Chest Press

A machine chest press is a resistance exercise, which involves the primary horizontal shoulder adductor, the pectoralis major. It is a variation of the bench press. This exercise is performed at a chest press machine. Machine chest press machines can be loaded by weight plates or by a weight stack with a pulley system.

The concentric portion of the lift is horizontal shoulder adduction and elbow extension. The concentric portion involves the lifting of the weight. The eccentric portion is horizontal shoulder abduction and elbow flexion, which involves the descent of the weight.

The purpose of the machine chest press is to strengthen the pectoralis major while promoting hypertrophy (increases in size) of this muscle.

Machine chest presses increase the size and strength of the upper (clavicular) and lower (sternocostal) heads of the pectoralis major.

Machine chest presses minimize the activation of stabilizing muscles (i.e. rotator cuff muscles) as the range of motion is controlled. This may allow the lifter to lift heavier weight compared to what they can lift with a free-weight barbell or dumbbells.

Performing machine chest presses allow the lifter to execute a bench press movement from a vertical position and seated. The pulley system of the machine also provides a uniform resistance throughout the entire range of motion.

Machine chest presses cater to beginners acquiring bench press mechanics and strength. They are also ideal for experienced lifters seeking a variation in bench press execution that does not require a spotter.

The triceps and anterior deltoid are also activated in this movement.

The machine chest press serves not only as an exercise to improve aesthetics of the pectoral muscle, but also as a valuable training tool for sports that entail pushing and throwing.

The pectoralis major is a large, fan-shaped muscle that spans across the chest, forming the front portion of the axillary fold (arm pit). It is divided into two parts: clavicular and sternal. Its origin is located at the sternal end of the clavicle, the sternum, rib cartilage (ribs 1-6 [or 7]), and the aponeurosis of the external oblique. The fibers of the pectoralis major converge at the point of insertion located at the greater tubercle of the humerus. The pectoralis major aids in pushing movements as the shoulder adducts the arm against resistance. The shoulder horizontally adducts as the weight is pressed forward.

The vertical positioning of this exercise targets both the sternocostal and clavicular heads of the pectoralis major. Machine chest presses are a complementary exercise for developing the entire chest.

The triceps brachii 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 triceps brachii extend the elbow joint. The long head assists in arm adduction as with the bench press pushing motion.

The deltoid is a thick, multipennate muscle that forms a curtain around the shoulder. It is the primary muscle involved with arm abduction and the anterior fibers are a primary shoulder flexor. The anterior deltoid is a primary synergist of the pectoralis. When developed, the deltoids give the shoulder their round shape. 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 anconeus is a short, triangular muscle located at the elbow joint. Its origin is located at the lateral epicondyle of the humerus, inserting at the lateral aspect of the olecranon process of the ulna.

Like the anterior fibers of the deltoid, the coracobrachialis is a synergist of the pectoralis major with horizontal shoulder adduction. It is a small muscle originating at the coracoid process of the scapula and inserting half way down the shaft of the humerus.

The wrist flexors and extensors stabilize the wrists, the abdominals stabilize the torso and the rotator cuff muscles stabilize the shoulder girdle.

Barbell bench press, dumbbell bench press.

To minimize negative stress on your shoulder joint, do not allow the upper arms to pass behind the torso.

For optimal results, strategically incorporate free-weight bench presses (e.g. barbell bench press, dumbbell bench press) in your chest training regimen. Activating pectoralis major fibers from a variety of angles maximizes strength and hypertrophy gains. Performing the free-weight variations of bench press also activates stabilizing muscles (i.e. rotator cuff muscles), optimizing shoulder and chest strength performance.

Focus on the concentric portion of the contraction, concentrating on “squeezing” as elbows are fully extending as you push the weight forward.

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.

In order to improve pushing performance through “sticking points”, partial repetition ranges may be implemented to improve full range of motion of the machine chest press.

It is 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 chest and triceps training to allow muscles to repair.

On the eccentric phase, bringing your shoulders and upper arms behind your torso should be avoided as it results in excessive horizontal shoulder abduction. This can place great stress on the shoulder joint. Ensure that the upper arms do not go behind the torso when lowering the weight. 1

It is very common to observe an individual arching their back in efforts of lifting the weight with more ease. This can increase the risk of injury.

1. Reinold MM, Gill TJ, Wilk KE et al. (2010). Current concepts in the evaluation and treatment of the shoulder in overhead throwing athletes, Part 2. Sports Health. 2(2):101-115.

If proper technique is not adhered to (e.g. arching of the back, lowering the upper arms past the level of the torso, dropping the weight quickly instead of controlling the descent on the eccentric portion of the lift), the likelihood of injury increases.

If proper technique and recovery are not adhered to, impingement syndrome, rotator cuff injuries, biceps tendonitis/biceps tendinosis, pectoralis major tears and/or glenoid labrum tears may result. It is best to avoid bench press exercises when addressing impingement syndrome/rotator cuff injury unless advised by a physical therapist.