The Foot

The anatomy of the foot 

The foot is composed of 26 bones and can be divided into the forefoot, midfoot and hindfoot. 33 joints provide mobility between the individual limbs. More than 114 tendons and ligaments enable the complex functionality of the foot during upright gait. In addition, a finely fanned out network of nerves and blood vessels runs along the sole and back of the foot.

The foot arch 

The foot has a longitudinal arch and a transverse arch. They are braced by muscles and tendons between the metatarsophalangeal joint of the big toe, the metatarsophalangeal joint of the little toe and the heel and serve to absorb shock when walking. The shape of the arches varies from person to person and is strongly dependent on the foot musculature.



Bracing of the longitudinal arch:

    • plantar aponeurosis
    • ligamentum plantare longum
    • musculus flexor hallucis longus
    • foot's short muscle group

Bracing of the transverse arch:

  • musculus tibialis posterior
  • musculus peronaeus profundus
  • Foot muscles


Together they 'wrap around' the middle foot like a stirrup from the inside and outside and hold the arch up.


Function of the Arch of the Foot

The foot is the first point of contact between you and the earth. With a healthy foot in normal position, the transverse and longitudinal foot arches perform an important cushioning function. The entire body weight must be supported by the foot when walking, and at the same time the peak loads on joints such as the knee, hip and spine must be reduced. To do this, the arches of the feet sink when they make contact with the ground with each step due to the load experienced and rebuild through muscle tension.


Biomechanics and cycling

As the arches of the foot descend, the foot fatigues and direct power transmission to the pedals is reduced. Excessive movement of the foot in the cycling shoe can lead to nerve and vascular constriction, resulting in paresthesias or numbness.

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.