What is Scapular Stabilization?
The socket for your shoulder joint, called the glenoid fossa, sits on the scapula (shoulder blade). The only bony attachment of your shoulder blade to your body is through your clavicle (collar bone). As a result, your shoulder relies heavily on the many muscles that attach the scapula to your spine and ribcage. The ability of these muscles to move and control your scapula is called scapular stabilization.
Serratus Anterior: The Workhorse of the Scapular Stabilizers
The ability to stabilize your scapula is crucial in maintaining or restoring shoulder health. If the muscles that control your scapula don’t work properly, the strength of your pecs, lats and other muscles is irrelevant. Without adequate scapular stabilization and control, these bigger muscles do not have the stable base upon which they can express their strength. It is also important to note that all of the muscles in your rotator cuff originate on the scapula, thus scapular control is also vital for these muscles to work efficiently.
As your arm moves, so too does your scapula. This coordinated movement is called scapulohumeral rhythm. Put simply, for every two degrees of arm movement, there is one degree of scapular movement. With that being said, there is relatively little scapular movement until the arm has moved roughly 60 degrees away from your body. This means that scapular movement/control becomes increasingly more important the higher you need to lift your arm. If you are an overhead athlete, doing a shoulder press in the gym or simply want to reach into the cupboard without pain, you cannot ignore scapular movement!
For arm movements above 60 degrees, the scapular movement know as upwards rotation is essential. This movement rotates your scapula, moving the socket of the shoulder joint along with it. Your scapula moves in a way such that the bottom corner (inferior angle) of the scapula, moves towards your armpit. This prevents your humerus (arm bone) from bumping into the roof of your shoulder joint and crushing your rotator cuff tendons and the subacromial bursa (you can google this structure if you’re curious).
- insert photo for scapular upwards rotation
The primary muscles involved in creating and controlling this movement are upper trapezius, serratus anterior, middle trapezius and lower trapezius. For the purpose of these scapular stabilization posts, we will focus on serratus anterior and middle/lower trapezius. Although upper trapezius is also an important contributor, it is uncommon for people to have difficulty recruiting this muscle. The most important muscle for upwards rotation is serratus anterior. Middle and lower trapezius play more of a synergistic/stabilization role vs directly driving upwards rotation.
insert photo of serratus anterior, trapezius
A common scapular stabilization cue used by both physiotherapists and strength coaches alike is “squeeze your shoulder blade down and back”. This is achieved via a combination of scapular retraction (backwards movement) and depression (downwards movement). This strategy is very effective for stabilizing the shoulder during activities that involve lifting heavy objects while your arm is below 60 degrees – deadlifts, farmer’s carries, bench press or carrying a heavy bag of groceries, to name a few. If you apply this same stabilization strategy to movements above 60 degrees of arm movement, you are directly preventing scapular upwards rotation. You must set your scapula free!
Serratus anterior activation and strengthening:
Babies first develop serratus anterior strength as they are crawling around on their hands and knees. There is no better way to start waking this muscle up in adults than using a similar, albeit more deliberate strategy – exercises in 4-point!
Push-up Plus in 4-point (isometric serratus anterior contraction)
For this version, you will be learning how to engage your serratus anterior in a neutral position without moving your arm. Serratus is a difficult muscle to “feel” as it is very deep and quite broad in its attachment – you won’t feel it or see it work in the same way as you would your biceps with a biceps curl. As long as you focus on the proper set up/technique, serratus will engage. As with any isometric exercise, the degree of effort you put into is proportionate to the amount of muscle recruitment you will get. In other words, if you want to engage the muscle more, push harder!
-embed video for bilateral pushup plus in 4 pt
- Start on hands and knees, with hands under shoulders, knees under hips
- If you have wrist pain in this position, go on your knuckles or hold dumbbells in each hand on the floor
- Let your body hang/relax down between your shoulder blades
- Push body straight up into your shoulder blades/away from the floor without rounding your upper back (this should stay in a neutral position)
- Hold 5 seconds
- Return to starting position of hanging between down your shoulder blades and repeat.
Pushup Plus in 4-Point with Single Arm Hold
(steps 1-4 will be identical to the previous version)
-embed video for pushup plus with unilateral hold
- Start on hands and knees, with hands under shoulders, knees under hips
- If you have wrist pain in this position, go on your knuckles or hold dumbbells in each hand on the floor
- Let your body hang/relax down between your shoulder blades
- Push body straight up into your shoulder blades/away from the floor without rounding your upper back (this should stay in a neutral position)
- Once in this position, lift one hand off the ground
- Push the stance arm firmly into the ground/push body away from the floor as you rotate your trunk 10-15 degrees (chest will face slightly away from your stance arm)
- Hold 5 seconds
- Return to starting position of hanging between your shoulder blades and repeat.
Again, effort/intensity is crucial. If you are just passively hanging on your arm, you will get nothing out of this. You need to actively push as hard as you can – either thinking about pushing your hand into the floor or pushing your body away from the floor (whatever image helps you more).
This next progression is the most important for waking up serratus anterior. We will now focus on the upwards rotation movement of the scapula.
Pushup plus with Scapular Upwards Rotation
(steps 1-6 will be identical to the previous version)
-embed video for pushup plus with scapular upwards rotation
- Start on hands and knees, with hands under shoulders, knees under hips
- If you have wrist pain in this position, go on your knuckles or hold dumbbells in each hand on the floor
- Let your body hang/relax down between your shoulder blades
- Push body straight up into your shoulder blades/away from the floor without rounding your upper back (this should stay in a neutral position)
- Once in this position, lift one hand off the ground
- Push the stance arm firmly into the ground/push body away from the floor as you rotate your trunk 10-15 degrees (chest will face slightly away from your stance arm
- Slowly drop your hips backwards towards your feet
- You can use your legs to slow the movement down/provide resistance for your stance arm to work against.
- Focus on pushing the bottom corner of your scapula towards your arm pit as you drop your hips back (upwards rotation of the scapula)
- Return to the starting positions and repeat
Programming Serratus anterior activation
Sets: 3
Repetitions: 10-15
Hold: 5 seconds per repetition
Rest Interval: 30-90 seconds between sets
Frequency: Minimum 3 times per week (ok to do daily)
Serratus is an endurance profile muscle. So it responds best to higher repetition ranges. All options except for the pushup plus with scapular upwards rotation use a 5 second hold. With the pushup plus with scapular upwards rotation, your legs will always be stronger than your arm, so you can generate a lot of challenge with this exercise depending on how hard you push with your legs. Aim for an intensity of 7-9/10 (0 = no effort, 10 = max effort/failure) by the time you’ve done the last repetition of the 3rd set.
If you are doing this exercise along with your usual gym routine, save it for the end of the workout. This muscle is an important stabilizer, so if you pre-fatigue it before you do your other lifts, you may comprise your ability to properly stabilize your shoulder. You could however, do one set of 10-15 as a warm-up.