Skip to main navigation menu Skip to main content Skip to site footer

Case Report

Vol. 8 No. 1 (2004)

Complete Unilateral Absence of Trapezius Muscle

  • Mohammed Allouh
  • Adel Mohamed
  • Azedean Mhanni
October 25, 2020


Congenital partial absence of the trapezius muscle is a relatively common variation. Several cases of partial absence of the trapezius muscle have been reported. However, complete unilateral agenesis of this muscle has not been previously reported. In our case, a complete cadaver dissection of an 87-year-caucasian male was performed at the Department of Anatomy, College of Medicine in Saskatoon, Canada. The entire body dissection revealed a complete agenesis of the left trapezius muscle fibers. No other significant congenital anomalies were found.


  1. Gray H. Gray's Anatomy, p 835-836. New York: Churchill Livingstone, 38th edition. 1995
  2. Johnson J, Bogduk N, Nowitzke A and House D. Anatomy and actions of the trapezius muscle. Clin Biomech 9:44-50; 1994
  3. Kierner A, Zelenka I and Burian M. How do the cervical plexus and the spinal accessory nerve contribute to the innervation of the trapezius muscle. Arch Otolaryngol Head Neck Surg 127:1230-1232; 2001
  4. Bernnan P, Smith G and Ilankovan V. Trapezius muscle innervation by a cervical nerve - a rare anatomical variant. British J Oral Maxillo Surg 40:263-264; 2002
  5. Gross-Kieselstein E and Shalev R. Familial absence of the trapezius muscle with associated shoulder girdle abnormalities. Clin Genetics 32:145-147; 1987
  6. Horan F and Bonafede R. Bilateral absence of the trapezius and sternal head of the pectoralis major muscles. J Bone Joint Surg Am 59:133; 1977
  7. Emsley J and Davis M. Partial unilateral absence of the trapezius muscle in a human cadaver. Clin Anat 14:383-386; 2001
  8. Garbelotti S, Fernando de Sousa Rodrigues C, Sgrott E and Prates J. Unilateral absence of the thoracic part of the trapezius muscle. Surg Radiol Anat 23:131-133; 2001
  9. Debeer P, Brys P and DeSmet L. Unilateral absence of the trapezius and pectoralis major muscle: A variant of Poland Syndrome. Genet Counsel 13:449-453; 2002
  10. Shamberger R. Congenital chest wall deformities. Curr Prob Surg 33:474-542; 1996
  11. Das Narla L. Pediatric case of the day-Prune-belly syndrome (Eagle-barrett syndrome, triad syndrome). Radiographics 18:1318-1322; 1998
  12. Cihak R. Musculus trapezius and the changes of its formation in human ontogenesis. Acta Univ Carol Med 20:45-66; 1974
  13. Moore K and Persaud T. Before we are born-Essentials of embryology and birth defects, p 399-405. Philadelphia: W.B. Saunders Company, 5th edition. 1998


Download data is not yet available.