Digital three‐dimensional modelling of the male pelvis and bicycle seats: impact of rider position and seat design on potential penile hypoxia and erectile dysfunction

Abstract

RESULTSPelvis/seat models suggest that the most likely site of compression of the internal pudendal artery is immediately below the pubic symphysis, especially with the rider leaning forward. For an upright rider, the internal pudendal arteries do not appear to be compressed between the seat and the bony pelvis. Leaning partly forward with arms extended, the seat/symphysis areas were reduced to 73 mm 2 with standard seat and 259 mm 2 with a grooved seat. Leaning fully forward, the seat/symphysis areas decreased (no space with standard seat; 51 mm 2 with a grooved seat) and both the ischial tuberosities and the pubic symphysis might be in contact with the seat. CONCLUSIONA grooved seat allows better preservation of the seat/symphysis space than a standard seat, but the rider's position is more important for preserving the seat-symphysis space (and reducing compression) than is seat design alone. Any factors which influence the seat-symphysis space (including an individual's anatomy, seat design and rider position) can increase the potential for penile hypoxia and erectile dysfunction/perineal numbness. KEYWORDSerectile dysfunction, bicycle seat, bicycle, CT, pudendal artery, digital modelling OBJECTIVETo digitally model (three-dimensional, 3D) the course of the pudendal arteries relative to the bony pelvis in the adult male, and to identify sites of compression with different bicycle riding positions as a potential cause of penile hypoxia and erectile dysfunction. SUBJECTS AND METHODS3D models were made from computed tomography scans of one adult male pelvis (a healthy volunteer) and three bicycle seats. Models were correlated with lateral radiographs of a seated rider to determine potential vascular compression between the bony pelvis and seats at different angles of rider positioning.

Bicycle Riding and the Bedroom: Can Riding a Bicycle Cause Erectile Dysfunction?

“…A limited height difference between the seat and the top of the handlebar prevents putting too much pressure directly on the vulnerable perineum. 23,24 On the other hand, Dettori et al 20 found in their prospective study that if the relative height of the handlebars is parallel with or higher than the saddle, this yields a higher risk of ED (RR, 3.0; 95% CI, 1.1-9.3) compared with the relative handlebar height lower than the saddle. This is attributed to the fact that bicycling in a more upright position forces the buttocks to support more body weight instead of the hands and feet.…”

“…20 Numerous studies have shown that the place of neurovascular compression is between the saddle and pubic symphysis or within the Alcock canal medial to the ischial rami. [21][22][23] Additionally, stretching of the pudendal nerves over the sacrospinal and sacrotuberous ligaments leading to nerve strain could occur by pedaling of the legs. 24 The compression and strain of the neurovascular structures could lead to ED in 3 possible ways.…”

“…23 Least pressure is found in the 90 position and the reclining position. 16,32,35,40 CONCLUSION Although the health benefits to having unrestricted vascular flow to and from the penis and avoidance of long-term nerve compression seem self-evident.…”

A field-based approach for examining bicycle seat design effects on seat pressure and perceived stability

“…These results have been supported recently (Potter et al, 2008) and may be attributed to gender differences in pelvis-saddle interactions and differences in segmental mass distribution. With respect to other seat design studies, females were either not included because of the measurement made (Breda et al, 2005;Gemery et al, 2007;Jeong et al, 2002;Munarriz et al, 2005;Schwarzer et al, 2002), or if they were included as participants, they were grouped into the same analyses as males (Lowe et al, 2004), which negates the ability to generalize results to either gender.…”

Effect of graded bicycle seat pressure on perineal compression: a magnetic resonance imaging analysis: Figure 1

“…There is recent evidence to suggest that riding a bicycle in a seated position may cause substantial compression of neurovascular tissues within the cavernous spaces of the male perineum 1 2. Some clinicians and researchers have argued that perineal compression is the implicit cause of many frequently occurring seat pathologies, which include discomfort, pressure sores, genital numbness and erectile dysfunction 3.…”