Dumbbell Hammer Curl

A hammer curl is a resistance exercise, which involves the primary elbow flexors, the brachialis and biceps brachii. This particular biceps exercise emphasizes forearm strength and hypertrophy. The positioning of the hand activates the brachioradialis to a greater extent than in the supinated grip (as in a traditional standing biceps curl). The hammer curl grip is a closed, neutral grip with palms facing inward.

This exercise is performed with dumbbells. The concentric portion of the lift is elbow flexion. The concentric portion involves the lifting of the weight. The eccentric portion is elbow extension, which involves the descent of the weight.

The purpose of hammer curls is to strengthen the biceps from a different angle while emphasizing the activation of the brachialis and brachioradialis. Hammer curls also promote the hypertrophy (increases in size) of the forearms.

Hammer curls strengthen and increase the size of the biceps brachii, brachialis and brachioradialis. Although it is primarily an exercise for aesthetics, hammer curls also serve as an auxiliary exercise that can increase strength involved in other multi-joint exercises.

The brachioradialis, a large superficial elbow flexor that defines the forearm, extends from the elbow joint to the wrist. Performing exercises that activate the brachioradialis helps develop the forearm musculature efficiently over time. Strategically implementing hammer curls in an exercise regimen complements a biceps and forearm exercise routine.

The biceps brachii is located on the front of the arm, originating at the shoulder and inserting in the elbow joint. It consists of two heads, the long head and the short head. The long head tendon helps stabilize the shoulder joint and its origin is located at the tubercle and lip of the glenoid cavity of the scapula (shoulder blade). The short head origin is located at the coracoid process of the scapula (shoulder blade). The long and short head unite as the muscle bellies run down the front of the arm. Both heads merge, sharing insertion into the radial tuberosity of the elbow joint.

The biceps brachii flexes the elbow joint and supinates the forearm. Supination refers to the simultaneous rotation of the wrist and elbow as the palm of your hand faces upward. Although the hammer curl is performed with a semi-pronated grip, placing greater tension on the brachioradialis, the biceps brachii are highly activated in this position.

The brachialis lies underneath the biceps brachii, originating at the front of the lower end of the humerus bone. Its insertion is located at the coronoid process of the ulna at the elbow joint. The brachialis is a primary elbow flexor.

The brachioradialis is a superficial muscle of the lateral forearm. Its origin is located at the lateral supracondylar ridge of the lower end of the humerus bone. It inserts at the base of the styloid process of the radius (where the forearm meets the wrist). The brachioradialis is most activated when semi-pronated during the hammer curl.

The subscapularis works in conjunction with the other three rotator cuff muscles to stabilize the shoulder joint during this exercise.

Prone incline dumbbell hammer curl, simultaneous hammer curl (flexing both arms at the same time as opposed to alternating arms as described above), seated hammer curls, cable hammer curl.

Strategically varying your hammer curl angle, position and repetition scheme (e.g. prone incline dumbbell hammer curls, seated hammer curl, simultaneous hammer curls) can result in optimal muscle activation that increases strength and hypertrophy of the biceps, brachialis and brachioradialis. Incorporating hammer curls in a biceps training regimen complements performance and size gains.

When aiming to increase forearm size and strength, it is important to order your exercises with strategy, training large muscle groups first. Therefore, wrist curls and reverse wrist curls should not be done before a hammer curl or other exercises that target larger muscle groups as they can fatigue forearms muscles and hinder the quality of performance when training larger muscles groups.

When designing your biceps regimen for larger forearms, hammer curls and reverse curls may be placed first in the sequence of biceps exercises to prioritize strength for these two exercises that activate the brachioradialis. At the end of the biceps session, perform wrist curls and reverse wrist curls to isolate the muscles on both sides of the forearm. Be sure to change your exercises, exercise order, intensity and volume every 3-6 weeks to ensure you are acquiring the adaptions from the exercise scheme within that time period. Modifying your training regimen every 3-6 weeks will allow your muscles to make new adaptations throughout the year in accordance with your goals. In the long run, you enhance muscle growth and exercise performance with strategic exercise design.

Focus on the concentric portion of the contraction, concentrating on “squeezing” as the dumbbells are lifted all the way.

Emphasis on eccentric contractions, prolonging the eccentric portion of the contraction, may also be incorporated in a training program focused on increasing strength. This should be implemented accordingly and with adequate muscle recovery as eccentric contractions cause substantial damage to muscle tissue.

It’s important to note that your repetition and set volume will depend on your goals (e.g. strength, hypertrophy, muscular endurance). It is also important to allow adequate recovery days in between biceps training to allow muscles to repair.

Performing exercises that fatigue forearm muscles before reverse curls and/or any exercise that targets large muscle groups. For example, performing reverse wrist curls prior to hammer curls may be detrimental to activating the brachioradialis optimally as the stabilizing wrist extensors are fatigued.

It is very common to observe an individual swinging their torso in efforts of lifting the weight with more ease. This compromises proper technique and biceps contraction. The biceps curl is a single-joint movement. The single-joint involved is the elbow joint. If you find yourself depending on momentum from swinging your torso to lift the weight, you may want to decrease the weight to prevent injury.

Standing on an unstable surface or with an unstable stance can also compromise technique. Your feet are your foundation and should be in a position of stability. If you are looking to maximize the contraction of your biceps, ensure that your feet are shoulder width apart with a slight bend in the knees. Stand on a flat surface. Standing with one foot in front of the other during a standing biceps curl can also compromise balance and decrease the potential for optimal muscle contraction.

If proper technique is not adhered to (e.g. swinging of the torso, dropping the weight quickly instead of controlling the descent on the eccentric portion of the lift), the likelihood of back and/or biceps injury increases.

Although rare, biceps tendon rupture may occur if warm-up is not sufficient and/or if intensity (load) is increased inappropriately.

If proper recovery is not implemented between training days for optimal muscle repair of the biceps, the biceps tendon becomes inflamed. Without proper rest and treatment, the inflammation remains and results in biceps tendonitis.

Impingement syndrome and rotator cuff injuries, in general, are commonly associated with biceps tendonitis/biceps tendinosis. Therefore, it’s best to avoid bicep exercises when addressing impingement syndrome/rotator cuff injury unless advised by a physical therapist.