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.

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.

Inclusion Criteria:

• Interest in participating and completing the phases of the study and signing of the informed consent by the parents. Patients who do not meet any exclusion criteria will be included.

Exclusion Criteria:

• The exclusion criteria will be refusal to sign the informed consent, hypermobility, neurological diseases, previous traumatic history affecting one or both lower extremities, rheumatic pathologies, as well as patients with an angular value of the first metatarsophalangeal joint less than 10º and ankle flexion less than 10º with the knee in extension.