Back Deltoids Machine Mainly Exercise uper body(deltoid),Freeweight PA was created to develop strength, power and speed, so much so that internationally renowned athletes choose it for their daily training. Freeweight High Performance is unequaled on the market and represents the best joint biomechanics to train at maximum levels in safety and with comfort.;The trajectory of the Free Weight machine is biomechanically correct. You will target every muscle group in a perfect manner.