In the propulsion phase, once the hallux touches the ground, it does not move again until the moment of take-off, so when there is a limitation of the plantar flexion of the hallux, the compensation of this is appreciated in other anatomical locations during gait analysis.~For the propulsion phase to be effective, the first metatarsophalangeal joint must be maximally dorsiflexed.~If any structure or movement is altered, the axis varies. In the hallux, the joint surface on which the movement is performed is reduced and therefore affected at the dorsal level, causing a limitation of the main movement of this joint; dorsiflexion in closed kinetic chain, known as functional hallux limitus.~It is for this reason that it is proposed to study the application of plantar supports to favor the movement of dorsiflexion of the first metatarsophalangeal joint and avoid an early establishment of the hallux limitus.
The most important pivot of the sagittal plane is in the first metatarsophalangeal joint, which is usually restricted or blocked as a result of alterations in the rest of the planes or as the main cause of secondary compensations.