title: Effect of graded bicycle seat pressure on perineal compression: a magnetic resonance imaging analysis.
abstract: OBJECTIVE
  To identify a seat pressure threshold that corresponds to significant compression of the perineum.
  
  
  METHODS
  Quasiexperimental crossover.
  
  
  METHODS
  Hospital radiology department.
  
  
  METHODS
  Convenience sample of six male recreational cyclists.
  
  
  METHODS
  Compression of the corpus spongiosum and corpora cavernosa of the perineum without bicycle seat pressure (0%) and at 10%, 40% and 80% of the mean bicycling pressure was assessed using magnetic resonance imaging. Seat pressure was applied using a custom loading device.
  
  
  METHODS
  Measure Diameter measurements of the cavernous spaces at the point of peak compression.
  
  
  RESULTS
  The mean diameter values for the corpus spongiosum in the unloaded and 10% of load conditions were 105% and 172% greater than the 40% and 80% loaded conditions, respectively (p=0.002-0.004). The corpora cavernosa values displayed a similar trend.
  
  
  CONCLUSIONS
  Substantial compression of the perineal cavernous spaces may occur with total seat pressure values of less than 40% of typical seat loads.
authors.affiliation: Biomechanics Laboratory, HPER Department, Utah State University, 7000 Old Main Hill, Logan, UT 84322, USA. eadric.bressel@usu.edu
authors.forename: Eadric
authors.initials: E
authors.lastname: Bressel
authors.forename: Dan
authors.initials: D
authors.lastname: Parker
mesh_terms: D000328:Adult; D001642:Bicycling; D004867:Equipment Design; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010502:Perineum / Q000033:anatomy & histology*; D011312:Pressure; D013314:Stress, Mechanical