Shoulder Impingement: Part 1 – What It Is and Why It’s Important

By djpope

January 20, 2018

biceps tendon, bursitis, impingement syndrome, pain front of shoulder, rotator cuff, shoulder injury, Shoulder Pain, subacromial impingement, tendonitis, why

Updated October 2017

I recently had the opportunity to speak with one of my professors Mark Butler, a physical therapist I have a lot of respect for.  I asked him what he thought was the most common shoulder problem in the world of fitness.   His response:

Shoulder Impingement

From my own experience (in the clinic and when coaching) and speaking with other crossfit trainers and therapists, the most common problem area for people in crossfit is the shoulder.  Just take a look at the major exercises in crossfit; overhead press, push press, push jerk, pushups, kipping pullups, snatches, dips, muscle-ups and handstand pushups.  All awesome exercises, all tough on the shoulder.  No wonder we have impingement.

Note: 5 years later, impingement continues to be the #1 most common issue I treat clinically and see in the gym

Unfortunately, the term shoulder impingement is thrown around quite a bit to describe every type of shoulder pain.  In reality there are several different types of impingement, each with unique aspects.  This is why its important to consult a professional if you are concerned you may have an impingement situation.  The problem can be very complex and impingement can be coupled with other issues as well.

In understanding shoulder impingement first we’ll learn the anatomy.  Here are the key structures:

  1. The Humeral Head – This is the top portion of the bone in your upper arm.  Normally it should stay snugly fit centered into its socket, the glenoid fossa
  2. Acromion, Coracoid and Coracoacromial ligament – These structures sit above the humeral head and provide a small space aptly named the subacromial space.
  3. Supraspinatus Tendon (part of the rotator cuff), long head of the biceps tendon and a bursa.  These structures sit between the humerus and the structures labeled above in #2 in the subacromial space.  These are the structures that get impinged upon with this syndrome.

In an impingement scenario, the rotator cuff and scapular musculature is not holding the humeral head firmly into the socket.  Commonly the humeral head translates superiorly (goes up) and the contents of the subacromial space gets pinched (impinged) against either the acromion, coracoid or a combination of the two.

Image SourceLicense, Attribution: Anatomography / CC BY-SA 2.1 JP () – edited by Fitness Pain Free LLC

This can occur with all different movements of the shoulder. Check out the video below to learn a bit more:

An old professor of mine Dr. Kietrys has an excellent saying about impingement.  He says, “All roads lead to shoulder impingement”   What he meant by this is that most types of shoulder pain end up causing some type of impingement.  So regardless of how you hurt your shoulder (overuse, technical breakdown, overstretch, muscular imbalance, poor posture, dyskinesis) it will most likely end up causing a shoulder impingement.  In a lot of cases shoulder pain can lead to a cascade of additional problems (muscle-firing issues, weakness).  Now you’ve got a complex rehabilitation situation on your hands or in some cases, surgery.

As discussed earlier, the impingement can be occurring in multiple places:

  1. Coracoid Impingement
  2. Acromial Impingement
  3. Internal Impingement (Thrower’s Impingement)

Impingement by the coracoacromial arch (a fancy term for the acromion, the coracoid and the ligament that connects the two)  is what we discussed earlier.   It’s also commonly referred to as subacromial impingement.  The most important thing to remember about this condition is that the humeral head is not being held tightly into the glenoid fossa (ball into socket) in the correct position during exercise.  This happens for a variety of reasons we’ll discuss in the next articles.  Because of this we get excessive impingement, pain and eventually damage to the structures within the subacromial space.

In subacromial impingement of the shoulder there is typically a painful arc of motion while raising your arms overhead, usually in the 70-120 degree range.

For this reason a lot of athletes will be able to perform push jerks without much pain but lowering the weight back down under control can be very painful.  When the shoulder is being forced to work through the painful arc it may hurt (strict press or lowering a heavy weight from overhead under control).  When the force is created by the lower body to get the weight overhead and then “caught” in a fully locked out position there is generally less pain because we’re avoiding loading through this painful arc.

These patients also usually have pain when reaching across the body, internal rotation of the shoulder and elevation of the arm into the painful arc of motion as described earlier.  These are a few provocative diagnostic tests to rule in  subacromial impingement syndrome.  Each of these tests creates compression of the cuff, biceps tendon and bursa and is deemed positive if it recreates the patient’s normal pain.

Hawkins Impingement Test

Neer’s Test

Internal impingement is a different beast.  This is an impingement common in throwing athletes and occurs with excessive external rotation of the shoulder seen in pitching and in the tennis and volleyball serve.  Although this impingement is specific to overhead throwers, the motion that causes internal impingement is very close to some exercises that require external rotation of the shoulder in an overhead position (Snatch grip push press, behind the neck press).

Note: I tend to see a lot of athletes who present with a lot of posterior shoulder pain (along teres minor / infraspinatus) and are very tender to palpation of these structures.  These athletes tend not to tolerate external rotation well, especially combined with horizontal abduction (Think of the motion required in a behind the neck barbell overhead press) My thoughts are that are that the posterior cuff muscles are potentially being impinged and required to work excessively and may become painful for those reasons.

Again, please don’t try and diagnose and treat yourself, consult a professional if you’ve got pain.  This isn’t a problem to take lightly.  In the next installments we’ll talk about common causes of impingement and how to specifically prevent these issues in the crossfit population.

Part 2 HERE:

Want to learn more about how to rehabilitate and prevent future shoulder injury?  Check out my latest shoulder course with Dr. Dave Tilley.

Just a few things covered in the course…

  • Functional Shoulder Anatomy: What parts of the shoulder are most relevant to your understanding of injury and performance?
  • The Most Common Shoulder Injuries Seen in the Gym: Shoulder impingement, rotator cuff tears, biceps tendonitis, AC joint injuries, bursitis and labral tears
  • Technical Errors: Advice on where injuries occur in the major lifts and how to fix this
  • Advanced Rehabilitation Strategies: Learn how to bridge the gap between basic rehabilitation and high level performance
  • Progressive Return to Exercise Programs – Specific exercise protocols to help you return back to pull-ups, bench press, muscle-ups, snatching, jerks and overhead pressing

Click HERE to Learn More about Peak Shoulder Performance

Here’s to healthy shoulders,

Dan Pope DPT, OCS, CSCS, CF L1


Behnke, R. S. (2006). Kinetic anatomy. (2 ed., pp. 35-56). Champaigne, IL: Human Kinetics.

Page, P., Frank, C. C., & Lardner, R. (2010). Assessment and treatment of muscle imbalances the janda approach. (pp. 195-207). Champaigne, IL: Human Kinetics.

Wilk, K. E., Reinold, M. M., & Andrews, J. R. (2009). The Athlete’s Shoulder . (2 ed.). Philadelphia, PA: Churchhill Livingstone.