title: Sonographic measurement of achilles tendons in asymptomatic subjects: variation with age, body height, and dominance of ankle.
abstract: OBJECTIVE
  This study was undertaken to evaluate the thickness, cross-sectional area, and length of Achilles tendons in asymptomatic subjects of different age groups and heights and between dominant and nondominant ankles.
  
  
  METHODS
  High-resolution sonographic examinations of Achilles tendons were performed in 40 healthy subjects (14 men and 26 women). The subjects were categorized into 4 age groups: (1) 20 to 29 years, (2) 30 to 39 years, (3) 40 to 49 years, and (4) 50 years or older. The thickness, cross-sectional area, and length of the Achilles tendons of both ankles were measured. All Achilles tendons were measured with the ankle in a relaxed, neutral position.
  
  
  RESULTS
  There was no significant difference in the thickness and length of Achilles tendons among subjects of different age groups (P>.05). The Achilles tendon cross-sectional area of subjects 50 years or older was significantly larger than that of subjects in the younger age groups (P<.05). There was a positive correlation between the height of the subjects and the length, thickness, and cross-sectional area of the Achilles tendons; however, the correlation coefficient was low (r=0.07-0.28; P>.05). Dominance of ankles did not affect the thickness and length of the Achilles tendons, whereas the cross-sectional area of the tendons was significantly larger in the dominant ankles (P<.05).
  
  
  CONCLUSIONS
  Sonography is a useful imaging tool in the evaluation of Achilles tendons. Normal variations of the tendon morphologic characteristics should be considered in the clinical diagnosis.
authors.affiliation: Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
authors.forename: Beatrice S F
authors.initials: BS
authors.lastname: Pang
authors.forename: Michael
authors.initials: M
authors.lastname: Ying
mesh_terms: D000125:Achilles Tendon / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D014463:Ultrasonography