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.