title: The Prevalence of Absence of the Palmaris Longus Muscle Tendon in the North of Iran: A Comparative Study.
abstract: BACKGROUND
  The palmaris longus is a degenerating weak flexor muscle in the anterior of the forearm. Many techniques for clinically determining the presence of the palmaris longus have been described. Ethnic variations in the prevalence of the absence of the palmaris longus are well known.
  
  
  OBJECTIVE
  This study considered the prevalence of absence of the palmaris longus muscle tendon in the north of Iran.
  
  
  METHODS
  The presence of the palmaris longus was clinically determined in 562 men and women from the Guilan population, using the standard technique (Schaeffer's test). In subjects with an absent palmaris longus, three other tests (Thompson, Pushpakumar and Mishra tests) were performed to confirm the absence.
  
  
  RESULTS
  The overall prevalence of right, left, bilateral and total absence of the palmaris longus were 4.1%, 5.2%, 3.9% and 13.2%, respectively. There was no significant difference in its absence with regard to the body side or gender (P > 0.05).
  
  
  CONCLUSIONS
  This study demonstrated that the presence of the palmaris longus muscle tendon in the Guilan population was considerably higher than the absence of the palmaris longus tendon. The overall prevalence of right, left, bilateral and total absence of the palmaris longus was not significantly different between men and women. The prevalence of the left-absent palmaris longus was more common in the present study.
authors.affiliation: Department of Anatomy, School of Medicine, Guilan University of Medical Sciences, Rasht, IR Iran.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Nasiri
authors.affiliation: Department of Anatomy, School of Medicine, Babol University of Medical Sciences, Babol, IR Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Pourghasem
authors.affiliation: Department of Biochemistry and Medical Physics, Guilan University of Medical Sciences, Rasht, IR Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Moladoust
keywords: Iran; Muscles; Prevalence; Sex; Tendons