Scapular Instability – 68% and 100%

Many times we often forget that the rotator cuff is not the end all be all with protecting pitchers and the throwing athlete. When the scapula is unable to stabilize, the shoulder, and rotator cuff is where problems occur.  Injuries often occur because of dysfunction above or below the injured segment.  When hamstrings are problems, glute activation is the first piece of the rehab puzzle.  When low back issues are present, we look at the hips.  It’s no different in the shoulder.

When the scapula fails to perform its stabilization role, shoulder complex function is inefficient, which can result not only in decreased neuromuscular performance but also may predispose the individual to injury of the glenohumeral joint.

Here are some take home points from a great paper, The Role of the Scapula by Paine, and Voight in the IJSPT

  • Main scapular stabilizers: Rhomboids, Levator Scapulae, Trapezius, Serratus Anterior.
  • EMG analysis has demonstrated a high level of rhomboid activity during the acceleration phase of pitching. EMG data suggests that the rhomboids are contracting eccentrically during the follow‐through phase of throwing as the muscle continues to contract eccentrically to “brake” the energy released during acceleration. Rhomboid strength is vital in throwing and overhead arm movement.
  • The middle trapezius is highly important for retraction.   The lower trap contributes to upward rotation as well as posterior tilt and external rotation of the scapula during arm elevation.
  • Posterior tilt of the scapula may be the most important aspect to injury prevention in the shoulder of an overhead athlete.
  • Many factors contribute to problems including bony anatomy of the clavicle, posture, and previous injuries.
  • The majority of biomechanics problems and overuse injuries in the shoulder girdle are attributed to the dysfunction scapular stabilizers.
  • Weakness leads to abnormal positioning, disturbances in scapulohumeral rhythm, and shoulder complex dysfunction.
  • The serratus anterior and lower trapezius are the most commonly weak muscles.
  • Paralysis of the serratus anterior results in reductions in both shoulder flexion and abduction. The medial border of the scapula is elevated off the rib cage, resulting in decreased acromial elevation and manifests itself through impingement.
  • In fact, scapular instability is found in as many as 68% of rotator cuff problems and 100% of glenohumeral instability problems

What should be noticed is how necessary the scapular stabilizers are to an overhead athlete.  The rotator cuff gets all the play when it comes to talking about injury prevention with pitchers but without the strong foundation of the scapula, the rotator cuff means little.   Two-thirds of rotator cuff problems and 100% of shoulder problems can be traced back to the scapular stabilizers and most importantly the LOWER and MIDDLE TRAP, SERRATUS, and RHOMBOIDS.  How do you train those???  Well here’s a start.
This is our ISO T / DYN Y on a low incline for training the low and middle trap.  Y’s and T’s are a staple of our program.  This is an advanced progression we utilize to disassociate the arms, and scaps.  This requires much more focus than the normal YTW series and reinforces scapular control.  We use rep ranges of 10-20 per arm on this exercise for 2-4 sets throughout our workouts.

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