Hammer Curl Benefits and Muscles Worked

The hammer curl is a popular biceps exercise performed with the wrist in a neutral position. Unlike a standard bicep curl, this exercise targets more of the bicep peak and forearms. It requires minimal equipment to perform and is rather simple to learn.

The hammer curl is an effective exercise for increasing the size and strength of the upper arms. This article covers the top of hammer curl benefits and muscles worked. 

Hammer Curl Benefits

1. Increases bicep muscle size and strength
2. Increases forearm size and grip strength
3. Places less strain on the wrist
4. Can be performed seated or standing
5. Helps fix muscular imbalances

How To Do HAMMER CURLS For BIGGER BICEPS (THESE WORK!)

Here are the top five hammer curl benefits:

Increases bicep muscle size and strength

The hammer curl is primarily used to increase the size and strength of the biceps, which is one of the main muscle groups that make up the upper arms. Since this exercise is performed with a neutral grip, it primarily targets the biceps brachii long head.

This muscle is positioned on the outside of the upper arm and forms the bicep peak. When flexed, the peak contributes to the overall height of the biceps muscle. Hammer curls targets the long head of the bicep, which offers the best arm aesthetics when developed.

Even though the biceps are more of a “show” muscle, they are still important for various movements and are active in any motion that involves elbow flexion.

Increases forearm size and grip strength

Grip strength is crucial for numerous exercises, such as deadlifts, rows and pull-ups.

A traditional biceps curl also works the forearms; however, a hammer curl engages more of the brachioradialis and brachialis. The brachioradialis is a superficial forearm muscle, whereas the brachialis is located directly under the biceps brachii. As the brachialis muscle grows, the biceps brachii look even bigger.

Places less strain on the wrist

Compared to other bicep exercises where the wrist is supinated (palms facing up) or pronated (palms facing down), the hammer curl uses a neutral grip, which places less strain on the wrist.

It’s important to note that in addition to elbow flexion, the biceps are also responsible for wrist supination. Since the hammer curl does not involve supination, it’s a good idea to perform some exercises that involve that.

Performing hammer curls will also allow for biceps work without placing additional stress on the wrists and elbows. Additionally, varying bicep movements can help avoid risk of golfer’s or tennis elbow.

Can be performed seated or standing

This exercise requires minimal equipment or space and can be performed seated or standing. For the most effective means of isolating the movement, seated hammer curls are recommended. Consider doing standing hammer curls to lift as much weight as possible. 

Helps fix muscular imbalances

Due to the neutral wrist position, the hammer curl is considered a unilateral exercise, meaning each arm moves independently. The only hammer curl variation where this is not the case is a rope cable hammer curl.

Traditionally, this exercise is performed with dumbbells, making it unilateral. Some people do alternating or single-arm hammer curls where they focus on one arm at a time. The hammer curl is also helpful in correcting muscular imbalances.

Hammer Curl Muscles Worked

• Biceps Brachii
• Brachialis
• Brachioradialis
• Forearm flexors

Here are the primary hammer curl muscles worked:

Biceps Brachii

The biceps brachii, commonly known as the biceps, is a two-headed muscle on the upper arm. Its actions include elbow flexion, shoulder flexion, and wrist supination. The short head originates from the coracoid process of the scapula and attaches to the radial tuberosity. The long head originates from the supraglenoid tubercle of the scapula and attaches to the radial tuberosity.

The biceps short head is located on the medial side of the arm, which means it’s closer to the body. It helps add width to the upper arm. In comparison, the long head is located on the lateral side of the arm and helps add height to the upper arm, also known as the bicep peak.

Although one head of the biceps brachii can’t be isolated, the elbow position can be manipulated to emphasize one more than the other. For example, the long head is targeted better when the elbows are at the sides of the body. In comparison, the short head is engaged more when the elbows are slightly in front of the body.

Brachialis

The brachialis muscle is located underneath the biceps brachii muscle. It originates from the medial and lateral sides of the humerus and attaches to the ulnar tuberosity. This muscle works with the biceps brachii to flex the elbow.

Unlike the biceps brachii, it does not perform any other action. Although the brachialis is a deep muscle, it still contributes to overall upper arm mass because it pushes the biceps brachii upward as it grows.

Brachioradialis

The brachioradialis is a superficial muscle most prominent when the forearm is half pronated with the elbow flexing, which is exactly the same motion as a hammer curl.  This muscle runs from the humerus to the distal end of the radius.

Although it’s in a similar position as the wrist extensors, its primary action is elbow flexion. The brachioradialis is one of the biggest muscles in the forearm. So if you want to increase the size and strength of your forearms, hammer curls are a great movement to accomplish that by targeting the brachioradialis.

Forearm Flexors

The last muscle group that hammer curls work are the forearm flexors, which include: flexor carpi ulnaris, palmaris longus, flexor carpi radialis, pronator teres, flexor digitorum superficialis, flexor pollicis longus, pronator quadratus, and flexor digitorum profundus. The forearm flexors are all located in the anterior compartment of the forearm.

They all contribute to wrist flexion, finger flexion, and forearm pronation. This muscle group is important for every movement that requires a strong grip. They are especially active during a hammer curl because you’re gripping the dumbbell with the forearm in a half-pronated position.

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About Heather Jacques

Heather Jacques is a former collegiate athlete that graduated from Grand Valley State University with a Bachelor of Science in Athletic Training. Along with writing content for Lift Vault, Heather works for one of the fastest growing sports nutrition companies, Axe & Sledge Supplements, as their product specialist. Heather is an avid lifter, snowboarder, and outdoor enthusiast. She was born in Colorado, raised in northern Michigan, and currently resides in Pennsylvania. Heather's primary goal is to help others achieve their health and fitness goals through education, motivation, and inspiration.