The Bench Press is a lift with multiple different variations. This article will examine several of the more common variations and discuss the biomechanical differences and muscle group recruitment.
Traditional Bench Press
First, a look at the traditional bench press. The traditional bench press is done lying on a horizontal plane with both feet, buttocks, shoulders, and head remaining on the floor and bench as the 5 points of contact. The hands are just a few inches wider than shoulder width. The lifter brings the bar down towards their lower chest/upper abdominal region and presses straight vertically, perhaps with the bar path slightly trajecting towards the head. This mode primarily uses the sternal portion (lower 2/3) of the pectoralis major, the anterior deltoid, and the triceps as its agonizing (main) movers. Specifically, the pectoralis major contributes at its highest levels during the initial press off the chest while the triceps begin to play a larger role toward the top half of the movement.
Incline Bench Press
The incline bench press is performed on a bench where the backrest is inclined to anything above parallel with the floor. Typically, the average incline for an incline bench press will be between 30-60 degrees. As the degree of the incline is raised from parallel towards 90 degrees, the clavicular portion (upper 1/3) of the pectoralis major begins to play a larger role than the sternal portion. Additionally, the anterior deltoid will play a larger role as the incline increases as will the lateral deltoid as the incline of the bench crosses over 60 degrees. (note: once the angle of the bench exceeds 65 degrees it could more accurately be described as a shoulder press rather than a bench press.)
Close Grip Bench Press
The third mode of bench press worth mentioning is the close grip bench press. The close grip bench press begins the same as a traditional bench press and is typically done on a flat bench, although it is possible to perform at an incline. However, as opposed to the normal, wider-than-shoulder-width grip, the close grip bench press will involve a hand position inside of shoulder width, though typically with at least 3-4 inches between the hands so as to not aggravate the wrists (this distance may vary on an individual basis). During the close grip bench press, the triceps play a greater role in moving the weight than in both of the aforementioned modes, while the pectoralis major plays a very minor role, relatively speaking.
All three of the types of bench press discussed in this article are great for developing upper body strength and hypertrophy. If a particular muscle group is lagging in strength or if a part of the pressing movement is difficult, try incorporating some variety in your bench press mode.