Lagging forearm muscles are a common weakness. It’s often difficult to find the time to work in forearms, so most guys forego the forearm training in hopes that all the back and biceps work will stimulate enough growth. Yet, even if you do throw in some forearm work, you may not be doing
it properly. The brachioradialis is the large major muscle on the top of your forearm. To hit it properly, you should be doing reverse-grip curls. But to make sure you place less stress on the brachialis (upper-arm muscle deep to the biceps) and more on the brachioradialis, you want to be sure to do reverse-grip barbell curls with a thumbless grip.
- Alternatives: Reverse-grip dumbbell curls with a thumbless grip, reverse-grip cable curls with a thumbless grip.
WHEN TO GO THUMBLESS: To focus on the brachioradialis, do reverse-grip barbell curls with a thumbless grip (thumbs on the top side of the bar) at the start of your forearm training, immediately after biceps. This better targets the brachioradialis, because the thumbless grip forces you to keep the barbell close to your torso so that your fi ngers remain under the bar. In essence, you do a reverse-grip drag curl, which removes the stress from the brachialis and places it on the brachioradialis. Doing it first in your workout is best, because your grip is strongest, which will allow you to go heavier and place more overload on the brachioradialis.
FORM AND FUNCTION
The brachioradialis starts on the humerus (upper-arm bone) and attaches to the radius (forearm bone). This is the large muscle on the thumb side of the forearm. When it contracts, it flexes the arm at the elbow joint, especially when the arm is pronated (wrist turned in).