Incline bench press muscles worked

Every role here is for this technique: bench inclined at 30 to 45 degrees, grip about one and a half shoulder widths, bar lowered to the upper chest.

What muscles does the incline bench press work?

The prime movers of the incline bench press are the clavicular part of pectoralis major, the anterior deltoid and triceps brachii. They produce shoulder flexion and horizontal adduction, and elbow extension. The synergists are the sternal part of pectoralis major and coracobrachialis. Ten stabilizers hold joints and segments still, among them serratus anterior, supraspinatus and infraspinatus.

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Joint actions and their prime movers

The joint actions of the incline bench press and the prime movers that produce each
Joint action	Prime movers
Shoulder flexion and horizontal adduction	The clavicular part of pectoralis major and the anterior deltoid
Elbow extension	Triceps brachii

Every muscle by role

A prime mover produces the lift’s main joint action against the load; a synergist assists that action, or adds a secondary action the lift needs; a stabilizer contracts mostly isometrically to hold a joint or a segment still. A role describes what the muscle does in the technique above, not how hard it works or how much it grows.

Prime movers 3

Prime movers in the incline bench press, with what each does
Muscle	What it does here
Pectoralis major, clavicular part	Raising the upper arm forward and across The incline shifts work towards the clavicular part (Lauver et al. 2016).
Anterior deltoid	Shoulder flexion More active as the bench is raised (Barnett et al. 1995).
Triceps brachii	Elbow extension, all three heads

Synergists 2

Synergists in the incline bench press, with what each does
Muscle	What it does here
Pectoralis major, sternal part	Bringing the upper arm across the chest Less active than in the flat press (Barnett et al. 1995).
Coracobrachialis	Shoulder flexion and adduction

Stabilizers 10

Stabilizers in the incline bench press, with what each does
Muscle	What it does here
Serratus anterior	Holding the shoulder blade against the ribs
Supraspinatus	Holding the head of the humerus in its socket
Infraspinatus	Holding the head of the humerus in its socket
Teres minor	Holding the head of the humerus in its socket
Subscapularis	Holding the head of the humerus in its socket
Biceps brachii	Steadying the elbow and the front of the shoulder
Rhomboids	Keeping the shoulder blades pulled together on the bench
Middle trapezius	Keeping the shoulder blades pulled together on the bench
Wrist and finger flexors	Gripping the bar
Wrist and finger extensors	Holding the wrist straight under the bar

Lowering and lifting

What the prime movers of the incline bench press do in each half of a rep
Phase	What the prime movers do
Lowering	The clavicular pectoralis, the anterior deltoid and triceps lengthen under the bar
Pressing	They shorten to drive the bar up and back

Where these prime movers also work

The clavicular part of pectoralis major: prime mover in the flat bench press, push-up and standing overhead press; synergist in the parallel-bar dip.
The anterior deltoid: prime mover in the flat bench press, push-up, parallel-bar dip and standing overhead press; synergist in the dumbbell lateral raise.
Triceps brachii: prime mover in the flat bench press, push-up, parallel-bar dip, standing overhead press and cable triceps pushdown.

Compared with the other horizontal push lifts

Flat bench press: prime movers in both, the clavicular part of pectoralis major, the anterior deltoid and triceps brachii; prime movers only in the flat bench press, the sternal part of pectoralis major.
Push-up: prime movers in both, the clavicular part of pectoralis major, the anterior deltoid and triceps brachii; prime movers only in the push-up, the sternal part of pectoralis major.

Sources

Barnett, Kippers and Turner (1995), J Strength Cond Res 9(4):222
Lauver, Cayot and Scheuermann (2016), Eur J Sport Sci 16(3):309
Neumann, Kinesiology of the Musculoskeletal System, 3rd ed. (2017)

The cited studies that measured muscle activity used electromyography, and a larger signal need not mean more force or more growth (Vigotsky et al. (2018), Front Physiol 8:985). The roles draw on those studies for which muscles a lift involves and how two lifts differ, never to rank one muscle against another.

See these muscles in 3D

Visualiser · Biology Muscles Worked by Exercise 3D Explorer Choose a lift and a real body lights its prime movers, synergists and stabilisers, front and back, with the same muscles in 3D. Visualiser · Biology Muscle Origin, Insertion and Action Explorer Paint a muscle’s origin and insertion on real 3D bones, or click a bone to see what attaches to it.