I have been doing research this week. A colleague, Brenda Adams, emailed me and asked if I had any references on what muscle was used during the bench press.
I know what muscle works, but I did not know if what I knew was right, so I hit the books.
I found the answer and some information on grip and bench press, plus which is better – machines or free weights.
What Muscles Are Working during Different Bench Presses?
What They Looked at
This experiment investigated the effects of varying bench inclination and hand spacing on the EMG activity of five muscles acting at the shoulder joint.
What They Did
Six male weight trainers performed bench presses under four trunk inclination conditions and two hand spacing at 80% of their predetermined maximum.
What They Found
- The sternocostal head of the pectoralis major was more active during the press from a horizontal bench than from a decline bench.
- The clavicular head of the pectoralis major was no more active during the incline bench press than during the horizontal one, but it was less active during the decline bench press.
- The clavicular head of the pectoralis major was more active with a narrow hand spacing.
- Anterior deltoid activity tended to increase as trunk inclination increased.
- The long head of the triceps brachii was more active during the decline and flat bench presses than the other two conditions and was also more functional with a narrow hand spacing.
- Latissimus dorsi exhibited low activity in all conditions.
If the research above interested you, make sure to get the free seminar that I did on exercise and shoulder injuries.
What Muscles are Working During Different Bench Press Grips?
What They Looked at
They examined muscle activity during the isometric hold of 5 different bench press exercises. They looked at grip width (narrow, mid, and wide) and supination/pronation to see how these factors influenced muscles in the flat bench press.
What they Found
- A supinated grip (palm up) increased activity for the biceps brachii and the clavicular portion of the pectoralis major.
- Moving from comprehensive to narrower grip widths increased triceps activity and decreased the sternoclavicular portion of the pectoralis major.
- If the grip was supinated, moving to a narrower position did not result in decreased muscle activity of the sternoclavicular portion of the pectoralis major.
- Increased triceps brachii activity when moving to a narrower grip width was not influenced by the level of supination.
What They Recommend
Considering the small changes that occur during changes in grip width, the choice of grip position should be determined by the positions athletes adopt during their sport. Sport specificity should supersede attempts to train specific muscle groups.
Take Home Message
As you know from the blog, I look at things from an injury point of view. I know this information will help me change forces in the exercises depending on a person’s injury. For someone with an AC joint sprain, I can switch from a pronated grip to a supinated grip when doing the bench press and see if this modification allows them to keep doing the exercise while they recover from their injury.
What is Better, a Free Weight or Machine Bench Press?
What They Looked at
They looked at the anterior deltoid, medial deltoid, and pectoralis major muscle activation during a Smith machine and free weight bench press at lower and higher intensities.
Results indicated greater activation of the medial deltoid on the free weight bench press than on the Smith machine bench press. There was no difference in muscle activation for anterior deltoris and pectoralis major between the exercises.
They also recommended that the free weight may be a better exercise because it challenges the scapular stabilizers of the shoulder. At the same time, the Smith machine bench press may have a role in injury recovery and teaching novice weight trainers.
I hope you enjoyed the blog post. Please let me know what you think below in the comments area.
Rick Kaselj, MS
Schick EE, Coburn JW, Brown LE, Judelson DA, Khamoui AV, Tran TT, Uribe BP. (2010). A comparison of muscle activation between a Smith machine and free weight bench press. J Strength Cond Res. 2010 Mar;24(3):779-84.
Barnett C. (1995). Effects of bench press exercise variations on the EMG activity of five shoulder muscles. 1995 Nov;9(4):10-14. (Yes, it is an oldie but a goodie. Let me know if you have something more recent.)
Lehman GJ. (2005). The influence of grip width and forearm pronation/supination on upper-body myoelectric activity during the flat bench press. J Strength Cond Res. 2005 Aug;19(3):587-91.