Which muscles are working and when?
In the bench press, there are 3 main movements happening at the shoulder:
Pec major (lower fibres)
Anterior delt, Pec major (upper fibres)
Now let’s break up muscle activity during the decent (lowering phase or the eccentric) and ascent (pressing phase or concentric) in the bench and determine what that tells us when we’re working with decent weights (70% of our max).
Simplified from Krol & Golas, 2017
As we lower the bar, pec has the highest activity and the delts + triceps are relatively silent. On the way up, the opposite happens, with anterior delt and triceps ramping up with the pec only increasing slightly. If you’re a Fast and Furious fan, think of the pecs as an engine that’s constantly running. The delts and triceps are your nitrous. If you are not a Fast and Furious fan (shame on you!), this means is that our pecs serve as the base for the delts and triceps.
So there are four scenarios that we can attribute to misses or shoulder pain on the bench.
Underloaded/weak pecs leading to overload elsewhere
If there is a failure or dysfunction at the pecs, there is a potential for overloading and injuring the shoulders due to the increased demand at the anterior delt and rotator cuff muscles.
Overloading underloaded/weak delts
You could have strong pecs, but due to the a massive amount of leverage that the delts and must overcome in the bottom of the bench press (the bar is the most furthest away from the shoulders at this point) a deficiency here could also result in injury to the cuff and/or biceps tendon and misses off the chest.
Overloading underloaded/weak triceps
The triceps could be deficient. The long head attaches into the shoulder and potentially can contribute to shoulder stability. Strong triceps are required to bust through the sticking point just above your chest during the bench.
Overloading an underloaded/weak rotator cuff
All your movers could be strong, but your stabilisers, the rotator cuff could be lacking. The “rotator cuff” are a set of 4 muscles that sit directly on the shoulder blade and help stabilise the arm. Think about your cuff muscles as magnets. When you move your arm, the bigger muscles also apply a small glide to the shoulder joint (we are talking micromillimetres here). In the case of the bench, pec and delt slide the shoulder forward, which mean the rotator cuff muscles at the back (infraspinatus, teres, and to an extent supraspinatus) must be recruited to recentre the humeral head to minimise compression/ irritation inside the shoulder.
In day-to-day movement, our shoulders are free to rotate to allow the cuff to work at their optimal length. However, because our shoulder blades need to be locked for the bench press (we will cover this in #scapsdownandback), the posterior cuff must work a lot harder. We therefore need these to be strong to prevent overload on the cuff tendons themselves and to minimise impingement from the humeral head gliding.
To determine if it is a rotator cuff issue you can test it by performing a maximal external rotation resistance against a cable or on the wall. If it feels weak and painful, the rotator cuff probably aren’t happy. Try it again for 40s at 70% of your maximum and if that feels better, then that’s a good starting point for your rehab.
As the bench press is a multijoint exercise, we can’t always use it to target deficits. For example, you may be naturally a “pec dominant” bencher and keep failing just above your chest because your triceps can’t keep up. The more you bench, the better you’ll work your pecs. Or you may be pec deficient, and get pinned right on your chest because the weight was too much to handle during the descent and they’re gassed before you can even press it up.
Recommendations for isolation work in a program is higher frequency (3x/week) with high total volume (10-20 working sets). Reason is, because they are smaller muscle groups, you can smash them hard and heavy and you’ll recover quicker and can therefore fit more sessions in the week.
Some examples if they’re not already in your program:
Horizontal adduction- Pec major (lower fibres)
Shoulder flexion– Anterior delt/ pec major
Elbow extension- Triceps
Determining which scenario applies to you, can be tricky. Which is why a more thorough assessment may be required. If you’re not assessing then you’re guessing. Here at P360, we use an ActivForce dynamometer to give us readings. If it is an issue with the movers, it would be worth adding “activators” or primers pre bench to warm up inhibited structures as well as dedicated isolation work.