The Forgotten Serratus Anterior

The serratus anterior may be most overlooked muscle in importance for shoulder health in the throwing athlete.  The lower trap (LT), serratus anterior (SA), and upper trap (UT) all work in conjunction to form a force couple known as upward rotation. Upward rotation is of huge importance for shoulder health when it comes to the overhead athlete.  If you can’t upwardly rotate, this is what you have to look forward to?

  • Decreased subacromial space
  • Decreased glenohumeral space
  • Decreased glenohumeral stability
  • Increased shearing forces
  • Altered scapulohumeral rhythm

What can all of the above mean if your an overhead athlete?

  • Subacromial impingement
  • Bursitis
  • Labrum tears
  • Thoracic outlet symptoms
  • Rotator cuff wear

Janda was one of the first therapists to note the tendency for serratus weakness due to postural changes.

–These postural changes decrease glenohumeral stability as the glenoid fossa becomes more vertical due to serratus anterior weakness leading to abduction, rotation, and winging of the scapulae. This loss of stability requires the levator scapula and upper trapezius to increase activation to maintain glenohumeral centration. (Janda 1988)

Sahrmann also noted, in Diagnosis and Treatment of Movement Impairment Syndromes, that upper trapezius activation is needed to compensate for the weakened serratus anterior muscle. The upper trapezius may be supporting the increased activity in the serratus anterior, and consequently increased stress occurs at the glenohumeral, and acromioclavicular joint. (Sahrmann 2002)

A plethora of shoulder problems come from decreased activity in the serratus anterior as well as lower trap. No muscle, or muscles work solely in isolation and when one shuts down others have to pick up the slack.  When this happens the upper trap has no choice but to become overactive in its efforts.  Selecting movements that can inhibit the upper trap while still activating the serratus, and lower trap become important.

Thoughts that should factor when programming training for the overhead athlete and the involvement of the serratus anterior.

  • Exercises that involve balance on an object have been shown to actually increase UT recruitment in lieu of the SA. (Piraua, 2014)
  • The SA becomes more active the further the humerus is away from the torso. As you raise your arm and increase the humeral angle, the SA is involved more and more. Exercises below 80 degrees of humeral angle produce much less activation in the SA.
  • Protraction produces high SA activity levels as well as elevation of the humerus.  In some cases, elevation has shown to be the superior method to recruitment of the SA.  However, exercises that maintained an upwardly rotated scapula while accentuating scapular protraction elicited the greatest EMG activity for the SA.

Here are 3 variations we us on training the serratus anterior.

Elevated Scap Pushup

As stated previously, the serratus is less active in protraction at humeral angles of <80 degress.  Elevating the feet creates a larger humeral angle.  I like to start with the feet on an 18″ box.  Progression may include moving from a normal 12-18″ box into the higher angles created by the athlete and/or the box.  We may cue the athletes to raise the hips into an A-frame pushup while elevated in lieu of raising the box.   As we raise the box, more stress in added to the core and athletes will often lose focus on either the stabilizing the core, or protracting the SA.

Band Serratus Pull Aparts

This is a combination movement we’ve used for years that requires focus, and control throughout to keep the SA fully active throughout the set.  Athletes perform retraction on one side, protraction on the other.

Band Serratus Elevators

Elevators are an exercise I got from physical therapist, Shon Grosse for isolating the serratus.  Using a visual stimulus in front of the hand forces the athlete to continue protracting the blade, or reaching out.  Otherwise, it’s extremely common to “relax back into the movement,” which takes stress off the SA.  We want both active protraction and humeral elevation here.  The combination produces higher levels of SA contraction than just one or the other.  A further progression can include light dynamic stability forcing the cuff to reactively center the head of the humerus while in motion.

  2. S.A. Sahrmann. Diagnosis and Treatment of Movement Impairment Syndrome.  Mosby, St Louis (2002) pp 193–245
  3. Piraua, Andre. Electromyographic analysis of the serratus anterior and trapezius muscles during push-ups on stable and unstable bases in subjects with scapular dyskinesis. Journal of Electromyography and Kinesiology. 10/2014 

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