Hammer curls and Reverse Curls?

[Maximum6]

www.exrx.net/WeightExercises/Brachioradialis/DBHammerCurl.html

According to this exercise guide , hammer curls and reverse curls
primarily target the brachioradialis, and using brachialis and biceps as assistent muscles in the movement.

So my question is, why do most trainers say hammer curls would hit the brachialis Yes, it does contract along with the biceps ...
But I just don't understand why they stress this exercise as the exercise to hit the Brachialis?

[masterschamp]

EZ BB Curls also hit it .

[Tim Wescott]

You simply cannot ever totally isolate a single area of a muscle without some assistance frokm other muscles Mike.

Cleans,and Zottman Curls as well as Reverse Cable Curls and Reverse Preachers will hit this area also.