To the Editor:
“The Popeye sign,” described in the Journal as a marked bulge in the upper arm after rupture of the biceps tendon (1), should more correctly have been called “a Popeye sign,” given that the term “Popeye arm” has also been applied to patients with fascio-scapulo-humeral muscular dystrophy who have wasting of the biceps combined with preserved deltoid and forearm musculature (2).
The confusion is understandable to anyone familiar with Popeye-the-Sailorman’s complex and dynamic upper limb anatomy. In his baseline state, Popeye exhibited the forearm muscular hypertrophy common among sailors of his era (the 1930s), for whom scraping paint was a frequent duty (3). To science’s detriment, the instantaneous biceps hypertrophy that Popeye experienced after oral spinach ingestion remains physiologically unexplained.
Thus, for maximal clarity, an eponymical purist would use the terms “pre-spinach Popeye sign” and “post-spinach Popeye sign,” respectively, in cases of fascio-scapulo-humeral muscular dystrophy and biceps tendon rupture.
(1) Yoshida N, Tsuchida Y. "Popeye" sign. Images in clinical medicine. N Engl J Med. 2017; 377: 1976.
(2) Case records of the Massachusetts General Hospital, Case 40-1991. N Engl J Med. 1991; 325: 1026-1035.
(3) Hornfischer JD. The Last Stand of the Tin Can Sailors. New York: Bantam Dell, 2005. Page 90.