ERGOWAVE® study

Performance Based Ergonomics

 

Science & Research - Medicine - Technology & Cycling

 

 

The ERGOWAVE® shape - developed in a research project and in collaboration with the University Hospital of Frankfurt and the Frankfurt University of Applied Sciences. Government funded by the Federal Ministry for Economic Affairs and Energy. For the first time, we were able to calculate the forces occurring deep within the structures of the body and the maximum load between the cyclist and the bike saddle. The final result is the new ERGOWAVE saddle shape for a more ergonomically agressive sitting position on the road and mountain bike, with the top marks among the maximum load in all tests.

The preliminary analysis  

Dr. med. Stefan Staudte conducted a meta-analysis of the pressure tolerances of individual tissue types from existing studies from 1976 to 2012.

The result 

"...at about 15 N/cm² 95% of the maximum tissue tolerance for a medium-term (about 1 - 5h) pressure load is reached."  

The research project

At the same time, we began a research project in 2013 together with the Institute for Materials Science at the University of Applied Sciences in Frankfurt and the Frankfurt University Clinic, and which is funded by the Federal Ministry of Research and Technology to develop biomechanical¬ergonomically optimized bicycle saddles using a virtual human model with in vivo properties. For the first time, we were able to calculate the forces occurring deep within the structures of the body.

The goal 

The maximum load limits in the different fabric tolerances should be less than 15 N/cm².  With regard to the ergonomics of bicycle saddles, this means that they must be optimised and adapted on the basis of biomechanics.

The testing stage

Extensive testing of the previously calculated designs and material combinations were applied as the third pillar of this development project. The SQlab SnaQe-test team, now consisting of nearly 100 international test riders, evaluated the most diverse prototypes in real situations.

In the final step, the remaining designs were checked in the SQlab and other testing areas with pressure and performance measurement systems. 

The final result

The final result is the new ERGOWAVE® saddle shape for a more ergonomically agressive sitting position on the road and mountain bike, with the top marks in all tests. The elevated rear with a slightly rounded shape and the subsequent waveform, which merges into a second small elevated area, gives the pelvis plenty of hold on the backside of the saddle and optimally distributes the pressure all the way into the deep structures of the body. Together with the hollow area in the center, the lower lying saddle nose creates more space for the perineal area.

The pelvis

When sitting normally, the sitbones support the body‘s weight and have the capability to withstand high pressure. This should also be the case when riding a bicycle. With an athletic riding position, the perineal area of men and the lower positioned pubic bone arch of women on the saddle.

The well branched out network of nerves and blood vessels of the perineal area reaches from the anus via the genitals to the upper pubic bone arch. On the sides it reaches past the pubic bones. 

These are capable of carrying a small weight – but a pressure reduction is essential. An even pressure reduction in the perineal area and the pubic bones is achieved through the lowered nose of our SQlab step saddle concept.

The sitting position

When sitting, the sitbones (areas marked in green) serve the purpose of supporting the body’s weight, hence they can endure a high load and pressure. They should also be utilised in this way when riding a bike.

 

In a dynamic riding position the contact point moves from the tip of the sitbones, forwards along the pubic arch to the pubic bone and the central perineal area is used for resting on for both genders. Women however, typically have a lower pubic arch which can result in higher pressure from the saddle nose when riding in a dynamic riding position. The surface area the riders weight is resting on is especially critical in a very dynamic and forward riding position and in such a case the riders weight should not only be supported in the centre but also on the pubic bone.

 

The sitbone and pubic bones both come together from their widest points in a “V” shape. This means the more dynamic the riding position, the narrower the saddle is allowed to, and should be.

Already in 2002 we developed a simple equation which uses the distance of the sitbone tips in dependence of the riding positing to calculate the perfect saddle width. This method has meanwhile been established globally. The method may be interpreted slightly differently from different saddle manufacturers and many leave the adjustment equation away all together, but our basic concept is used in all of these measuring methods.

 

The flexibility of the spine has much less influence on the positioning of the pelvis as often assumed. Spine and pelvis should remain in a natural position relative to each other and not be forced into a certain position, even if the body is very flexible.

 

Especially with the SQlab step saddle it is no longer necessary to tilt the pelvis backwards as the typical pressure zone of the perineal area and pelvis arch no longer pose a problem due to the lowered position of the saddle nose. The energy which is often required to hold the pelvis upright while the upper body taks a dynamic and forward position is no longer required with the SQlab step saddle and can instead be used for pedalling and propelling the bike forward. In addition, there is substantially less load on the spinal discs.