Muscle Contractions and Function: All Muscles Pull
There are no “push” muscles
In my last blog post I was discussing program design and the best way to create effective, efficient workouts. At one point I made the comment that, technically, all muscles pull, there is no such thing as a muscle that pushes. And I’ve gotten some questions about what I meant by that. Because when you’re doing a push-up or bench press or a squat, you’re clearly pushing something.
how can there be no push muscles?
I thought I’d give a quick explanation as to what I meant. Because there are definitely movements that involve pushing. But the reality is that the only action a muscle can perform is a contraction, which is what we would consider a pulling movement or the shortening of muscle tissue.
There are multiple versions of a muscle contraction but regardless, they are all still that: a contraction. The most common one we know is called concentric. This is the straightforward motion of pulling something in and the muscle tissue contracting and shortening against resistance or gravity. There is also isometric, which is maintaining an unchanging contracted state of the muscle so it is neither lengthening nor shortening. This is when you hold a position, and probably everyone’s second least favorite exercise movement. Pilates and yoga tend to utilize a lot of isometric holds.
Followed by probably everyone’s #1 least favorite exercise movement: eccentric. Many of you will know this by the term, “performing a negative”. This is when you control the speed of the muscle contraction against resistance or gravity in either direction, but most commonly in the direction of gravity.
An example of this is when you do a deadlift but on the way back down you instead work against gravity while still moving in the same direction as gravity to slowly lower the weight back to the ground. This is a great way to improve control, increase muscle strength and especially muscle endurance as it increases the time under tension of the muscles involved.
I’m pretty sure they added a fourth term to this list of muscle actions after I took the trainer exam a hundred years ago, but I think it was just to expound on the subtle nuances of things that our muscles can do. If you need to know I can look it up for you and break it down. But first let me give you some examples of push exercises that are still you pulling.
Examples of PUshing Exercises That are actually pulling
In a push-up, bench press, or overhead press there is clearly a push movement occurring. But when you break down the movement there are primarily two things happening. Your chest muscles and the muscles of the front of your shoulder attach to your humerus bone, or the bone of your upper arm, and during a push-up or bench press, those muscles lengthen as your arm moves away from your body (think the bottom of your push-up). But when you are “pushing” yourself back up or “pushing” the barbell away from your chest, what is happening are the chest and should muscles contracting and shortening and pulling your arms back towards your body. Mechanically it’s the same thing as performing a chest fly. So while the movement appears to be a push, it is really your chest and shoulder muscles contracting to pull your arms back toward your body. How this differs from a chest fly is because you’re adding in the bend of your elbow, which is also a pull movement. At the bottom of your push-up or bench press or overhead press, your elbow is bent. As you “push” the weight away your elbow begins to straighten out, which is caused by your tricep muscles (the muscles on the back of your upper arm) contracting and pulling your arm back into a straight position. And it is the combination of those three muscle groups contracting that allow you to “push” yourself off the ground or “push” a barbell off your chest. Two main muscles pull your arm back towards your body and your triceps pull your elbow back into a straight position.
It’s a similar situation if we break down a squat. If you’ve ever used a leg extension machine to work your quads you know that the work is done when you go from a bent knee position to straightening your leg out. Similar to how your triceps work this is due to your quadriceps being in a lengthened position when your knee is bent, and then they contract and shorten and pull your leg into a straight position. If you think about your squat mechanically, your knees are bent at the bottom of your squat. As you “push” yourself out of the bottom position and back to standing, your quadriceps are shortening and contracting in order to pull your leg into a straight position.
The one people are less familiar with is a hip extension. Any time your leg is moving from front to back that is considered a hip extension. The muscles of your glutes and hamstrings are pulling your leg back from whatever front position it started in. If you once again consider the position of your squat at the bottom, when you feel like you’re “pushing” yourself back up to a standing position, your glutes are actually contracting and pulling your upper leg backwards to get you into that standing position that’s the start of your squat. There are other muscles involved in all this but those are the main two for this explanation. You also have adductors that are contracting and pulling your leg from an externally rotated position towards an internally rotated position, but that is probably going to overly complicate things.
So there you have it! Muscles contract and pull, and any time you are performing a push exercise it is still some group of muscles pulling and contracting to move your body. Side note: this is also why true pull exercises tend to be easier to increase weight on since they are performing the most straightforward version of what your muscles are intended to do.
Thanks for reading and I hope this makes sense! Hit me up in the comments with any questions or thoughts, and if you’re interested in signing up for training submit a consultation form! I’m currently offering free consultations and movement assessments.