Hasta means hand. Ut is a particle that indicates intensity. The verb Tan means to stretch, to extend, to lengthen.
This step or posture is performed in the same way as the second step or posture of this Vinyasa.
From Padahastasana inhale and raise the arms and trunk to the sky, bring the shoulders back so that the biceps are close to the ears. Try to extend your entire body, from feet to hands, and arch your head, arms, and trunk a bit backwards. In case of discomfort in the back you can do Urdhva Hastasana, it is the same posture without arching the head, the arms and trunk backwards.
Om Arkaya Namaha: Salutations to He who is fit to be praised