps, Achilles, and jaw jerk reflexes.