title: Ultrasound assessment of asymmetric hypertrophy of the rectus abdominis muscle and prevalence of associated injury in professional tennis players.
abstract: OBJECTIVE
  To assess rectus abdominis (RA) thickness and injury prevalence using ultrasound in a group of professional tennis players. Observations with regard to muscle fiber repair is described. We likewise studied the potential link between RA volume asymmetry and the risk of muscle strain.
  
  
  METHODS
  The degree of asymmetry between the different RA slices was assessed using ultrasound in 61 professional tennis players. The history of RA injury in these tennis players was likewise studied, taking into account the following factors: dominant vs non-dominant arm, history of RA strains, duration thereof and number of recurrences. Ultrasound examination was performed with an 8- to 12-MHz linear multi-frequency transducer.
  
  
  RESULTS
  Ultrasound revealed the presence of fibrous scar tissue in the RA muscle in 18 cases (29.5%). In all instances, the lesion was located in the RA on the side of the nondominant arm. In 16 of the cases, the lesion was infra-umbilical and L2 was affected in two cases. The mean maximum width of the fibrous repair tissue was 9 mm (range 5-16). The mean distance between the umbilicus and the scar was 5.8 cm (range 2.9-11.4). Statistical study of the ultrasound measurements obtained for the different slices revealed statistically significant differences between the different depths and according to arm dominance.
  
  
  CONCLUSIONS
  In the series studied, the prevalence of RA muscle lesion in professional tennis players was 29.5%. Asymmetric hypertrophy of the RA muscle appears to constitute a risk factor for suffering an injury in this location.
authors.affiliation: Consell Català de l'Esport. Generalitat of Catalonia, Barcelona, Spain.
authors.forename: Ramon
authors.initials: R
authors.lastname: Balius
authors.forename: Carles
authors.initials: C
authors.lastname: Pedret
authors.forename: Piero
authors.initials: P
authors.lastname: Galilea
authors.forename: Fernando
authors.initials: F
authors.lastname: Idoate
authors.forename: Angel
authors.initials: A
authors.lastname: Ruiz-Cotorro
mesh_terms: D015897:Comorbidity; D005260:Female; D006801:Humans; D006984:Hypertrophy / Q000000981:diagnostic imaging / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D017568:Rectus Abdominis / Q000000981:diagnostic imaging / Q000293:injuries* / Q000473:pathology*; D012307:Risk Factors; D013030:Spain / Q000453:epidemiology; D013715:Tennis / Q000293:injuries* / Q000706:statistics & numerical data*; D014463:Ultrasonography / Q000706:statistics & numerical data*; D055815:Young Adult