Someone asked me the other day, “Why do you arch your back so much during the bench press?” I knew the answer, but it is more complicated than many think. I gave the short answer that it helps keep you stable and lift more weight. That’s not a lie, arching does do that, but there are much more details. Those details are what I will review today.
There are a lot of people that bench and there are a lot of people that don’t arch a lot during the bench. Is it a requirement? No, absolutely not. If you understand the principles behind why athletes arch during the press, then you can achieve the same goals without needing as much of an arch as some other athletes. There are a lot of misconceptions when it comes to the arch. First, “you are going to hurt your back.” Will you hurt your back by arching – no, you shouldn’t. Is it the best for your lumbar spine? Absolutely not. You are exaggerating the extension range of motion of the lumbar spine which can bother some people (those who are extension sensitive). If you are extension sensitive, then yes arching during your bench can be problematic and you should avoid it until that sensitivity calms down. For the most part, athletes are not going to end range extension during the bench so it is not as stressful on your joints as most people think. Since you are lying down, there is much less load and compression on your spine (gravity and external load pushing down on your spine are removed). The body can handle the increased ROM since the load is much less (during the bench the gravitational load – gravity + bar/weight – is perpendicular to the spine so no compression). Another point to note is that when you activate your core, tighten, and take your air or whatever you want to call it that is going to engage the dynamic stability system of the core (see my blog about that here). When the dynamic system is engaged, the force is effectively and efficiently transferred through the spine to the shoulders without placing undue stress on the back joints. Second, “that’s cheating; you don’t have to go down as far.” I hate it when people tell me this. Look at my arms; are they parallel with the bench and maybe even under a little bit? You bet. The fact of the matter is that most athletes won’t arch so much that their arms barely have to move. They will still be pressing some serious weight. Third, “you’re not working your chest as much if you arch.” The answer to this question is one of the reasons to arch as I explain below. Those seem to be the most common in my experience. There are a number of other misconceptions, but I’ll just touch on these three today.
Now for the reasons you need to understand about arching (or at least getting everything out of the principle that you can without arching). Let’ start with the answer to the third misconception. As you arch your back, your sternum and your ribs elevate off the bench and tilt towards your head. What does this do at the shoulder joint? Dr. Mike Israetel explains it best, “Arched benching (especially with a retraction of the scapulae) allow a greater use of the lower fibers of the pectoralis major (chest) muscles. Not only is this pushing angle likely safer for the glenohumeral joint of the shoulder, it’s also conducive to the great use of the larger mass of lower fibers (vs. upper fibers) of the pectoralis, which creates a more forceful lift without sacrificing as much safety as a flat pressing position might.” His reference to the glenohumeral joint (shoulder joint) touches on the fact that your shoulder is in a less vulnerable position during the arched bench press. During a flat bench with no arch, the elbows are flared out and the shoulder is being pushed into horizontal abduction. The further down the bar goes, the more stress on the anterior portion of the shoulder joint and all the tissues in that area. With arched benching, the elbows are tucked in slightly and your shoulder is now moving into extension (with some combination of horizontal abduction) which does not render your shoulder in such a vulnerable position for injury. More muscular recruitment with less chance of injury – sign me up!
The rest of the reasons all have to do with creating a more stable platform for the pecs to work. As most know, the lats should be engaged during the bench press. This keeps your shoulders depressed, or “packed” as some call it, which make the pecs more efficient at lifting the weight. Increased efficiency = more weight. Due to where the lats originate and insert, contracting them causes some lumbar extension (so that’s where part of the arch comes from). Now we get into the concept of leg drive. The leg drive is important for keeping the rest of the body stable while the chest is doing the press. Think of the body as a system. If the lower half of the system is unstable, you are using energy controlling that instability instead of transferring the force from your leg drive to your upper extremities. Utilizing the leg drive also helps you drive your shoulders into the bench, adding more assistance to keeping your shoulders as stable as possible (remember more stability = more efficiency = more weight). Sometimes with the leg drive, athletes will actually slide on the bench. This will severely hinder your ability to lift the maximum weight. To avoid sliding, the arch allows more of the force from the leg drive to be driven into the bench rather than parallel too it (which would cause sliding once you overcame friction). See the picture below and take note of the arrows:
There you have it. All the reasons why arching in the bench press is beneficial and explaining some of the misconceptions. If you have any questions please ask in the comment box below! Thanks for reading!
References
Juggernaut. Arching in the bench press: Please STFU. Retrieved 05/26, 2016, from http://www.jtsstrength.com/articles/2015/09/13/arching-in-the-bench-press-please-stfu/