Fig. 9From: Establishing a common instantaneous center of rotation for the metatarso-phalangeal and metatarso-sesamoid joints: a theoretical geometric model based on specific morphometricsa, the fibular sesamoid contact point has been placed at the proximal end of its groove. b, it can be seen that there is a change in the CR due to the groove having a different tangent line (B′) from the ridge (B). It has shifted distal in bBack to article page