During pronation of foot, the axes of which two joints become parallel

An impoant function of the foot is propulsion of weight during stance phase . This function is made possible by the MT joint locking and unlocking. During heel strike, the foot needs to be flexible in order to adjust to the surface and the MT joint unlocks to provide this flexibility. Later in the gait cycle, the foot then needs to act as a rigid lever to propel the weight of the body forward which is made possible by MT joint locking. During pronation/eversion of the foot, the axis of the TN and CC joints are parallel to each other, making it easier for them to independently move and unlock the MT joint. The axes cross each other during supination/inversion which locks the MT joint making it difficult to move. Blackwood et al concluded that there is increased forefoot movement when the calcaneus is eveed. This is consistent with the MT joint locking mechanism. Ref - <a href="