Throckmorton sign, also known as John Thomas sign, refers to when the penis points in the direction of unilateral disease, typically of the pelvis or hip.

Throckmorton sign is a slang term used humorously by medical students and residents.

According to the first serious study of the sign published in 1988, the sign is less accurate than tossing a coin 2. This finding was supported by another subsequent study and also a meta-analysis 5,7.

History and etymology

It is named after Thomas "Tom" Bentley Throckmorton (1885-1961) 1,5, American neurologist and governor of the Iowa chapter of the American College of Physicians. He was not Governor of the State of Iowa, as is erroneously stated on several well-known websites!

In one specific Iranian institution it is known as Solooki sign, and this is only referenced in one paper, with a lack of evidence of it being used elsewhere 3.

Oram sign is also referred to in a single Scandinavian article, from Denmark, and is thought to derive from 'ormr', a word in Old Norse meaning serpent 4,5.

In France, Roy-Camille sign refers to the clinical finding in paraplegia that the penis assumes the laterality of the medullary lesion 5. It is named for Raymond Roy-Camille (1927-1994), a French orthopedic surgeon, famous for his advances in spinal surgery 6.