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

The Effect of Bike Seat Models on Perineal Pressure During Cycling: Implications for Patients After Lower Genitourinary Reconstructive Surgery

OBJECTIVE

To understand the effect of bicycle saddle shape and size on the pressure transmitted to the perineum, as prolonged perineal pressure and microtrauma amongst avid cyclists may increase the risk for complications following lower genitourinary surgery.

METHODS

We tested five seats (Bontrager, Waterloo, WI) with varying levels of padding and morphology (comfort, fitness, fitness gel, race, and performance) for two different riders. The seats were installed on a Peloton stationary exercise bike (New York City, NY). Force measurements were performed using a 9833E-50 Large F-Socket Sensor (Tekscan, South Boston, MA). We measured total and perineal forces in three conditions at the same resistance: (a) at rest (not pedaling); (b) at 8mph; (c) at 15mph.

RESULTS

Significant differences across the bicycle seats were observed with fitness gel seats providing the lowest perineal pressure. In all measurements, perineal forces were significantly lower at 15mph compared to 8mph (P < .001). When a rider used an oversized seat, less force was exerted compared to the appropriate size at both 8mph (P < .001) and 15mph (P < .001) speeds. Conversely, an undersized seat significantly increased perineal pressures at both 8mph (P = .018) and 15mph (P = .007).

CONCLUSION

Larger seats constructed of more impressionable materials absorb a greater total force and act to distribute the subject's weight thereby delivering less force to the perineum. More perineal pressure is delivered at lower speeds and at rest likely due to the cyclist lifting off the seat during times of strenuous activity.

Erectile function in amateur cyclists

INTRODUCTION

Cycling is a popular means of transport and recreational activity; bicycles are also a source of genitourinary injuries and there is the idea that cycling may have a significant impact on sexual function. The objective of this study was to evaluate the effect of amateur cycling on erectile function.

METHODS

We used a questionnaire comparing amateur cyclists (n = 199) and footballers (n = 43), regarding sexual related comorbidities and hours of practice per week. The cyclists were also characterized in terms of road vs cross-country, breaks during cycling, saddle, and shorts. To evaluate erectile function, the International Index of Erectile Function questionnaire was applied.

RESULTS

there was no difference in International Index of Erectile Function total score between groups. Age and presence of erectile dysfunction associated comorbidity were negative factors in the International Index of Erectile Function score in cyclists but not in the footballers.

CONCLUSIONS

Cycling is usually associated with perineal numbness, but that numbness did not lead to lower International Index of Erectile Function scores. In conclusion amateur cycling has no effect on EF.

Pathophysiology and Grayscale Ultrasonography of Penile Corporal Fibrosis

INTRODUCTION

Penile corporal fibrosis may occur secondary to explantation of an infected penile prosthesis, severe penile trauma, refractory low-flow priapism, Peyronie's disease, or chronic intra-cavernous injection of vasoactive drugs. Other etiologies of corporal fibrosis, presenting primarily with erectile dysfunction, can develop in chronic smokers, hypertensive patients, alcoholics, diabetics, and after radical prostatectomy. Corporal erectile tissue fibrosis is a significant pathophysiologic component of erectile dysfunction; however, current ultrasound-based penile imaging protocols do not directly assess it.

OBJECTIVE

To determine if grayscale ultrasonography (US) is a suitable imaging modality to identify and assess penile corporal erectile tissue fibrosis.

METHODS

A PubMed literature review was performed for studies that detailed ultrasonographic methods and findings of pathologies causing penile corporal fibrosis. Our main outcome measure was the ultrasonographic findings of pathologies causing penile corporal fibrosis.

RESULTS

Grayscale US demonstrates the capability to detect and localize the fibrotic changes of the corpora cavernosa. Ultrasonographic findings capture penile corporal tissue heterogeneity including diffuse, circumscribed, or localized patterns.

CONCLUSION

Overall, grayscale US may be a useful and convenient imaging modality to assess penile corporal fibrosis secondary to explantation of an infected penile prosthesis, priapism, penile trauma, chronic intra-cavernous injection of vasoactive drugs, diabetes, Peyronie's disease, and vascular disease. While limited by the skill and knowledge of the US operator, the combined knowledge of pathophysiology and US may help clinicians identify and manage the underlying etiology of penile corporal fibrosis. Kim J, Drury R, Morenas R et al. Pathophysiology and Grayscale Ultrasonography of Penile Corporal Fibrosis. Sex Med Rev 2022;10:99-107.

Strategies for Reducing the Impact of Cycling on the Perineum in Healthy Males: Systematic Review and Meta-analysis

Introduction

Perineal pressure associated with bicycle riding is the cause of several genitourinary pathologies, most notably Alcock’s syndrome and subsequent perineal numbness. The possible link between cycling-induced perineal numbness and erectile dysfunction makes the development of strategies for perineal protection in bicycle users critical.

Objective

To assess the effectiveness of strategies for reducing the impact of cycling on the perineum in healthy males.

Methods

We have conducted a systematic review and a meta-analysis of studies examining various means of reducing the impact of cycling on the perineum under the PRISMA guidelines.

Results

Out of 2217 screened studies, 22 met our inclusion criteria, and 6 qualified for meta-analysis. The strategies included various designs of saddles, changes in the cycling position, seat shock absorber, shorts with different padding, using the recumbent bike. Using the no-nose saddle and recumbent bike resulted in a significant reduction of perineal pressure and higher penile oxygen pressure compared with a standard saddle. Indirect evidence supports the protective effect of standing on the pedals every few minutes during cycling. More evidence is needed to support—or dismiss—other strategies.

Conclusions

Current evidence supports the use of no-nose saddles as a mean to reduce the negative impact of cycling on the perineum in healthy males at the cost of worse stability and increase of posterior seat pressure. Standing on the pedals every ten minutes might be an effective and potentially widely applicable strategy. The use of a recumbent bike appears to protect the perineum, but several concerns prevent its widespread use.

Electronic supplementary material

The online version of this article (10.1007/s40279-020-01363-z) contains supplementary material, which is available to authorized users.

Effect of Oscillation on Perineal Pressure in Cyclists: Implications for Micro-Trauma

BACKGROUND

Genital numbness and erectile dysfunction in cyclists may result from repeated perineal impacts on the bicycle saddle (micro-trauma) that occur during routine cycling.

AIM

To evaluate the relationship between oscillation forces and perineal pressures among cyclists in a simulated laboratory setting.

METHODS

Participants were fit to a study bicycle to ensure all cyclists had the same torso angle (60 ± 1 degree) and maximum knee angle (150 ± 1 degree). A lever system was used to generate oscillation events of 3 progressively increasing magnitudes. Perineal pressure was continuously measured using a pressure sensor on the bicycle saddle. This process was carried out in each of the following conditions: (1) stationary (not pedaling) with the standard seatpost, (2) pedaling with standard seatpost, (3) stationary with seatpost shock absorber, and (4) pedaling with seatpost shock absorber.

OUTCOMES

We compared perineal pressure changes during oscillation events in the stationary and pedaling states, with and without the seatpost shock absorber.

RESULTS

A total of 39 individuals were recruited (29 men and 10 women). As the amount of oscillation increased from an average of 0.7g (acceleration due to Earth's gravity) to 1.3g, the perineal pressure increased from 10.3% over baseline to 19.4% over baseline. There was a strong linear relationship between the amount of oscillation and increase in pressure (r² = 0.8, P < .001). A seatpost shock absorber decreased the impact of oscillation by 53% in the stationary condition. Men and women absorbed the majority of shock in areas corresponding to pelvic bony landmarks.

CONCLUSION

This study represents one of the first characterizations of cycling-associated perineal micro-trauma in a laboratory setting. We found a strong linear relationship between oscillation magnitude and perineal pressure during cycling, which was mitigated by a seatpost shock absorber. The use of shock absorption in bicycle design may reduce perineal micro-trauma and potentially improve cycling-associated perineal numbness and erectile dysfunction. Sanford T, Gadzinski AJ, Gaither T, et al. Effect of Oscillation on Perineal Pressure in Cyclists: Implications for Micro-Trauma. Sex Med 2018;6:239-247.

Sport and male sexuality

The relationships between sport and sexuality in males are of great social and clinical interest, because of sports and motor activities that highly promote social and sexual relationships. Even if few literature exist, two main questions should be taken into account: whether and how physical exercise and sport positively or negatively influence sexual health and behavior and/or whether and how sexual behavior may affect a sub-sequent sport performance. Physical exercise and sport per se can influence, positively or negatively, the hypothalamic-pituitary-testicular axis function and, consequently, the individual's reproductive and/or sexual health. This depends on individual factors such as genetic and epigenetic ones and on different variables involved in the practice of sport activities (type of sport, intensity and duration of training, doping and drug use and abuse, nutrition, supplements, psychological stress, allostatic load, etc.). If well conducted, motor and sport activities could have beneficial effects on sexual health in males. Among different lifestyle changes, influencing sexual health, regular physical activity is fundamental to antagonize the onset of erectile dysfunction (ED). However, competitive sport can lead both reproductive and/or sexual tract damages and dysfunctions, transient (genital pain, hypoesthesia of the genitalia, hypogonadism, DE, altered sexual drive, etc.) or permanent (hypogonadism, DE, etc.), by acting directly (traumas of the external genitalia, saddle-related disorders in cyclists, etc.) or indirectly (exercise-related hypogonadism, drug abuse, doping, stress, etc.). Sexual activities shortly performed before a sport competition could differently influence sport performance. Due to the few existing data, it is advisable to avoid an absolute pre-competition sexual abstinence.

Idiopathic Partial Thrombosis (IPT) of the Corpus Cavernosum: A Hypothesis-Generating Case Series and Review of the Literature

INTRODUCTION

Idiopathic partial thrombosis (IPT) of the corpus cavernosum is a rare condition. The etiology is not fully understood; however, the presence of an either or not congenital web in these patients may contribute to the development of IPT.

AIM

The aim of this study was to describe 18 new IPT cases and compare these with 38 cases found in the literature.

METHODS

A multicenter retrospective analysis was performed. Descriptive statistics are given.

MAIN OUTCOME MEASURES

The main outcome measures used were clinical presentation, clinical and radiographical diagnostics, treatment and resolution of symptoms.

RESULTS

Patients most frequently presented with perineal swelling (10/18; 56%) and pain (13/18; 72%), unilateral (12/18; 67%) or bilateral (4/18; 22%), and pain during erection (10/18; 72%). Penile curvature, dysuria or fever (each 1/18; 6%) were uncommon presenting symptoms. In our series, magnetic resonance imaging demonstrated a fibrous web in the corpus cavernosum in 100% of cases and was more bilaterally (11/18; 61%) than unilaterally (7/18; 39%) diagnosed. Cycling was found to be a provocative factor for IPT occurrence in patients at risk as 61% (11/18) of patients reported being a frequent cyclist with the episode of IPT occurring immediately after or during cycling activity in 8 out of 18 patients (8/18; 44%). In five centers, 15 patients were treated conservatively, the majority being treated with therapeutic doses of low molecular weight heparin and simultaneous anti-aggregant therapy. In one center, all three patients were treated with a surgical approach. Complete resolution of symptoms was noted in only 50% of cases.

CONCLUSION

IPT is a condition that presents typically with perineal pain and swelling. Cycling is often seen as a provocative factor, while the presence of a fibrous web at the level of the crurocavernosal junction is the underlying disorder allowing for entrapment of blood in the crura. Conservative treatment provides a reasonably good outcome in most cases. For therapy resistant cases, surgery can be considered.

In vivo cell and tissue dynamics underlying zebrafish fin fold regeneration

Background

Zebrafish (Danio rerio) has a remarkable capacity to regenerate many organs and tissues. During larval stages the fin fold allows the possibility of performing long time-lapse imaging making this system very appealing to study the relationships between tissue movements, cell migration and proliferation necessary for the regeneration process.

Results

Through the combined use of transgenic fluorescently-labeled animals and confocal microscopy imaging, we characterized in vivo the complete fin fold regeneration process. We show, for the first time, that there is an increase in the global rate of epidermal growth as a response to tissue loss. Also enhanced significantly is cell proliferation, which upon amputation happens in a broad area concerning the amputation level and not in a blastema-restricted way. This reveals a striking difference with regard to the adult fin regeneration system. Finally, an accumulation of migratory, shape-changing fibroblasts occurs proximally to the wound area, resembling a blastemal-like structure, which may act as a signaling center for the regeneration process to proceed.

Conclusions

These findings provide a novel in vivo description of fundamental mechanisms occurring during the fin fold regeneration process, thereby contributing to a better knowledge of this regenerative system and to reveal variations in the epimorphic regeneration field.

Penile revascularization--contemporary update

Contemporary therapies for erectile dysfunction are generally targeted towards older men and universally engage pharmacological and/or device related treatment options. Penile revascularization, using microvascular arterial bypass surgical techniques, is a non-pharmacological, non-device-related, and reconstructive surgical strategy for men with erectile dysfunction that was first described by Dr Vaclav Michal in 1973. Contemporary penile revascularization attempts to 'cure' pure arteriogenic erectile dysfunction in young men with arterial occlusive pathology in the distal internal pudendal, common penile or proximal cavernosal artery secondary to focal endothelial injury from blunt pelvic, perineal or penile trauma. A microvascular anastomosis is fashioned between the donor inferior epigastric and recipient dorsal penile artery. Increased perfusion pressure is theoretically communicated to the cavernosal artery via perforating branches from the dorsal artery. This article will review the history, indications and pathophysiology of blunt trauma-induced focal arterial occlusive disease in young men with erectile dysfunction, current surgical techniques utilized and results of surgery. Contemporary use of penile revascularization is a logical and wanted therapeutic option to attempt to reverse erectile dysfunction in young men who have sustained blunt pelvic, perineal or penile trauma.

Association between attributes of a cyclist and bicycle seat pressure

INTRODUCTION

Bicycle seat pressure is thought to be the principal risk factor for bicycle seat injuries such as erectile dysfunction; however there is a lack of understanding regarding the characteristics of a cyclist that predict bicycle seat pressure.

AIM

The purpose of this study was to determine if select attributes of a cyclist are associated with seat pressure during stationary bicycling. A secondary purpose was to determine which of the associated attributes were the best predictors of seat pressure and if they were consistent between two different seats.

METHODS

There were two data collection phases to this correlational study in which 40 males between the ages 20 and 50 years volunteered. For the first phase, select attributes of the cyclist (age, weight, flexibility, experience level, and ischial tuberosity width) were measured. The second phase required participants to ride a stationary cycle ergometer while pelvic tilt angles and seat pressures were measured on two different traditional seats.

MAIN OUTCOME MEASURE

The main outcome is the mean and peak bicycle seat interface pressure over the anterior and total seat.

RESULTS

Body weight explained up to 50% of the variance in mean total seat pressure (P=0.001). Regarding peak total pressure, pelvic tilt angle and flexibility explained 43% and 17% of the variance, respectively, for the two seats tested (P=0.01).

CONCLUSION

These results indicate that predictors of mean seat pressure are not the same for peak pressure. Body weight alone accounted for the most variance in mean pressure whereas pelvic tilt and flexibility accounted for the most variance in peak pressure. These variables related to seat pressure may give some guidance to cyclists and clinicians who intend to prevent or alleviate the symptoms associated with bicycle seat injuries that include erectile dysfunction.

Bicycle riding and erectile dysfunction: a review

INTRODUCTION

For many years, reports in the literature have implicated bicycle riding as causing increased risk of erectile dysfunction (ED). Perineal compression during cycling has been associated with the development of sexual complications.

AIM

To review current literature on the rationale for ED from bicycle riding and outcome of bicycle riding on erectile function and to present available research on preventative measures specifically regarding bicycle riding.

METHODS

A systematic comprehensive literature review.

RESULTS

There is a significant relationship between cycling-induced perineal compression leading to vascular, endothelial, and neurogenic dysfunction in men and the development of ED. Research on female bicyclists is very limited but indicates the same impairment as in male bicyclists. Preventative measures including use of a properly fitted bicycle, a riding style with a suitable seat position and an appropriate bicycle seat can help prevent impairment of erectile function.

CONCLUSIONS

There is a need for further research on safe bicycle and bicycle seat design and investigations that address the underlying mechanisms leading to cycling-related sexual dysfunction in both male and female bicyclists.

Effects of workload on seat pressure while cycling with two different saddles

INTRODUCTION

Seat pressure during cycling and its relationship to urological disorders have been discussed extensively in recently published literature. The effects of exercise configuration on seat pressure, however, still have not been fully investigated.

AIM

This study evaluates the effects of two different pedaling workloads and two saddle designs on saddle pressure in 22 (11 men and 11 women) recreational cyclists (bicycling <2 hours per week).

METHODS

Seat pressure was measured in the saddle surface while pedaling at workloads of 150 and 300 W using a plain and a holed saddle model, both without any gel cushion characteristics. Analysis of variance was applied to compare seat pressure between situations.

MAIN OUTCOME MEASURE

Study the importance of bicycle saddle pressure.

RESULTS

Mean seat pressure was not different between men and women. For the plain saddle, the men's average seat pressure increased as the workload increased. Using a holed saddle, the mean pressure increased as the workload increased, regardless of gender.

CONCLUSIONS

The increase of workload increased the seat pressure for the subjects, with the main effects dependent on workload. The use of a holed saddle was not directly related to lesser seat pressure during cycling. Our results support our understanding of a similarity between genders related to mean seat pressure, and suggest that different workload ranges may present different results for seat pressure.

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

The purpose of this study was to investigate the effect of various bicycle seat designs on seat pressure and perceived stability in male and female cyclists using a unique field-based methodology. Thirty participants, comprising male and female cyclists, pedaled a bicycle at 118W over a 350m flat course under three different seat conditions: standard seat, a seat with a partial anterior cutout, and a seat with a complete anterior cutout. The pressure between the bicycle seat and perineum of the cyclist was collected with a remote pressure-sensing mat, and perceived stability was assessed using a continuous visual analogue scale. Anterior seat pressure and stability values for the complete cutout seat were significantly lower (p<0.05; 62-101%) than values for the standard and partial cutout designs. These findings were consistent between males and females. Our results would support the contention that the choice of saddle design should not be dictated by interface pressure alone since optimal anterior seat pressure and perceived seat stability appear to be inversely related.

Does bicycling contribute to erectile dysfunction? Examining the evidence

Bicycling is a popular means of recreation, transport, and fitness training for many people around the world, but questions have been raised about its threat to sexual function. This review summarizes some of the data on whether cycling is or is not an independent risk factor for erectile dysfunction and other sexual complaints. Space limitations will confine our discussion to men, although these problems are also important in women.

Interface forces on the seat during a cycling activity

BACKGROUND

The last several years have seen an increased interest in elucidating the causes of non-traumatic injuries specific to bicyclists. Injuries may include soreness of the pelvis, skin problems in the groin, erectile dysfunction, and impotence. Combined loading at the seat may be contributing factors to these injuries.

METHODS

Vertical and shear loads were collected for 10 subjects cycling at 75 crank revolutions per minute (RPM) in a common fit position. External workload was held constant at 125 watts while force data were collected using a multi-axis load cell integrated under the seat of a standard bicycle. The crank arm angles at which the maximum forces occurred were obtained using a motion analysis system, and regions of rider contact with the seat were visualized with a pressure mapping system.

FINDINGS

Measured vertical loads at the seat were greater than shear loads. Maximum mean vertical loads of 49-52% body weight, rearward shear loads of 11-12% body weight, and lateral shear loads of 4-5% body weight occurred at the seat. Associated timing angles referenced to the pedal position were also measured and averaged at the maximum and minimum loads.

INTERPRETATION

Seat pressure mapping and blood flow have previously been used to study the interaction between bicyclists and their seats. This investigation focused on shear and vertical seat loads that may be contributing factors in injuries at the groin.

ORIGINAL RESEARCH—WOMEN’S SEXUAL HEALTH: Genital Sensation and Sexual Function in Women Bicyclists and Runners: Are Your Feet Safer than Your Seat?

INTRODUCTION

Bicycling is associated with neurological impairment and impotence in men. Similar deficits have not been confirmed in women.

AIM

To evaluate the effects of bicycling on genital sensation and sexual function in women.

METHODS

Healthy, premenopausal, competitive women bicyclists and runners (controls) were compared.

MAIN OUTCOME MEASURES

(1) Genital vibratory thresholds (VTs) were determined using the Medoc Vibratory Sensation Analyzer 3000. (2) Sexual function and sexually related distress were assessed by the Dennerstein Personal Experience Questionnaire (SPEQ) and the Female Sexual Distress Scale (FSDS).

RESULTS

Forty-eight bicyclists and 22 controls were enrolled. The median age was 33 years. The bicyclists were older, had higher body mass indices (BMIs), were more diverse in their sexual orientation, and were more likely to have a current partner. Bicyclists rode an average of 28.3 +/- 19.7 miles/day (range 4-100), 3.8 +/- 1.5 days/week, for an average of 2.1 +/- 1.8 hours/ride. The mean number of years riding was 7.9 +/- 7.1 years (range 0.5-30). Controls ran an average of 4.65 +/- 2.1 miles/day (range 1.5-8) and 5.0 +/- 1.2 days/week. On bivariate analysis, bicyclists had significantly higher VTs than runners, indicating worse neurological function at all sites (P < 0.05). Multivariate analysis found significant correlations between higher VTs and bicycling at the left and right perineum, posterior vagina, left and right labia. Increasing VTs at the clitoris, anterior vagina, and urethra were associated with age. In bicyclists, there were no correlations between VTs and miles biked per week, duration of riding, or BMI. Composite SPEQ scores indicated normal sexual function in all sexually active subjects. Neither group suffered from sexually related distress.

CONCLUSION

There is an association between bicycling and decreased genital sensation in competitive women bicyclists. Negative effects on sexual function and quality of life were not apparent in our young, healthy premenopausal cohort.