Bench Press Flat Smith

Smith machine bench presses increase the size and strength of the upper (clavicular) and lower (sternocostal) heads of the pectoralis major. The triceps and anterior deltoid are also activated in this movement.

Performing bench presses on a Smith machine minimizes 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. The Smith machine latches also provide a level of safety and may allow a lifter to press without a spotter.

The Smith machine bench 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 bar is pressed upward.

The horizontal positioning of this exercise targets both the sternocostal and clavicular heads of the pectoralis major. Therefore, smith machine bench presses are a staple exercise for developing the 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 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.

Incline Smith machine bench press, decline Smith machine bench press, Smith machine close grip bench press, Smith machine wide grip bench press, Smith machine reverse grip bench press, Smith machine reverse and wide grip bench press.

Bench press on a Smith machine requires less activation of the shoulder’s stabilizing muscles, therefore, it is important to strategically alternate between free-weight versions of this exercise (i.e. barbell bench press, dumbbell bench press) and the Smith machine. Performing the free-weight variations of bench press activates these stabilizing muscles (i.e. rotator cuff muscles) and optimizes shoulder and chest strength performance.

Focus on the concentric portion of the contraction, concentrating on “squeezing” as arms are fully extending as you push the bar upward.

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 bench press. Strategically varying your grip width (narrow, standard and wide grip) and hand positioning (supinated grip, pronated grip) can improve overall bench press performance.

Varying your Smith machine bench press angles (e.g. decline bench, incline bench press) can optimize fiber activation of all portions of the pectoralis major.

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.

Lowering the bar too low should be avoided as it results in excessive horizontal shoulder abduction, which can place great stress on the shoulder joint. Ensure that the upper arms do not pass the level of the torso when lowering the bar towards your chest. 1

It is very common to observe an individual arching their back in efforts of lifting the weight with more ease. This technique should only be performed by weightlifting professionals and can compromise the safety of lifters.

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 and 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.