Erb and Westphal

November 4, 2014

by Damiana Andonova

Wilhelm Heinrich Erb of Bavaria, an internist interested in neurology, was a professor in Heidelberg, Germany. He is most known for writing about the importance of deep tendon reflexes to the neurological exam in the January 1875 issue of Archiv fur Psychiatrie und Nervenkrankheiten.


Carl Friedrich Otto Westphal was a professor in Berlin and an editor of that journal. In January 1875, he too, wished to submit a text on the same subject to the same journal. He published his thoughts on deep tendon reflexes in the very same issue to which Erb submitted his manuscript.

And so the story goes that Westphal wrote in his paper that he had thought of the patellar tendon reflex in 1871, and that,

“during the preparation of this essay for publication, I received the preceding manuscript of Professor Erb. To my surprise, I saw that my honored friend was reporting facts that, in part, were virtually identical to those to be published by myself”.

He further claimed that while Erb noticed the deep tendon reflex (DTR) in 1870, he “only came around to a more detailed examination of the  question” later than Westphal. Oooh the controversy!

While many were familiar with deep tendon reflexes (the knee jerk reflex specifically), Erb and Westphal were the first to write about their neurologic significance.

Westphal claims to have come to the idea when a patient consulted him due to a motor weakness in the leg and certain cerebral symptoms, and once he saw a sudden jerk of the affected leg, he claims “I easily convinced myself that I was dealing here with a phenomenon that had nothing to do with imagination and which could not be duplicated in the other leg.”

On the matter of technique, Erb describes, “[DTRs] can be elicited by light tapping of the tendon of the quadriceps above or below the patella and are best produced from the ligamentum patellae”

Westphal describes, “One taps the ligamentum patellae lightly, but with rapid, brief taps-best done by placing the index finger over the middle finger and then letting it fly back with a jerk, or still more effectively with a percussion hammer-the lower leg is propelled upwards with a sudden jerk . . . one may also produce the same sign in certain cases with the subject in a horizontal bed, that is, with the knee-joint almost fully extended.”

Refer to our posts on the neuro exam, and our page on deep tendon reflexes for more information on this topic!


Erb W H. Über Sehnenreflexe bei Gesunden und Rückenmarkskranken. Archiv fur Psychiat und Nervenkrankh . 1875; 5 792-802

Louis, E. D. (2002). Erb and Westphal: Simultaneous Discovery of the Deep Tendon Reflexes. Seminars in Neurology, 22(4), 385–390. doi:10.1055/s-2002-36760

Westphal C O. Über einige Bewegungs-Erscheinungen an gelähmten Gliedern. Arch fur Psych und Nervenkrankh . 1875; 5 803-834

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