Contortion

You attempt to make a limb of a creature within range to twist in a unnatural way. choose a creature within range, the target makes a constitution saving throw or take 1D6 force damage. other effects take place depending on what limb you choose. Arm: they get -2 to their next attack role or strength saving throw until your next turn. Leg: they get a -5 to their movement speed until your next turn.

the spell's damage increases when you reach 5th level (2D6), 11th level (3D6), and 17th level (4D6).