title: Only the nose knows: penile hemodynamic study of the perineum-saddle interface in men with erectile dysfunction utilizing bicycle saddles and seats with and without nose extensions.
abstract: OBJECTIVE
  To investigate the differential impact of straddles (A(ns) and B(ns)) and noseless two-cheek seats (A(ntcs) and B(ntcs)) on penile hemodynamics and perineal compressive forces in subjects who cycle in a stationary bicycle.
  
  
  METHODS
  Subjects underwent cavernosal artery peak systolic velocity (CAPSV) measurements after intracavernosal injection of vasoactive agents while supine, sitting upright on an examination table, straddling a saddle, sitting on a seat, and again supine. Mean perineal compression pressures recorded while straddling the saddles were compared with those while sitting upright.
  
  
  RESULTS
  No differences were found in right and left CAPSV values while supine, sitting upright on an examination table, sitting on a seat, and supine again. Right/left CAPSV (cm/second) values straddling A(ns) and saddle B(ns) (0.7 +/- 2.9/1.5 +/- 6.2 and 0/0, respectively) were significantly lower than values obtained while sitting on A(ntcs) and B(ntcs) (25.6 +/- 13.4/23.8 +/- 12.0 and 17.3 +/- 6.4/18.3 +/- 6.5, respectively) (P < 0.001). Mean perineal compression pressures (mm Hg) on A(ns) and saddle B(ns) (315.2 +/- 39 and 387.9 +/- 64.3, respectively) were significantly higher than values obtained while sitting upright on an examination table (47.6 +/- 5.2 and 46.0 +/- 8.1, respectively) (P < 0.001).
  
  
  CONCLUSIONS
  We have identified an objective test to assess if an individual bicycle rider, sitting on a certain shape of bicycle saddle or seat generates sufficient compressive forces at the perineal-saddle interface to obstruct cavernosal arterial inflow. This study also demonstrated that straddling bicycle saddles with nose extensions is associated with perineum-saddle interface compressive pressures that exceed systolic perfusion pressures, significantly diminishing penile hemodynamics.
authors.affiliation: Institute for Sexual Medicine, Department of Urology, Boston University School of Medicine, 720 Harrison Avenue, Suite 600, Boston, MA 02118, USA. munarriz@bu.edu
authors.forename: Ricardo
authors.initials: R
authors.lastname: Munarriz
authors.forename: Vincent
authors.initials: V
authors.lastname: Huang
authors.forename: Jayant
authors.initials: J
authors.lastname: Uberoi
authors.forename: Scott
authors.initials: S
authors.lastname: Maitland
authors.forename: Terry
authors.initials: T
authors.lastname: Payton
authors.forename: Irwin
authors.initials: I
authors.lastname: Goldstein
mesh_terms: D000328:Adult; D001642:Bicycling; D001783:Blood Flow Velocity / Q000502:physiology; D015992:Body Mass Index; D004867:Equipment Design; D007172:Erectile Dysfunction / Q000209:etiology* / Q000503:physiopathology*; D006804:Ergonomics / Q000295:instrumentation*; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D010413:Penis / Q000098:blood supply / Q000294:innervation / Q000503:physiopathology; D010502:Perineum / Q000098:blood supply*; D010549:Personal Satisfaction; D011312:Pressure