Arnold Press Seated

An Arnold press is a compound resistance exercise, which targets the middle deltoids. This exercise is performed seated with two dumbbells lifted overhead. What differentiates the Arnold press from a traditional overhead dumbbell press is the beginning position with arms positioned in front of the body.

The concentric portion of the lift is elbow extension, shoulder flexion, horizontal shoulder abduction and upward rotation and elevation of the scapula as the dumbbells are pressed upward. The eccentric portion is elbow flexion, shoulder extension, horizontal shoulder adduction and scapular depression/downward rotation as the dumbbells are lowered.

The purpose of the Arnold press is to strengthen the deltoids while also promoting the hypertrophy (increases in size) of the deltoids.

Arnold presses provide a variation in the overhead press that stresses the middle and anterior deltoids, promoting increases in their size and strength. The beginning positioning of this exercise activates the anterior deltoid as the shoulders flex with arms positioned to the front. The middle deltoids become activated as the elbows flare out to the sides.

Activating the middle deltoids can significantly contribute to overall deltoid aesthetics. Performing this exercise in a seated position allows the lifter to further isolate the movement to their upper body.

In addition to serving as an exercise that enhances the aesthetics of the deltoids, Arnold presses also complement athletic performance as the lifter’s overhead and pushing mechanics are optimized.

The deltoid is a thick, multipennate muscle that forms a curtain around the shoulder. It is the primary muscle involved with arm abduction. When developed, the deltoids give the shoulder their round shape. The beginning position, with arms to the front of the body, activates the anterior deltoid as the shoulder flexes. The horizontal shoulder abduction that follows, as the hands rotate, activates the posterior deltoids. When the elbows to flare out to the sides, the middle fibers of the deltoid are activated. The origin of the deltoid is located at the insertion of the trapezius, lateral third of the clavicle and the acromion spine of the scapula. Its insertion is located at the deltoid tuberosity of the humerus.

The triceps brachii, the primary elbow extensor, is located on the back of the upper arm, originating at the shoulder and inserting in the elbow joint. It consists of three heads, the long, medial and lateral head. The medial head lies beneath the long and lateral head. The long head origin is located at the infraglenoid tubercle of the scapula (shoulder blade). The original of the lateral head is located at the posterior shaft of the humerus. The medial head origin is located at the radial groove of the posterior humeral shaft. The long and lateral heads make up the “horseshoe” portion of the triceps. All three heads merge, sharing insertion into the olecranon process of the ulna, located at the elbow joint.

The anconeus is a short, triangular muscle located at the elbow joint. It is the triceps brachii’s synergist with elbow extension. Its origin is located at the lateral epicondyle of the humerus, inserting at the lateral aspect of the olecranon process of the ulna.

The pectoralis major assists the deltoid with shoulder flexion. The pectoralis major also assists with the eccentric portion of the exercise as the shoulders adduct horizontally. The pectoralis major originates at the sternal end the clavicle, sternum and rib cartilage (ribs 1-6) with fibers converging at the insertion located at the greater tubercle of the humerus. The coracobrachialis assists the pectoralis major with shoulder flexion. It is a small muscle originating at the coracoid process of the scapula and inserting half way down the shaft of the humerus. The biceps brachii also assists with shoulder flexion during this exercise. The biceps brachii is a weak shoulder flexor, however.

The trapezius is the most superficial muscle of the posterior thorax. It is a flat and triangular-shaped muscle. The upper fibers of the trapezius elevate the scapula during this exercise. The origin of the trapezius is located at the occipital bone of the posterior skull, the ligamentum nuchae located behind the neck, and at the spines of C7 and all thoracic vertebrae. Its continuous insertion points are located along the acromion and spine of the scapula and lateral third of the clavicle.

The levator scapulae assists the upper fibers of the trapezius with scapular elevation. It is a strap-like muscle deep to the trapezius located at the back and side of the neck. Its origin is located at the transverse processes of C1-C4. Its insertion is located at the medial border of the scapula, superior to the spine.

The serratus anterior is responsible for upward rotation of the scapula during this exercise, aiding in arm abduction. It is a fan-shaped muscle that lies deep to the scapula. It also runs deep to pectoral muscles on the lateral rib cage. When well-defined, you can see the serrated/sawtooth appearance of this muscle below the axilla. Its origin is located at rib 1 through 8 (sometimes 9) by a series of muscle slips. Its insertion is located at the vertebral border of the scapula, covering the entire anterior surface.

The wrist flexors and rotator cuff muscles play an essential role in stabilizing the wrists and shoulder joint, respectively, during this exercise.

Standing Arnold press, overhead dumbbell press, overhead barbell press, cable shoulder press, shoulder press machine.

Strategically incorporating exercises that strengthen the wrists and, in particular, the rotator cuff muscles into your training regimen will promote optimal performance and safety with overhead press exercises.

Focus on the concentric portion of the contraction, concentrating on “squeezing” as dumbbells reach their highest level overhead.

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 triceps and chest training to allow muscles to repair.

Lowering the weight too quickly not only removes the benefits gained from a controlled eccentric contraction, but also increases the risk of injury. It is important that the concentric and eccentric portions of the lift are controlled.

Emphasizing the touching of the dumbbells at the top to signify the completion of a repetition is not necessary. Avoiding this common mistake also ensures that you maintain your elbows underneath your fists.

If proper technique is not adhered to the likelihood of injury increases. If the lifter has a compromised range of motion with the shoulder joint, this exercise can increase the risk of injury and/or exacerbate a previous injury. It is also important that the lifter has proper trunk stability to perform this exercise to prevent back or neck injury.

Arnold presses may place stress on the elbows and wrists. Therefore, if a lifter has a history or wrist and/or elbow injury it is best to consult with a physical therapist before performing this exercise.

If proper technique and recovery are not adhered to, impingement syndrome, rotator cuff injuries, and glenoid labrum tears may result. Therefore, it’s best to avoid overhead press exercises when addressing impingement syndrome/rotator cuff injury unless advised by a physical therapist.