Optimizing Development of the Pectoralis Major

Abstract

Jagessar, M. Optimizing development of the pectoralis major. 2009. This article seeks to determine optimum body/hand position and the best exercises for development of the pectoralis major. Gaps in the field of literature are also addressed. Body/hand position, execution, width of grip, trunk inclination, dumbbells and barbells are all variables that affect the prime movers (pectoralis major, anterior deltoid and triceps brachii) of the bench press. Electromyography is a technique used for recording changes in electrical potential of muscle fibres that are associated with their contractions Payton, C. J., Bartlett, R. M. (Eds.) (2008). Electromyographic (EMG) studies are well known for determining muscle activity. Due to the overwhelming contradictory information and various variations of the bench press, EMG studies have been undertaken. The research has shown that the horizontal barbell bench press done with a grip between 165% to 190% biacromial width produces maximum EMG activity in the pectoralis major. The clavicular (upper) head produces maximum activity in the close grip incline barbell bench press. Dumbbells and barbells can be used interchangeably to overcome training plateaus.

Introduction

The bench press is one of the major exercises used for developing upper body strength, particularly in the chest. Be it for sport specific or aesthetic reasons, both elite athletes and fitness enthusiasts spend countless workouts on developing the pectoralis major. Elite powerlifters work on technique for maximizing weight lifted while bodybuilders work on technique for maximizing muscle mass.

The prime movers involved in the bench press are the pectoralis major, anterior deltoid, and the triceps brachii. Each plays an integral part in mobilization of the weight. Variations of the bench press affect involvement of prime movers. Depending on their goals, bench pressers utilize these variations for achieving total development of both the clavicular (upper) and sternocostal (lower) heads of the pectoralis major.

The clavicular head of the pectoralis major has a proximal attachment at the anterior surface of the medial half of the clavicle and distal attachments at the lateral lip of the bicipital groove of the humerus and the anterior lip of the of the deltoid tuberosity. The sternocostal head has a proximal attachment at the lateral aspects of the manubrium and body of the sternum, the upper six costal cartilages and the aponeurosis of external abdominal oblique.

Owing to these several sites of attachments the pectoralis major can be targeted using different variations of the bench press. However one must take into consideration that the primary actions of the clavicular and sternocostal heads are flexion, adduction, and internal rotation of the arm at the shoulder. The sternocostal head has similar primary actions of adduction and internal rotation as the clavicular head except for flexion, in which case it undergoes extension.

Variations of the bench press include the barbell and dumbbell bench press, which can be performed in the incline, horizontal, and decline positions. The barbell bench press can also be performed with a variety of widths of grip ranging from wide to narrow. By changing body and arm position, each of the prime movers can be stimulated to either a greater or lesser extent. Barnett, C., Kippers, V., & Turner, P. (1995) have shown that a close grip produces more activity in the long head of the triceps brachii than a wide grip. Many believe that to achieve overall pectoral development one or more of the variations of the bench press should be performed.

This article seeks to determine which of the variety of lifts will produce optimum development of the pectoralis major.

Bench Press Execution

Algra, B. (1982) illustrates the muscles worked and the starting and finishing positions for the free weight barbell bench press as shown below.

Algra B

As he outlines proper technique, which involves making sure that the bar is balanced, the lifter then positions oneself on the bench with the bar located above the eyes. Note that the bar is still located on the support racks of the bench. Back and buttocks should be firmly placed on the bench pad. Just before lowering the bar to the chest the lifter inhales. When the weight is ready to be lifted the lifter exhales forcefully. Proper control of the weight should be maintained both in the concentric (upward) and eccentric (downward) phases of the lift. Bouncing the bar of the chest can cause damage to the rib cage and sternum and also reduces the workload of the prime movers. This method of “cheating” should be avoided. Bar travel can follow a natural arc. However, to focus on the pectoralis major, a travel close to vertical can be used. Another form of “cheating” involves extreme arching of the back when the lifter raises the buttocks off the bench to utilize momentum for the lift. This must also be avoided to prevent injury to the spinal disc and to effectively work the muscles.

Duffey, M. J., & Challis, J. H. (2007) highlight that because of the importance of neural changes early in a training program, coaches may want to emphasize proper technique rather than reach momentary muscular failure in novice exercisers.

Width of Grip

Width of grip for the barbell bench press can be defined as the distance between the index fingers when the bar is gripped. Proper technique advocates that grip width should be such that when the bar touches the chest the forearms should be perpendicular to the floor. The width of grip for optimum development of the pectoralis major still has yet to be determined.

Clemons, J. M., & Aaron, C. (1997) examined the difference in muscle activity (using an electromyographic, EMG Biopak system) during the concentric phase when width of grip was varied during the flat bench press. Four grip widths of 100%, 130%, 165% and 190% (G1, 2, 3, and 4 respectively) of biacromial width (shoulder width as defined by the distance between acromion processes) were investigated. Mean integrated myoelectric (MiEMG) activity for each muscle was normalized to max volitional isometric contractions (%MVIC). Specific muscles studied were the pectoralis major, anterior deltoids, triceps brachii, and biceps brachii.

The results showed that there were significant differences between G1 and G2 with G4. The G4 grip produced maximum %MVIC for the collective set of prime movers. %MVIC for prime movers in ascending order was the biceps brachii followed by the pectoralis major, anterior deltoid, and the triceps brachii.

There was no significant change in muscle interaction for change in grip width. This is contradicted by other research. However, the results clearly showed that the G4 grip is the best grip since it produced maximum activity in prime movers. The authors suggest that if the G4 grip does not feel comfortable for the lifter, a width between G3 and G4 should be used for good bench press performance.

Clemons, J. M., & Aaron, C. (1997) also outline a method for determining the best lifting grip, which involves lying supine on the floor with the upper arm abducted at 90º and the elbow forming 90º while an Olympic bar is held. This strategy should result in grip widths close to G4.

Note, however that this grip optimizes bench press performance and not specifically the pectoralis major.

Barnett, C., et al. (2005) examined EMG activity for two grip widths of 100% and 200% biacromial width for variations of the bench press exercise. The five muscles investigated were the sternocostal head of the pectoralis major, clavicular head of the pectoralis major, anterior deltoid, long head of the triceps brachii, and the latissimus dorsi. Results showed that the sternocostal head showed most activity during the wide grip horizontal bench press. Also, the clavicular head was more active with narrow hand spacing.

Lehman, G. J. (2005) showed that for the horizontal bench press moving from wide (200% biacromial width) to narrower (100% biacromial width) grip widths increased triceps activity and decreased the sternocostal portion of the pectoralis major.

Trunk Inclination

It has been perceived that by performing the bench press at the incline position the clavicular head is targeted while the horizontal position targets the sternocostal head. Barnett, C., et al. (1995) showed that the clavicular head showed no significant difference in EMG activity from the horizontal to the incline position but was least active during the decline bench press. The sternocostal head showed most activity during the horizontal bench press.

Glass, S. C., & Armstrong, Ty. (1997) EMG results contradict that found by Barnett, C., et al (1995). Their EMG data showed no significant difference for upper pectoral activation between the incline and decline bench press. However, there was significant difference between the incline and decline bench press for the lower sternal portion of the pectoral muscles.

The authors suggest that this difference in results may be due to lower placement of the electrodes in their research. Hence, the decline bench press is suitable for development of the lower sternal portion and not for overall development. The effect of width of grip on their results was not discussed. Width of grip was not standardized for all participants; hence this could have also lead to the difference in results.

Dumbbell vs Barbells

Some trainers advocate the dumbbell bench press for optimum development of the pectoralis major. The reason given is that the dumbbells allow for greater range of motion, hence the muscle can be fully stretched in the eccentric phase and fully contracted in the concentric phase. Other trainers advocate the barbell bench press, for in this lift the participant can perform the exercise with heavier loads when compared to the dumbbells. Heavier loads can be equated to greater strength and muscle mass, which is dependant on the number of repetitions performed with the load.

Welsch, E. A., Bird, M., & Mayhew, J. L. (2005) examined the differences in EMG activity and times of activation for the pectoralis major and anterior deltoid when performing the concentric phase of the barbell bench press, dumbbell bench press, and the dumbbell fly. Relative time of activation of a muscle was defined as the percentage of time the muscle was active when compared with the total time of the concentric phase.

It was found that motor unit activation of both muscles was not significantly different during the three lifts. Also the dumbbell fly had significantly less relative time of activation than the barbell and dumbbell bench presses. It was therefore concluded that the dumbbell fly should be used more as an auxiliary lift whereas dumbbell and barbell bench presses may be used interchangeably in training programs.

Discussion

Proper execution for the bench press is important for targeting specific muscles and prevention of injuries as demonstrated by Algra, B. (1982). In the literature several variables were not factored into the methodologies. Some of these will now be addressed below.

The correct anatomical position for the scapula is back and rotated down. In this position greater stability of the glenohumeral (GH) joint is achieved. During the bench press this position provides a solid platform and keeps the chest out for performing the exercise. This needs to be taken into account when performing EMG studies for the bench press. Lifters who do not practice this position tend to push more with the anterior deltoids and triceps brachii which takes the load of the pectoralis major. This results in underdeveloped pectoral muscles. Also if this position is not standardized, variations in EMG activity of the prime movers in the bench press can be affected.

Another factor that should be considered is abduction of the humerus or the angle of the GH joint. Studies show that a hand spacing of ≥ 2 biacromial width increases shoulder abduction above 75º, whilst hand spacing < 1.5 biacromial width keeps shoulder abduction below 45º as stated by Fees, M., Decker, Snyder-Mackler, L., & Axe, M. J. (1998).

Naturally the GH joint forms these angles. Depending on the width of grip however, these angles can vary during the bench press to make the lift easier. By changing angle, the load can be shifted to specific prime movers during different phases of the lift. Bodybuilders try to keep this angle fixed to emphasize the pectoralis major. Also at a narrow grip, the humerus can be abducted to the 90º angle by control of the side or middle deltoids. Emphasis should be placed on preventing elbow rotation about the median plane, which can lead to fallible results.

The bench press can also be performed with the classic flat lumbar position, the naturally arched or extremely arched positions. The extreme arching as pointed out by Algra, B. (1982) can cause injury to the lower spine. The effect of placing the lower back in the classic or naturally arched position still needs to be investigated. However, this must also be standardized for EMG studies for it is possible that this can also affect results.

Practical Applications

To optimize development of the pectoralis major, the literature has shown the following:

  • The concentric and eccentric phases of the lift should be controlled.
  • The bar should be properly balanced and is not to be bounced off the chest.
  • Back and buttocks should be firmly planted to the bench pad.
  • Extreme arching of the lower lumbar region should be avoided.
  • The best width of grip is between 165% to 190% of biacromial width.
  • The horizontal bench press can be used for development of both heads of the pectorals.
  • The close grip incline barbell bench press can be used for development of the upper clavicular head.
  • Dumbbells and barbells can be used interchangeably to overcome training plateaus.
  • The dumbbell fly should be used as an auxiliary lift.
  • Body position in terms of scapula, elbow and lower back orientation need to be standardized for EMG studies on the bench press.

Further research needs to be undertaken to determine the effect that body position has on the prime movers of the bench press. This can give rise to design parameters which can aid in the development of more effective bench press equipment and technique.

References

Algra, B. (1982). An in-depth analysis of the bench press. National Strength and Conditioning Journal, pp. 6-72.

Barnett, C., V. Kippers, & Turner, P. (1995). Effects of variation on the bench press exercise on the EMG activity of five shoulder muscles. J. Strength Cond. Res., 9, 222-227.

Clemons, J., & Aaron, C. (1997). Effect of grip width on the myoelectric activity of the prime movers in the bench press. J. Strength Cond. Res., 11, 82-87.

Duffey, M. J., & Challis, J. H. (2007). Fatigue Effects on bar kinematics during the bench press. J. Strength Cond. Res., 21(2), 556-560.

Fees, M., T. Decker., L. Snyder-Mackler, & Axe, M. J. (1998). Upper extremity weight-training modifications for the injured athlete: A clinical perspective. Am. J. Sports. Med., 26, 732–742.

Glass, S. C., & Armstrong, T. (1997). Electromyographical activity of the pectorialis muscle during incline and decline bench press. J. Strength Cond. Res., 11, 163–167.

Green, C. M., & Comfort, P. (2007). The affect of grip width on bench press performance and risk of injury. Strength and Conditioning Journal, 5, 10-14.

Lehman, G. J. (2005). The influence of grip width and forearm pronation/supination on upper-body myoelectrical activity during the flat bench press. J. Strength Cond. Res., 19, 587–591.

Payton, C. J., & Bartlett, R. M. (Eds.). (2008). Biomechanical Evaluation of Movement in Sport and Exercise: The British Association of Sport and Exercise Sciences Guidelines. Oxon: Routledge.

Welsh, E. A., Bird, M., & Mayhew, J. L. (2005). Electromyographic activity of the pectoralis major and anterior deltoid muscles during three upper body lifts. J. Strength Cond. Res., 19, 449–452.

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