Though it might not seem like the first workout technique you’d think of, a shrug is actually a terrific movement that activates several of your muscles, even though the movement is only happening to one joint of each shoulder.
As a result, a shrug has become a popular workout technique for strength builders, especially because these movements help to strengthen crucial muscles that play important parts in many other strength building activities.
For example, a shoulder shrug works muscles that you use for weightlifting, carrying, bench presses, pull-ups, deadlifts, and more.
In our handy guide below, we’ve got all the information you need of what muscles a shrug will activate and work. You’ll be using this popular technique in no time!
What Do Shrugs Work?
Doing a shoulder shrug workout move will activate various different muscles.
The key one of these is the trapezius muscles (often known as “the traps”), which is a very popular set of muscles that many bodybuilders like to strengthen and show off.
With that being said, the trapezius muscles aren’t the only ones being activated, because other muscles are needed to complete the shrugging motions too.
These collaborative muscles are known as stabilizing and synergist muscles, and they include muscles like the levator scapulae and the erector spinae, among many others.
On top of that, some secondary muscle groups are also at play in a shrug. We’re going to go in depth on all of these muscles now!
The Trapezius Muscles
These are the primary muscles that are activated when you do shoulder shrugs, and they’re some of the most important back muscles you have.
These muscles are found quite close to the surface of your skin, and they’re essential because they’re connected to your shoulder blades, being responsible for allowing them to rotate and move.
Without the trapezius muscles, you’d struggle to raise your arms higher than your shoulders!
The trapezius muscles cover about half of your back, because they go from the middle of your back to the bottom of your neck (or cervical spine). They also help to stabilize your upper body.
You’ll also find that when you’re doing heavy lifts, such as a deadlift, the upper trapezius muscles support your shoulder girdles against the various forces that will be trying to pull them down.
What Happens To Trapezius Muscles In A Shrug?
When you lift your shoulders in a shrug, you will feel the trapezius muscles tighten immediately, because the muscles are contracting.
When you then let your shoulders drop down again, finishing the shrug, you will feel the muscles releasing and relaxing again.
The Stabilizer Muscles
There are various stabilizer muscles activated during a shoulder shrug, and they collaborate with the trapezius muscles we just looked at.
Stabilizer muscles get their name because they work to stabilize your position, contracting themselves to do so.
Erector Spinae
The primary stabilizer muscles for doing shrugs are the erector spinae muscles, which are made stronger by doing shoulder shrugs.
As for their location, the erector spinae muscles go from the lower bit of your neck and your tailbone.
Other Stabilizers
However, the erector spinae muscles are not the only stabilizer muscles that are activated when you do a shoulder shrug exercise.
For one, muscles of your rotator cuff get a workout, as well as a variety of your upper back muscles.
For example, your latissimus dorsi will be activated (which covers most of your lower posterior thorax), as well as rhomboid major and rhomboid minor.
The Synergist Muscles
Performing shoulder shrug exercises will also involve the activation of some of your synergist muscles, which collaborate with the trapezius muscles and stabilizer muscles in order to help you perform the correct motions.
In fact, some of the middle trapezius muscles are synergist muscles.
Levator Scapulae
One of the key synergist muscles that will be involved in shoulder shrugs is the levator scapulae. This is found at the side of the neck, and it helps the shoulder blade to be lifted.
The Secondary Muscles Groups
Finally, you can expect some secondary muscle groups to be activated by shrug exercises.
There’s an enormous range of muscles that could potentially be worked depending on the types of shrugs that you’re doing.
For example, your glutes could be activated, as well as your hamstrings, lats, deltoids, quadriceps, calves, obliques, and more.
In addition to these, you’ll also find that secondary muscle groups in your core and arms will also be activated.
To use an example, if you were doing a shrug with a weight like a barbell, then it would be working your arm muscles, while a shrug with a dumbbell would work your core muscles.
Why Should You Do Shrugs?
As you’ll have seen from all the different muscles that are activated and worked when doing them, shrugs have plenty of benefits.
They Improve Posture
For one, shrugs will help to get a better posture, because they work on your trapezius and shoulder muscles.
With these important muscles tightened and strengthened, you’ll find that your body posture becomes much firmer and more upright.
They Reduce Risks From Other Exercises
Additionally, shrugs help to improve muscles that will be needed for other exercises.
If the muscles aren’t up to the job during other exercises, then you risk getting injured and suffering chronic pain in your upper and lower back.
Thankfully, though, shrugs will help to strengthen the muscles in your shoulders and neck, which are needed for other key exercises.
On top of that, if your trapezius muscles aren’t properly balanced, then it’s also going to increase the risk of you getting injured during other workouts.
As a result, shoulder shrugs will help you to balance the different parts of the “traps”.
Final Thoughts
Shrugs work a lot more muscles than you might think, activating the trapezius muscles, as well as stabilizer muscles, some secondary muscle groups, and synergist muscles.
However, you MUST use proper shrug form: don’t move your shoulder forwards or backwards.