First Ray Motion
There should be 1/4” dorsiflexory excursion of the 1st metatarsal head with dorsiflexion/inversion ROM of the 1st Ray. Additionally, there should be 1/4” plantarflexory excursion of the 1st metatarsal head with plantarflexion/eversion ROM of the 1st Ray. If the range of motion is restricted in either direction, note semi-rigid. If the range is restricted in both directions, note rigid.

First Ray Position
Establish a plane for the 2nd through 5th metatarsal heads between your index finger and thumb in one hand. Place your index finger and thumb of your contralateral hand onto the 1st metatarsal head. If the fingernail of the index finger holding the 1st met head is pressed into the pad of the index finger of the hand holding 2nd through 5th met heads, the 1st Ray is plantarflexed. If your thumbnail on the 1st presses into the pad of your thumb holding the 2nd through 5th met heads, the 1st Ray is dorsiflexed.

Hallux Dorsiflexion (Open Chain)
Open chain - the hallux is measured relative to the 1st metatarsal shaft.