Study of Bicycle Seat Effects on Male Perineal Blood Flow
Condition: Effect of Bike Seats on Male Perineal Blood Flow
Study type: Observational

Summary: 
      The objective is to study the effects of bicycle riding and bicycle seats on blood flow to a
      man's reproductive organs. It has been shown that bicycle riding can affect a man's ability
      to have an erection. Each year, newer and better bicycle seats come out but these seats have
      not been adequately studied for their effects on blood flow in the genital region.
    

Detailed description: 
      Introduction:

      An independent market research company released a report in 1997, estimating the bicycling
      industry to be worth an astounding 4.5 billion dollars.(1) The magnitude of this number gives
      us an idea of the popularity of this sport. An important component of a bicycle is its
      saddle, which can affect comfort, performance, and the rider's health. Several studies have
      reported sexual side effects in male bicyclists, more specifically temporary genital numbness
      and erectile dysfunction. Goldstein et. al claimed in their article that prolonged pressure
      on the perineal region causes arterial damage resulting in erectile dysfunction in men. These
      results have triggered bike manufacturers to come up with various saddle designs that claim
      to reduce risks for men. For this project investigators want to correlate bike riding and its
      effects on the male reproductive organs by measuring the pressures exerted on the perineum
      and blood flow while cycling. Previous studies on this matter have shown that a higher
      percentage of bicyclists are effected by Erectile Dysfunction(ED) compared to the general
      population. There are many published studies on the hemodynamics of the penis using Pulse
      Oximetry, Doppler Ultrasound and CAPSV measurements. Investigators goal is to be able to
      measure the pressures exerted on the arteries supplying the penis via the saddle over the
      perineum. A study, which attempted to carry out a measurement similar to this, used pressure
      transducers placed on the saddle of a stationary bike. There are flaws in this study, which
      investigators want to improve upon in designing this research experiment. For example,
      placing the sensors on the saddle enables measurements of force on the saddle and does not
      directly relate to the pressures exerted on the perineum. In other words by placing the
      sensors on the saddle researchers will not be able to distinguish between the pressures
      exerted on the perineum and other body parts in contact with the sensors on the seat, such as
      the sit bones. Also, while using a stationary bike the physics of the body and forces on the
      perineum are very different compared to road bikes on the road and mountain bikes on rough
      terrain. Investigators study corrects these flaws.

      Purpose of study:

      Can investigators measure the blood flow to the perineum via the perineal arteries and see
      the effect of bicycle riding on the blood flow through these arteries?

      Design:

      This is a pilot study which involved 2 steps to determine perineal blood flow and how bicycle
      seats affect this flow. The first step will be to use doppler ultrasound to measure the
      perineal blood flow in the Ultrasound suite of the University Illinois Chicago Medical
      Center. At this visit, patients will be asked to lie down in a frog-leg/lithotomy position on
      an exam table to allow access to the perineum. The linear ultrasound probe (L12-55) will be
      used to measure the flow through the perineal/cavernosal arteries. By applying sequentially
      increasing pressure, the critical pressure for occlusion will be measured along with flow
      rates at various applied perineal pressures. The second step will involve a bicycle ride
      where perineal pressures will be measured. Investigators use disposable sensors and tegaderm
      to stick the sensors on the perineum. No shaving of the perineum will be required so long as
      the sensor is able to be secured. The recording device is credit card size and will attach to
      the bicycle. The subjects ride using six different bike seats in a standard road course and
      also on a stationary trainer. This will conclude the requirement of the patient. The
      pressures obtained on the bicycle ride will be compared to the critical occlusion pressures
      and flow-pressure relationships measured in the ultrasound suite.

      Recruitment:

      Patients will be recruited for the project via various bicycle meetings. Cyclist will be
      approached via oral presentation and they will be men between ages 18-64, avid cyclists and
      will not be at risk of undue influence (i.e. UIC students). Please see attached recruitment
      script.

      Risks Involved:

      The study involves minimal risk to the subject as the subject will already be a cyclist and
      will be used to the mild exercise involved of cycling. Sensors will not use any electric
      input and the patient is at no harm from them. All data will be acquired using noninvasive
      radiology, ultrasound with doppler.
    

Observational model: Case-Only
Time perspective: Cross-Sectional
Sampling method: Non-Probability Sample
Study population: 
        Volunteers will be recruited from the general population. Recruitment will be done using
        oral presentation, meetings, advertisement flyers.Participants will be avid cyclists and
        will not be at risk of undue influence( i.e UIC students).
      
Keywords: bike seats; Erectile dysfunction; Perineum; Impotence