Aaron Small, Personal Trainer: To work your triceps muscles I like to use the cable crossover machine as well. To do this exercise, grab hold of the horseshoe bar, bring it down to waist level,You want to create a stance to protect your back. You need to bend your knees, kind of shoot your rear out a little bit, keep your elbows at you side,What you will do is extend the weight down. Now what you want ot do is start with your forearms about parallel with the ground.When you're ready to start the exercise gently bring the weight down, extending at your elbows. You want to make sure your elbows stay at your side. And do not move.This would be incorrect. Where my elbows are not stay by my side. You're just cheating. When you are done with this exercise smoothly, bring the bar back up to the top.