Reverse Curls: Muscles Worked, Benefits, and Proper Form

What muscles do reverse curls work?

The reverse curl primarily targets the brachioradialis, a major forearm muscle responsible for elbow flexion, along with the brachialis muscle, which lies beneath the biceps. While the biceps brachii is still involved, its contribution to elbow flexion is significantly reduced due to the pronated (overhand) grip, shifting the emphasis to the forearm musculature.

Understanding the Reverse Curl

The reverse curl is an elbow flexion exercise performed with a pronated, or overhand, grip on a barbell or dumbbells. Unlike traditional biceps curls where the palms face up (supinated grip), the reverse grip places the hands with palms facing down. This seemingly subtle change in hand position has profound implications for which muscles are maximally recruited, making it a distinct and valuable exercise for comprehensive arm and forearm development.

Primary Muscles Worked

The unique grip of the reverse curl alters the mechanical advantage and leverages specific muscles differently than a standard curl.

• Brachioradialis: This is the star of the reverse curl. The brachioradialis is the largest muscle of the superficial forearm compartment, running along the thumb side of the forearm from the humerus to the radius. It is a powerful elbow flexor, particularly when the forearm is in a pronated or neutral (hammer grip) position. The reverse curl's pronated grip places the brachioradialis in an optimal position for force generation, making it the primary mover.
• Brachialis: Lying deep to the biceps brachii, the brachialis muscle is a pure elbow flexor, attaching to the ulna. Its action is unaffected by forearm rotation, meaning it contributes significantly to elbow flexion regardless of grip. However, because the biceps' contribution is diminished in a reverse curl, the brachialis often takes on a greater relative load, working synergistically with the brachioradialis.
• Biceps Brachii (Long and Short Head): While the biceps is a powerful elbow flexor and supinator, its role in elbow flexion is significantly reduced with a pronated grip. The biceps is most efficient at flexing the elbow when the forearm is supinated (palms up). In a pronated position, the biceps is in a mechanically disadvantaged position, allowing the brachioradialis and brachialis to become the dominant elbow flexors. Nonetheless, the biceps still contributes, albeit less effectively, to the curling motion.

Secondary and Stabilizer Muscles

Beyond the primary movers, several other muscles play crucial roles in stabilizing the movement and assisting the lift.

• Forearm Extensors: Muscles like the extensor carpi radialis longus and brevis, and extensor digitorum, work isometrically to stabilize the wrist and prevent it from flexing during the lift. This prevents the wrist from "breaking" under the weight and ensures a strong, stable base for the curl.
• Wrist Flexors: These muscles, located on the underside of the forearm, act as antagonists to the extensors, providing counter-stabilization to maintain wrist rigidity.
• Shoulder Stabilizers: The deltoids (anterior and medial heads) and rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) work to stabilize the shoulder joint, preventing unwanted movement and ensuring the force is directed through the elbow joint.
• Core Muscles: Especially when performed standing, the rectus abdominis, obliques, and erector spinae engage to maintain a stable torso and prevent compensatory rocking or swaying.

Biomechanical Principles of the Reverse Curl

The efficacy of the reverse curl hinges on specific biomechanical principles:

• Pronated Grip and Muscle Activation: The pronated grip places the biceps brachii in a position where its ability to supinate the forearm is negated, and its mechanical advantage for elbow flexion is reduced. This forces the brachioradialis, which is well-suited for elbow flexion in pronation, and the brachialis, a pure elbow flexor, to take on the majority of the load.
• Leverage and Force Production: The change in grip alters the lever arm dynamics for different muscles. By reducing the biceps' involvement, the exercise effectively isolates and overloads the brachioradialis and brachialis, promoting their growth and strength.
• Focus on Forearm Development: Due to the heavy recruitment of the brachioradialis and the isometric work of the forearm extensors, the reverse curl is an exceptional exercise for building overall forearm mass and strength, particularly in the outer forearm region.

Benefits of Incorporating Reverse Curls

Adding reverse curls to your training regimen offers several distinct advantages:

• Improved Forearm Strength and Grip: Directly targets muscles crucial for grip strength, which has significant carryover to many other lifts (deadlifts, rows, pull-ups) and daily activities.
• Enhanced Elbow Flexor Balance: Develops the brachioradialis and brachialis, ensuring balanced strength across all elbow flexors and potentially reducing the risk of imbalances or injuries.
• Aesthetics: Contributes to thicker, more muscular forearms, which often complete the look of a well-developed arm.
• Injury Prevention: Strengthening the forearm extensors can help prevent common overuse injuries like "golfer's elbow" (medial epicondylitis) and "tennis elbow" (lateral epicondylitis) by promoting muscular balance around the elbow joint.
• Accessory Strength: A stronger brachioradialis and brachialis can indirectly support other arm and back exercises by improving overall pulling power.

Proper Execution and Considerations

To maximize the benefits and minimize the risk of injury, proper form is paramount:

• Controlled Movement: Perform the exercise with a slow, controlled tempo, focusing on the muscle contraction rather than using momentum. Avoid swinging the weight.
• Full Range of Motion: Lower the weight fully until your arms are almost straight, and curl it up as high as possible without shrugging your shoulders.
• Stable Base: Keep your elbows tucked close to your body and avoid letting them flare out. Maintain a rigid torso.
• Grip: Use a pronated grip (palms down) that is shoulder-width apart. An EZ curl bar can sometimes be more comfortable on the wrists than a straight barbell.
• Rep Range: Typically performed for moderate to high repetitions (8-15 reps) to focus on muscle endurance and hypertrophy, but can be adapted for strength with lower reps and heavier weight.
• Variations: Reverse curls can be performed with a barbell, EZ curl bar, or dumbbells (either simultaneously or unilaterally).

Conclusion

The reverse curl is far more than just a "biceps curl with a different grip." It is a specialized, highly effective exercise for targeting the brachioradialis and brachialis, two significant elbow flexors often overshadowed by the biceps. By understanding its unique biomechanics and incorporating it correctly into your routine, you can build impressive forearm strength, enhance grip, and achieve comprehensive, balanced arm development that extends beyond just the biceps.