How about an enchantment cantrip?
Lock Tight
enchantment cantrip
Casting Time: 1 action
Range: 50 feet
Components: V, S
Duration: 1 round
You fuse a subject to the floor it stands upon as well as locking its joints momentarily. The target of the spell must make a Strength saving throw. On a failure, the target can not move for one round and it has disadvantage on the next attack it makes.
Thoughts?