By: Barbell Logic Team
When you set your back arch in the bench press, the two points that are trying to move apart are your upper back, where your shoulder blades contact the bench, and your butt, which should be firmly in contact with the bench. At the top, you have vertical and horizontal resistance to help keep your shoulder in place. With sufficient weight on the bar, the vertical downward force of the bar pins your shoulders in place. That pressure is supported by the friction of the bench. Good benches are a bit “stickier” than cheap ones and will help you keep your upper back in place. At the other end of the arch, you do not have the same downward vertical pressure from the bar to help hold you in place. So, while there is friction against the bench, it is less effective than at your upper back. But you can create a vertical resistance to support your arch from the ground with your feet.
Build Your Bench Press Arch
Most of the time physics and anatomy line up nicely in barbell training. Physics tells us that we should move barbells in a straight vertical line so that the force we exert is directed toward work against gravity; this is efficient. Biomechanics also tells us that when a joint rotates to move the barbell through space, any horizontal distance between the bar and the joint creates a moment arm for the muscle operating the joint to overcome, making the load more challenging to resist or move. So, the best way to move barbells for general strength is in straight vertical lines with no unnecessary horizontal displacement from any joint or balance point. For the squat, overhead press, and deadlift this means that we strive for a vertical bar path as part of the correct execution of the exercises.
When anatomy and mechanics agree as they do in these lifts efficient lifting is also safe lifting. Anatomical efficiency means that we turn our bodies into good force transmitters, keeping our spines in rigid anatomical extension, braced with the muscles of our trunks. We also use the skeletal system’s capacity to support compressive forces at the top of the lifts, by keeping our joints extending and stacking the skeletal components that support a load and preventing force traveling from our base of support to the bar from being lost to the bending of a joint. In these main lifts, anatomical stability only supports the mechanical efficiency of the lift.
But not so in the bench press. The bench press is the black sheep of our main lifts; the one that arguably does not fulfill the exercise criteria as well as the other lifts because you get to lie down while doing it. Experience and observation, however, have taught us that the bench press is a valuable addition to the main lifts because it allows us to lift heavy weights training an aspect of the upper body that, in conjunction with the press, rounds out our general, full-body training.
That said, in the bench press anatomy and mechanics are at odds. When you bench press, the lockout position or resting place at the top is directly over the glenohumeral joint (your shoulder joint). In this position, there is no horizontal distance between the load in your hands and your shoulder joint, the bar is held stably in compression. The most efficient way to move the bar down and then back up would be in a straight vertical line, your elbows tracking outward at 90-degrees of shoulder abduction from your body, the bar touching directly along the line of your shoulder joints, and pressing the bar vertically to the lockout position.
Your shoulder anatomy requires something a little bit different. At 90-degrees of shoulder abduction, your upper arm is put in a position to scrape the bony processes of your shoulder blade (the coracoid and acromion processes). This can damage the rotator cuff muscles, causing impingement syndrome and long term damage to the shoulder. So, the most efficient bar path is unavailable to us.
Instead, when you bench press safely, you bring your elbows closer to your body and touch a few inches lower than your shoulder joint—about mid-sternum. This position alleviates any danger of shoulder impingement, making the press safe. But it is also inefficient.
The movement of the bar horizontally down your chest from your shoulder joint creates a moment arm that the muscles of your shoulder must overcome. Thus, anatomy requires that we break our optimal rule of a vertical bar path. But we can still strive for an efficient lift.
The way we do this is with the bench press arch. When you arch your back in the bench press, you are both raising your chest and the touch point that marks the bottom of the movement, shortening the distance vertically. You are also pulling your shoulder horizontally closer to that touch point as well, shortening the amount of horizontal travel away from the shoulder joint that is necessary for the safe execution of the movement. The arch improves the efficiency of an inherently inefficient movement.
But that’s not the whole story because the arch is not easy to maintain at heavy weights during your bench press. When you arch you are concentrically contracting your spinal erectors to extend your spine into that arched position. You are also retracting your shoulder blades to pull them to a flat position against the bench. There is a lot of muscular tension necessary to hold that position. Also, you are supporting a heavy load in your hands requiring stability and control. The net effect of this is that you face the same problem as a bridge builder.
An arched bridge holds its position by resisting the forces of gravity and traffic tendency to push the ends of the arch outward, farther apart from each other. The compressive force on top of the bridge districts down the sides of the arch. If nothing were there holding the arch together at the bottom, then the sides would push apart, and the bridge would collapse. So, too would your bench press arch.
The bridge builder’s answer is an abutment. The bridge abutment resists the outward movement of the bridge’s ends with vertical force from the ground and horizontal force. This holds the arch of the bridge. And you can use the same idea to strengthen the arch of your bench press.
The two points that are trying to move apart are your upper back, where your shoulder blades contact the bench, and your butt, which should be firmly in contact with the bench. At the top, you have vertical and horizontal resistance to help keep your shoulder in place. With sufficient weight on the bar, the vertical downward force of the bar pins your shoulders in place. That pressure is supported by the friction of the bench. Good benches are a bit “stickier” than cheap ones and will help you keep your upper back in place.
At the other end of the arch, you do not have the same downward vertical pressure from the bar to help hold you in place. So, while there is friction against the bench, it is less effective than at your upper back. But you can create a vertical resistance to support your arch from the ground with your feet.
Your feet do not become the end of the arch. If you lift your butt off the bench, your arch now spans from your upper back to your feet. This position is a weak pressing position. Instead, your feet and legs create an abutment, providing horizontal resistance against the tendency for your butt to move away from your shoulders. The most effective resistance is along the same line of the opposing force. If your butt moved farther away from your shoulders, it would do so along the plane of the bench. Parallel to the bench is the optimal direction to resist that movement. Your feet should be actively pushing to create a line of force parallel to the bench pushing you toward the head side of the bench.
When we coach someone in person, this is easy to teach, and you can have a friend help you do this at home. Lie down on the bench without taking the bar out of the rack. Take your regular bench press set up: arch your chest, retract your shoulder blades, knees at 90-degrees, feet flat on the floor. Now, have your friend stand by your head and use their hands to block your shoulders. Their goal is to keep you from sliding upward off the bench. Now, using your legs with your feet flat against the ground, push into their hands. What you should feel is a squeezing and supporting of the arch in your back. Take note of how your legs feel in this position and try to maintain that squeeze.
Now, once you have a little bit of weight on the bar, you can do this on your own. Set your arch before you unrack the bar, then with the weight in your hands push with your legs just like you did before when your friend was blocking your shoulders. Now, HOLD THIS SQUEEZE for the whole set of five. Some lifters are skilled at throwing the bar off their chest, this skill does not start from a relaxed position. Instead, focus on active motionless, continuous stabilization from your feet on the ground through your legs bracing the big stable arch of your back.