Dr Jacob Mackiewicz (1887-1966) and his sign.

Dr Jacob Mackiewicz, a Jewish-Polish neurologist, described the cruralis phenomenon related to injury of the femoral nerve or of the fourth lumbar root. In 1912, only one year after graduation maxima cum laude from Moscow University, the 25-year-old Dr Jacob Mackiewicz described the cruralis phenomenon, regarded in the German and Slavic medical literature as the Mackiewicz sign: 'the patient lies prone, the examiner lifts the thigh in one hand, with the other hand, bends the patient's knee slowly; this manoeuvre causes severe pain in the anterior part of the thigh and over the groin. This manoeuvre indicates a femoral nerve injury'.