When you curl, the weight moves out in front of your feet and out of your base of support. Long, lanky arms amplify this problem. When the weights get heavy, your focus shifts away from your biceps to stabilizing your body. However, the old-school training accessory called the "arm blaster" fixes the problem.
Benefits
By resting your triceps on the arm blaster, you can focus on flexing your biceps.
This gives you similar isolation to preacher curls without the added elbow stress at the bottom and loss of tension at the top.
Tip: Resist the urge to let you triceps move off the arm blaster as you curl the weight up.
Good Alternatives: No arm blaster? No problem! If you have long arms, curl with your back against a wall or do seated dumbbell curls on a back-supporting bench.
Since I've started writing for the T-Nation, I've gotten 100's of e-mails asking me varying questions about the rotator cuff and its many somewhat magical qualities. While it may not be as cool as big quads or a great set of guns, a well-developed rotator cuff is sexy in its own, injury-free kind of way.
Unfortunately, your old "what do ya wanna work today?" spur of the moment type training works a whole lot better than anything the Soviet Ministry Of Sport managed to cook up behind the Iron Curtain back in the 50's and 60's. Charles Staley explains why.