Tag Archives: shoulder impingement

Internal Impingement of the Shoulder – PART IV

Last week we visited external impingement in the shoulder, how it arises, and what to do.  This week we’ll take a look at internal impingement.  Internal impingement is a pathologic condition that can lead to a whole host of problems in the shoulder.  The problem is most commonly seen in overhead throwing athletes, tennis players, volleyball players, swimmers, as well as athletes involved in overhead weight lifting. 

Shoulder Mobility and the Fist to Fist PART I

Shoulder Series and the Sleeper – Part II

External Impingement – PART III

Internal impingement is the repetitive contact of the articular surface of the rotator cuff against the posterior superior surface of the glenoid and glenoid labrum.  Essentially, the supraspinatus and infraspinatus become trapped between the humeral head and the rim of the glenoid in the back of the shoulder.  This happens when the arm is abducted and externally rotated or the “high 5” position as I like to refer to it.  When we look at sporting activities this encompasses it’s the exact position for throwing, or serving in tennis. 

Internal impingement of the shoulder: comparison of findings between the throwing and nonthrowing shoulders of college baseball players

Contact between these structures happens naturally but not everyone presents symptomatic with pain.  When internal impingement is ignored rotator cuff and labral fraying can occur which can lead to full on cuff tears SLAP tears, and labral lesions; not a good thing for the shoulder. 

The precise cause of these impingement lesions remains unclear. However, it is believed that varying degrees of glenohumeral instability, posterior capsular contracture, and scapular dyskinesis may play a role in the development of symptomatic internal impingement.

Overhead athletes are pre-disposed to internal impingement purely because of the physiologic adaptations that they develop which include humeral retroversion, anterior laxity, increased external rotation, etc.  The same characteristics that allow an individual to throw hard also cause dysfunction in the shoulder. 

When pitchers lay back into maximal external rotation the head of the humerus is allowed to slide anteriorly in the gleniod.  With the inability to stabilize the humerus dynamically at high speeds the posterior cuff gets pinched between the gleniod and the humerus.  Athletes usually complain of pain on the posterio-superior region of the shoulder when the arm is externally rotated into the throwing position. 

Exact causes of internal impingement aren’t exactly clear but there are several theories on what causes internal impingement but most start with anterior laxity, the inability of the rotator cuff to stabilize dynamically, scapular dysfunction, as well as posterior tightness. 

The first place to start in the rehabilitation of internal impingement symptoms is to restore total motion to the glenohumeral joint, namely the posterior musculature.  This can be done by stretching with the sleeper stretch as well as cross body adduction. 

From there we also want to emphasize strengthening the rotator cuff statically, then dynamically.  Anything to strengthen the cuff and major players in the role of proper scapular function is warranted, especially upward rotation. 

The one thing we don’t want to emphasize is any external rotation stretching.  The anterior capsule is already loose enough due to the nature of their skill.  When we stretch we are concerned with increasing movement through internal rotation. 

The main take home points for internal impingement are to restore motion, especially internal rotation, strengthen the cuff and scapular stabilizers, and look to restore proper motion in the scaps.


External Impingement – PART III

Continuing on with Part III of our shoulder series we come to impingement and its different forms.  There is internal, and external impingement.  Each comes with its own set of problems as well as treatments.  If you haven’t caught the other two previous parts you can find them below. 

Shoulder Mobility and the Fist to Fist – Part I

Shoulder Series and the Sleeper – Part II

Today we will focus on sub-acromial, or external impingement.  There are actually different forms of external impingement.  However, we are going to focus on the secondary form of external impingement as that is generally the more common form that we find working with athletes. 

Like I said last week with new crop of baseball players at my disposal I get to see a new crop of shoulder problems and like everything in the shoulder series that we are going to go over I have a player who tested positive for external impingement. 

So what is sub-acromial, or external impingement and how do we fix it? 

External impingement is when the tendons of the rotator cuff, and/or biceps tendon becomes irritated/inflamed.  All these tendons pass through the small, bony space between the humerus and the acromion.  When this space becomes too tight these tendons rub on the underneath side of the acromion causing inflammation, and pain.  

This can lead to the thickening of these tendons causing more, and more problems.  Over time bone spurs can accumulate on the acromion and in severe cases the rotator cuff can actually be severed.   This mainly happens with overhead activities and is fairly common with throwing athletes, tennis players, and especially swimmers. 

From other posts of mine you may remember the main function of the rotator cuff is to stabilize and depress the head of the humerus.  When the rotator cuff becomes weakened either due to pain, injury, improper training methods, etc. the head of the humerus is allowed to migrate superiorly.  When this occurs the sub-acromial space doesn’t exist and the tendons are being trapped any time there is overhead activity. 

Rotator Cuff and the Towel

Everybody has external impingement.  As we move the humerus overhead the sub-acromial space closes.  It happens to everyone with the only difference being in who presents with pain. 

With external impingement we want to open the sub-acromial space up as much as possible.  More often than not the space has decreased due to a poor posture and compensations.  When we allow the scapula to anteriorly tilt, downwardly rotate and/or protract the sub-acromial space decreases greatly. 

If you slouch in a chair and try to raise your arm overhead it isn’t easy.  The humerus doesn’t move as far into flexion, or as easy, and you might even get a pinch in the front of the shoulder.  But open up the chest, sit up tall with the shoulder blades down and back and the movement is much easier and gives the head of the humerus room to breathe. 

If you haven’t figured it out this also has to do with the scapulo-humeral rythym as well.  If the scapula has a hard time upwardly rotating, then (drum roll please) the sub-acromial space is closed down and we get external impingement. 

Just like in other posts recently, upward rotation of the scap is hugely important in an overhead athlete for this very reason. 

So when we are weak on the backside in the lower and middle traps, and serratus anterior, and tight on the front side in the pec major and especially pec minor as well as the downward rotators we get a scap that’s out of whack. 

This problem is a common theme and I’ve touched on it several times previously. 

Upper Crossed Syndrome I

Upper Crossed Syndrome II

When it comes to external impingement the first thing we want to do is eliminate the area that causes pain, namely anything overhead. 

Everything that we do as far as training must be done without pain.  We want to help correct the poor scapula patterns and even thoracic spine patterns associated with the impingement.  Strengthening the scapular stabilizers is highly important, especially the upward rotators when it comes to movement as well as strengthening the rotator cuff all while using exercises that are pain free and don’t create inflammation.  Don’t let the athlete work through pain or pinches in the sub-acromial region. 

A common theme to strengthening the backside and scaps is that we need to do soft tissue work on the front side.  Lenthening the pec minor especially will go a long way in correcting poor scap patterns.  Just like our upper crossed syndrome states we want to lengthen the downward rotators of the scapula.  This means soft tissue work on the levator scapula, and rhomboids as well.  Eliminating downward rotation of the scapua means increasing the sub-acromial space. 

So are steps will be strengthening the upward rotators of the scap, correcting poor scapular patterns, increasing the strength in the rotator cuff, and lengthening the pecs, and downward rotators all while doing so in a safe unimpinged zone. 

Empty Can vs. Full Can

The Other Shrug

Are your scaps working?