Wednesday Rehab – Serratus Weakness or Muscle Imbalance?

Cerritos Assessment by Experiment 

“Experimenting helps you Assess and see what works”. If a trigger point release helped the pain, or if a new cue helps, or a different set-up for an exercise looked better, then “Why?”. Of course you would continue on with doing what works and build upon that in your corrective exercise and rehab.

So in our Assessment, we might be asking the question:
“If my client is winging at their Scapula during push-up or plank, can we know if that is due to Pec Minor dominance, or due to Serratus weakness? In other words is it a classic muscle imbalance between the two, or just a weak Serratus?”

How can we Assess this by Experimenting? To help explain the point, permit me to use what Chris Mallac wrote recently about Serratus and Pec Minor:

From Chris

Trainers/therapists often claim they see a “winging” scapula (the medial borders of the scapula will stick outward and create a large valley between the shoulder blades – see photos below) and conclude that the client has a weak Serratus Anterior. And no doubt, if you were to grab 10 subjects and ask them to do a push up, or to hold a plank position, most likely 9 out of the 10 will show scapula winging especially as they fatigue.

But is this due to genuine weakness in the serratus anterior, or due to a dominance of another protraction muscle, the pectoralis minor? The easiest way to assess this is to ask them to do a “plus” movement (the experiment). This is an active protraction of the scapula. If the scapula corrects and closes down onto the ribcage then there is a strong argument that the main fault is pec minor dominance (a muscle imbalance rather than classic weakness, as they are able to correct it actively).

To fix this they may need lots of triggering and releasing of pec minor.

If, however, the scapula stays up high and proud even when asked to do the extra “push”, then chances are it is more to do with serratus anterior weakness. To fix this they will need lots of direct serratus anterior activation exercises. I have included some good examples of these two variations in the photos below.









Client #1 demonstrating Scapular winging on push up bilaterally






Winging corrects on execution of a “plus” – 

classic example of mild muscle imbalance causing winging








Client #2: Scapular winging on push up bilaterally
(his Right greater than Left)









Left scapula corrects with “plus” however note the his Right is still winged – truly weak and disengaged Serratus that will need a ton of activation and strength work.