9 BEST Exercises for Bigger Forearms -  9 BEST Exercises for Bigger Forearms starting on the outside of your forearm you have a group of extensor muscles that help extend your hands outward as well as side-to-side and they're also highly involved in moving your fingers in all different directions as we circle around the inside of the forearm we find the muscles responsible for flexion of the wrist and the fingers which primarily help you curl your hands and fingers inward going a little deeper we find our pronator and our supinator muscles responsible for rotating and turning the hand in and out finally we have one of the larger muscles of the forearm the brachioradialis and this muscle is more involved with flexing at the elbow and moving the entire forearm rather than just the hand this complex group of muscles is what gives us the ability to move our hands and our fingers in all different directions and our forum muscles are involved in almost every...