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

The Effect of Bicycle Saddle Widths on Saddle Pressure in Female Cyclists

Choosing an unsuitable bicycle saddle increases the saddle pressure and discomfort during cycling. Women contract sports injuries more easily than men during cycling owing to their anatomy. To investigate the effect of saddle widths on the saddle pressure in female cyclists. Ten healthy women with an average age of 20.7 ± 1.3 years, height of 162 ± and 5.9 cm, weight of 56.1 ± 7.5 kg, and a sciatic bone width of 15.5 ± 1.4 cm were recruited for this study. The distributions of saddle pressure for four different saddle widths (i.e., narrow, moderate, wide, and self-chosen) were recorded using a saddle pressure mat. Participants were instructed to pedal steadily with a frequency of 90 RPM and a load of 150 watts. Thirty seconds of riding data was randomly retrieved for analysis. The trials were conducted with a counter-balanced design to minimize random errors. One-way repeated measures ANOVA was used to compare the saddle pressure of different saddle widths, and the significance level was set at α = 0.05. When wide saddles were used, the maximum and average pressure on the right surface of the posterior ischium were lower than those with narrow (p = 0.001, p = 0.012) and moderate (p = 0.016, p = 0.019) saddles. The area of pressure on the pubic bone was smaller when using a wide saddle than when using narrow (p = 0.005) and moderate (p = 0.018) saddles, and the area of pressure on the right posterior sciatic bone was larger under the wide saddle than under the narrow (p = 0.017) and moderate (p = 0.036) saddles. The average force was greater with the moderate saddle than with the wide (p = 0.008) and self-chosen (p = 0.025) saddles. Using a saddle with a width that is longer than the width of the cyclist's ischium by 1 cm can effectively improve the distribution of saddle pressure during riding, while providing better comfort.

Could Proprioceptive Stimuli Change Saddle Pressure on Male Cyclists during Different Hand Positions? An Exploratory Study of the Effect of the Equistasi® Device

When pedaling, the excessive pressure on the seat has the potential to produce injuries and this can strongly affect sport performance. Recently, a large effort has been dedicated to the reduction of the pressure occurring at the saddle region. Our work aims to verify the possibility of modifying cyclists’ pedaling posture, and consequently the pressure on the saddle, by applying a proprioceptive stimulus. Equistasi® (Equistasi srl, Milano, Italy) is a wearable device that emits focal mechanical vibrations able to transform the body temperature into mechanical vibratory energy via the embedded nanotechnology. The data acquired through a pressure mapping system (GebioMized®) on 70 cyclists, with and without Equistasi®, were analyzed. Pedaling in three positions was recorded on a spin trainer: with hands on the top, hands on the drop handlebar, and hands on the lever. Average force, contact surface, and average and maximum pressure each in different regions of the saddle were analyzed, as well as integral pressure time and center of pressure. In the comparisons between hands positions, overall pressure and force variables were significantly lower in the drop-handlebar position at the rear saddle (p < 0.03) and higher in hand-on-lever and drop-handlebar positions at the front saddle (p < 0.01). When applying the Equistasi device, the contact surface was significantly larger in all hand positions (p < 0.05), suggesting that focal stimulation of the lumbar proprioceptive system can change cyclists’ posture.

Unique Concerns of the Woman Cyclist

Previously a male-dominated activity, female cyclists now make up nearly half of all cyclists in the United States. Although cycling provides a significant number of health benefits, it is an activity that carries risk of injury, both traumatic and nontraumatic. Sex differences are seen in chest trauma and breast injury, as well as pelvic, given the inherent differences in anatomy. Understanding the relationship of the bicycle to the anatomy of the rider can help mitigate risks for injury.

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.

How does the side of approach impact the force delivered during external chest compression?

BACKGROUND

We investigated the biomechanics of four external chest compression (ECC) approaches involving different sides of approach and hand placement during cardiopulmonary resuscitation (CPR).

METHODS

A total of 60 participants (30 women and 30 men) with CPR certification performed standard continuous 2-min ECC on a Resusci Anne manikin with real-time feedback in four scenarios: rescuer at the manikin's right side with right hand chest contact (RsRc), rescuer at the manikin's right side with left hand chest contact (RsLc), rescuer at the manikin's left side with left hand chest contact (LsLc), and rescuer at the manikin's left side with right hand chest contact (LsRc). Pressure distribution maps of the palm, peak compression pressure, and compression forces were analysed.

RESULTS

The participants' mean age, height, and weight was 24.8 ± 4.8 years, 165.8 ± 8.7 cm, and 62.7 ± 13.5 kg, respectively. Of the participants, 58 and 2 were right- and left-handed, respectively. Significant between-scenario differences were observed in ulnar-side palm pressure. Ulnar-radial pressure differences were higher in the LsLc and RsRc groups than in the LsRc and RsLc groups (0.69 ± 0.62 and 0.73 ± 050 kg/cm² vs. 0.49 ± 0.49 and 0.50 ± 0.59 kg/cm²; respectively; p < 0.05). Ulnar-radial force differences were higher in the LsLc and RsRs groups than in the sLsLc and RsRs groups.

CONCLUSIONS

The higher differences in pressure and force under the LsLc and RsRc approaches may lead to higher risks of potential injury. When performing standard-quality ECC, the LsRc and RsLc approaches, in which compression pressure and force are better distributed, may be more suitable than RsRc or LsLc.

Saddle Height and Cadence Effects on the Physiological, Perceptual, and Affective Responses of Recreational Cyclists

Saddle height influences cycling performance and would be expected to influence cyclists physically, perceptually, and emotionally. We investigated how different saddle positions and cadences might affect cyclists’ torque, heart rate, rate of perceived exertion (RPE), and affective responses (Feeling scale). Nine male recreational cyclists underwent cycling sessions on different days under different conditions with a constant load. On Day 1, the saddle was at the reference position (109% of the distance from the pubic symphysis to the ground), and on Days 2 and 3, the saddle was in the “upward position” (reference + 2.5%) and “downward position” (reference − 2.5%) in random order. Each session lasted 30 minutes and was divided into three cadence-varied 10-minute stages without interruption: (a) freely chosen cadence (FCC), (b) FCC − 20%, and (c) FCC + 20%. We assessed all dependent measures at the end of each 10 minute stage. While there was no significant interaction (Saddle × Cadence) for any of the analyzed variables, torque values were higher at lower cadences in all saddle configurations, and the FCC + 20% cadence was associated with faster heart rate, higher RPE, and lower affect compared with FCC and FCC − 20% in all saddle positions. At all cadences, the saddle at “downward position” generated a higher RPE compared with “reference position” and “upward position.” The affective response was lower in the “downward position” compared with the “reference position.” Thus, while cyclists perceived the downward (versus reference) saddle position as greater exercise effort, they also associated it with unpleasant affect.

The effect of saddle nose width and cutout on saddle pressure distribution and perceived discomfort in women during ergometer cycling

The objectives were 1) to design and produce two novel unpadded bicycle saddles with a wide/medium width and partial nose cutout; 2) to investigate the responses on pressure distribution and perceived discomfort in female cyclists. For comparison, a standard saddle was also tested. Nineteen female cyclists pedaled on an ergometer cycle for 20 min with each saddle in a counterbalanced order. A pressure mat measured saddle interface pressure. Discomfort ratings were collected using a visual analogue scale. Total mean saddle pressure remained similar across saddles. The wide saddle increased anterior and decreased posterior mean saddle pressure as compared with the standard (p < .002) and the medium saddle (p < .001). Significantly increased ischial tuberosity discomfort was found for the novel saddles (p < .001), while crotch discomfort was not significantly different between saddles. The medium width saddle appeared to be the best compromise since increased crotch discomfort was avoided and saddle pressures were redistributed. Such design may be suggested as an alternative to traditional saddles for women reporting discomfort in the perineal region.

Applying riding-posture optimization on bicycle frame design

Customization design is a trend for developing a bicycle in recent years. Thus, the comfort of riding a bike is an important factor that should be paid much attention to while developing a bicycle. From the viewpoint of ergonomics, the concept of "fitting object to the human body" is designed into the bicycle frame in this study. Firstly, the important feature points of riding posture were automatically detected by the image processing method. In the measurement process, the best riding posture was identified experimentally, thus the positions of feature points and joint angles of human body were obtained. Afterwards, according to the measurement data, three key points: the handlebar, the saddle and the crank center, were identified and applied to the frame design of various bicycle types. Lastly, this study further proposed a frame size table for common bicycle types, which is helpful for the designer to design a bicycle.

Biomechanical Comparison of Shorts With Different Pads: An Insight into the Perineum Protection Issue

An intensive use of the bicycle may increase the risk of erectile dysfunction and the compression of the perineal area has been showed to be a major mechanism leading to sexual alterations compromising the quality of life. Manufacturers claim that pads contribute to increase cyclists perineal protection ensuring a high level of comfort. To investigate the influence of various cycling pads with regard to perineal protection and level of comfort. Nine club road cyclists rode 20 min on a drum simulator, located at the Nutrition and Exercise Physiology Laboratory, at a constant speed and gear ratio wearing the shorts with 3 cycling pads of different design and thickness: basic (BAS), intermediate (INT), and endurance (END). Kinematics and pressure data were recorded at min 5, 15, and 20 of the test using a motion capture system and a pressure sensor mat. The variables of interest were: 3-dimensional pelvis excursions, peak pressure, mean pressure, and vertical force. The comfort level was assessed with a ranking order based on the subjects' perception after the 20-min trials and measuring the vertical ground reaction force under the anterior wheel as well as the length of the center of pressure (COP) trajectory on the saddle. Results showed that the vertical force and the average value of mean pressure on the saddle significantly decreased during the 20-min period of testing for BAS and END. Mean peak pressure on the corresponding perineal cyclist area significantly increased only for BAS during the 20-min period. Interestingly objective comfort indexes measured did not match cyclists subjective comfort evaluation. The lower capacity of BAS to reduce the peak pressure on the corresponding perineal area after 20 min of testing, together with its positive comfort evaluation, suggest that a balance between protection and perceived comfort should be taken into account in the choice of the pad. Hence, the quantitative approach of objective comfort indexes introduced in this study could be helpful for manufacturers in the development of their protective pads.

Optimal protruding node length of bicycle seats determined using cycling postures and subjective ratings

This study examined body posture, subjective discomfort, and stability, requiring the participants to ride a stationary bicycle for 20 min (cadence: 60 rpm; workrate: 120 W), using various combinations of two handle heights and five seat-protruding node lengths (PNLs). The results indicated that bicycle handle height significantly influenced body posture, and that seat PNL caused differences in the riders' subjective discomfort and stability scores. The various PNLs affected only the trunk angle (approximately 6°), but had significantly positive (r = 0.994, p < .005) and negative (r = -0.914, p < .05) correlations with the subjective discomfort rating for perineum and ischial tuberosity, respectively. When the participants were seated at PNL = 0 or 3 cm, cycling using dropped handles was less stable compared with using straight handles; however, the handle height did not affect the cycling stability when the PNL was ≥ 6 cm. The results suggest that a 6-cm PNL is the optimal reference for bicycle seat designs.

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.

A subjective framework for seat comfort based on a heuristic multi criteria decision making technique and anthropometry

Consumer expectations for automobile seat comfort continue to rise. With this said, it is evident that the current automobile seat comfort development process, which is only sporadically successful, needs to change. In this context, there has been growing recognition of the need for establishing theoretical and methodological automobile seat comfort. On the other hand, seat producer need to know the costumer's required comfort to produce based on their interests. The current research methodologies apply qualitative approaches due to anthropometric specifications. The most significant weakness of these approaches is the inexact extracted inferences. Despite the qualitative nature of the consumer's preferences there are some methods to transform the qualitative parameters into numerical value which could help seat producer to improve or enhance their products. Nonetheless this approach would help the automobile manufacturer to provide their seats from the best producer regarding to the consumers idea. In this paper, a heuristic multi criteria decision making technique is applied to make consumers preferences in the numeric value. This Technique is combination of Analytical Hierarchy Procedure (AHP), Entropy method, and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). A case study is conducted to illustrate the applicability and the effectiveness of the proposed heuristic approach.

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.