open access
The ulnar head of the pronator teres muscle originating from the third head of the biceps brachii: a very rare case
Affiliations- Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland
- Department of Anatomical Sciences, St. George’s University, Grenada
- Department of Neurosurgery, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Department of Neurology, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Department of Surgery, Tulane University School of Medicine, New Orleans, Louisiana, United States
- Department of Neurosurgery, Ochsner Medical Center, New Orleans, Louisiana, United States
open access
Abstract
The biceps brachii is located in the anterior compartment of the arm, which can show numerous morphological variations. During anatomical dissection, an interesting additional muscle was found: the third head of the biceps brachii originated from the short head of the same muscle. The 97.77 mm long muscle belly was directed medially over the arm and then passed into the common tendon (15.97 mm), which thereafter split into aponeurosis and tendon. The 26.33 mm aponeurosis passed and joined the fascia of the forearm. The tendon of the third head of the biceps brachii then gave rise to the ulnar head of the pronator teres muscle. Such an accessory structure could cause neurovascular compression involving the brachial artery and median nerve. Knowledge of the morphological variability of this region is essential not only for anatomists but also for clinicians.
Abstract
The biceps brachii is located in the anterior compartment of the arm, which can show numerous morphological variations. During anatomical dissection, an interesting additional muscle was found: the third head of the biceps brachii originated from the short head of the same muscle. The 97.77 mm long muscle belly was directed medially over the arm and then passed into the common tendon (15.97 mm), which thereafter split into aponeurosis and tendon. The 26.33 mm aponeurosis passed and joined the fascia of the forearm. The tendon of the third head of the biceps brachii then gave rise to the ulnar head of the pronator teres muscle. Such an accessory structure could cause neurovascular compression involving the brachial artery and median nerve. Knowledge of the morphological variability of this region is essential not only for anatomists but also for clinicians.
Keywords
anatomical variations, biceps brachii, third head
About this articleTitle
The ulnar head of the pronator teres muscle originating from the third head of the biceps brachii: a very rare case
Journal
Issue
Article type
Case report
Published online
2021-11-09
Page views
296
Article views/downloads
162
DOI
10.5603/FM.a2021.0122
Pubmed
Keywords
anatomical variations
biceps brachii
third head
Authors
Ł. Olewnik
N. Zielinska
B. Szewczyk
R. S. Tubbs
