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Shoulder Impingement – 3 Keys to Assessment and Treatment

Shoulder impingement is a really broad term that is used too often. It has become such a commonly used junk term, such as “patellofemoral pain,” especially with physicians.

Other common variations include subacromial impingement or rotator cuff impingement, but it seems as if any pain originated from around the shoulder is often labeled as “shoulder impingement.”

Unfortunately, the use of such a broad term as a diagnosis is not helpful to determine the treatment process. There is no magical “shoulder impingement protocol” that you can pull out of your pocket and apply to a specific person.

I wish it were that simple.

This is also why conclusions are difficult to be drawn from meta-analysis and systematic reviews. A paper looking at hundreds of people age 25-65+ with “shoulder pain” isn’t going to provide much clarity, it’s too diluted.

Luckily, a thorough examination can be used to determine the best treatment plan. Each person will likely present differently, which will require variations on how you approach their shoulder rehabilitation.

Most of the clinical examination for shoulder impingement involves provocative tests. Those are great, but the real challenge when working with someone with shoulder impingement isn’t figuring out that they have shoulder pain, that’s fairly obvious. That’s why they are there.

It’s figuring out WHY they have shoulder pain, and what to do about it.

Shoulder Impingement: 3 Keys to Assessment and Treatment

To make the treatment process for shoulder impingement a little more simple, there are 3 things that I typically consider to classify and differentiate shoulder impingement.

  1. The location of shoulder impingement
  2. The structures involved
  3. The underlying cause of shoulder impingement

Each of these can significantly vary the treatment approach and how successful you are treating each person.

If you approach each patient with these 3 things in mind, you are going to do a much better job developing an effective treatment plan, versus just trying things and hoping they work.

I’ve called this the corrective exercise bell curve in the past. If you just throw the same treatments at every person with shoulder pain, you’ll probably get lucky 20% of the time, make them worse 20% of the time, and simply waste your time the rest.

Let’s dig in…

Location of Shoulder Impingement

The first thing to consider when evaluating someone with shoulder impingement is the location of impingement. This is generally in reference to the side of the rotator cuff that the impingement is located, either the outside of the rotator cuff or the undersurface of the rotator cuff.

These are broken down into either:

  1. Bursal sided shoulder impingement – this is your traditional subacromial impingement
  2. Articular sided shoulder impingement – this is called internal impingement
shoulder impingement - bursal articular side

Bursal Sided Shoulder Impingement

See the photo of a shoulder MRI above (photo credit). The bursal side is the outside of the rotator cuff, shown with the red arrow. This is probably your “standard” subacromial impingement that most people refer to when simply stating “shoulder impingement.”

This is often called subacromial impingement because of the location of impingement occurs between the rotator cuff and the undersurface of the acromion, hence the term “subacromial.” This is also called the bursal side of the rotator cuff because there is a bursa located between the rotator cuff and the acromion, which acts as a shock absorber.

Articular Sided Shoulder Impingement

The green arrow shows the undersurface, or articular surface, of the rotator cuff. This Impingement on this side is often termed “internal impingement” because the impingement occurs on the inside, or joint side, of the rotator cuff. If you look closely in the image above, the yellow arrow shows an articular sided partial thickness rotator cuff tear. Note the irregularity of white at the bottom of the dark line of the rotator cuff.

This often involves the supraspinatus and infraspinatus rotator cuff muscles as the undersurface impinges against the glenoid joint rim. I’ll go over this in more detail below.

The two types of impingement are completely different and occur for different reasons, so this first distinction is important.

Because the cause of shoulder impingement is so different, the evaluation and treatment of subacromial and internal impingement will also be completely different. More about these later when we get into the evaluation and treatment.

Impinging Structures Involved

The next factor to discuss is which structures are involved in the shoulder impingement. This is more for the bursal sided, or subacromial impingement, and refers to what structure the rotator cuff is impinging against.

Take a look at the shoulder from the side view, with the front of the shoulder to the right and the back of the shoulder to the left. You can see the acromion is superior and the coracoid is a little more anterior. The coracoacromial ligament runs between these two areas.

shoulder impingement - subacromial space acromion coracoid coracoacromial arch subcoracoid

As you can see in the image, your subacromial space is pretty small (the red areas). It’s pretty easy to impinge on the acromion, coracoid, or coracoacromial arch. There isn’t a lot of room for error. In fact, this really isn’t a blank “space”, there are actually many structures running in this area including your rotator cuff and subacromial bursa.

Get ready… I’m about to blow your mind…

You actually “impinge” every time you move your arm. We all do.

That’s right, impingement of these structures itself is normal and happens in all of us every time we use our arms. It’s when this becomes abnormal, excessive, or too frequent that shoulder pain and pathology occurs.

This is why it is very shortsighted to say “impingement” is normal and that people should work through their discomfort. Yes, some impingement is normal, but excessive impingement is what may cause pain and pathology down the road.

So when it comes to the structures involved in impingement, I try to differentiate between subacromial and coracoacromial arch impingement. These can happen in combination or isolation and typically involve the supraspinatus rotator cuff muscle.

Another area that has received more attention lately is the subcoracoid space or the area below the coracoid. You can also have subcoracoid impingement. Because this is located more anteriorly, the subscapularis rotator cuff muscle can be involved with subcoracoid impingement.

The three types of bursal sided impingement are fairly similar in regard to assessment and treatment, but I would make a couple of mild modifications for coracoacromial and subcoracoid impingement, which we will discuss below.

So if we were to get very specific, you can break shoulder impingement down into four different types based on the location and structures involved:

Bursal sided impingement:

  • Subacromial impingement – Involves the supraspinatus and acromion
  • Coracoacromial impingement – Involves the supraspinatus and coracoacromial arch
  • Subcoracoid impingement – Involves the subscapularis and coracoid

Articular Sided:

  • Internal impingement – Involves the supraspinatus and infraspinatus and glenoid rim

See what I mean? How can all of these be “shoulder impingement?” They all involved different muscles, different impinging structures, different locations, and different mechanisms!

OK, great, we now have differentiated and know “what” is impinging, we still don’t know “why” the person has impingement.

Cause of Shoulder Impingement

The next thing to look at is the actual reason why the person is experiencing shoulder impingement.

There are two main classifications of causes that I refer to as “primary” or “secondary” shoulder impingement.

Primary Shoulder Impingement

Primary impingement means that the impingement is the main problem with the person.

A good example of this is someone that has impingement due to anatomical considerations, with a hooked tip of the acromion like this in the picture below. Many acromions are flat or curved, but some have a hook or even a spur attached to the tip (drawn in red):

acromion tip hook osteophyte

This also happens with the coracoid and subcoracoid impingement. An anatomical variation of the coracoid or bone spur can be present.

As our knowledge of shoulder impingement improves, it appears that the larger a bone spur, the more problematic it may become.

This is referred to as primary impingement because improving things like mobility, strength, and dynamic stability may be ineffective as there is a primary cause of impingement causing the symptoms.

Sure we may improve the symptoms and often times are successful with rehabilitation, but sometimes we aren’t. It’s not because a certain treatment “isn’t effective for shoulder impingement.” It’s because there is a primary reason why impingement is occurring that we can’t change.

Without addressing the primary issue, like a large bone spur, working on secondary issues may not be effective.

Secondary Shoulder Impingement

Secondary impingement means that something else is causing impingement, perhaps their activities, posture, lack of dynamic stability, or muscle imbalances are causing the humeral head to shift in its center of rotation and cause impingement.

The most simple example of this is weakness of the rotator cuff.

The rotator cuff and larger muscle groups, like the deltoid, work together to move your arm in space.

The rotator cuff works to steer the ship by keeping the humeral head centered within the glenoid. The deltoid and larger muscles power the ship and move the arm.

Both muscles groups need to work together.

If rotator cuff weakness is present, the cuff may lose its ability to keep the humeral head centered. In this scenario, the deltoid will overpower the cuff and cause the humeral head to migrate superiorly, thus impinging the cuff between the humeral head and the acromion:

rotator cuff biomechanics - supraspinatus deltoid line of pull

This is just a simple example, but as you can see is very impactful for shoulder function. It’s not just weakness of the rotator cuff, it’s also imbalanced strength ratios and improper timing of dynamic stabilization.

Other common reasons for secondary impingement include mobility restrictions and poor dynamic stability of the shoulder, scapula, and even thoracic spine.

All of these areas need to work together to produce optimal shoulder function.

I see this a lot in my patients.

In the person below, you can see that they do not have full overhead mobility, yet they are trying to overhead press and other activities in the gym, flaring up their shoulder.

shoulder impingement overhead mobility

If all we did with this person was treat the location of the pain in his anterior shoulder, our success will be limited. He’ll return to the gym and start the process all over if we don’t restore this mobility restriction.

The funny thing about this is that people are rarely aware that they even have this limitation until you show them.

Also, keep in mind that this is not “chronic pain.” Sure this person has had shoulder pain for 8 months, but it’s because they keep irritating the area. This is more like recurring acute pain.

Differentiating Between the Types of Shoulder Impingement

In my online shoulder program on the Evidence Based Evaluation and Treatment of the Shoulder, I talk about different ways to assess shoulder impingement that may impact your rehab or training. There are specific tests to assess each type of impingement we discussed above.

The two most popular special tests for shoulder impingement are the Neer test and the Hawkins test.

In the Neer test, the examiner stabilizes the scapula while passively elevating the shoulder, in effect impinging the humeral head into the acromion.

In the Hawkins test, the examiner elevates the arm to 90 degrees of abduction and forces the shoulder into internal rotation, impinging the cuff under the subacromial arch.

As I mentioned earlier, these special tests for shoulder impingement are provocative in nature, meaning that we are looking for reproduction of pain.

Both of them will cause the structures to impinge in all of us, but they shouldn’t produce pain. But if the area is sensitive and irritable, they will cause pain.

You can alter these tests slightly to see if they elicit different symptoms that would be more indicative to the coracoacromial arch or subcoracoid types of subacromial impingement.

Because these structures are more anterior, we can alter the tests to better assess this area.

The Neer test can be performed in the sagittal plane, and the Hawkins test can be modified and performed in a more horizontally adducted position. Both of these positions will impinge more anteriorly.

shoulder impingement special test - hawkins kenedy test neer test.jpg

There is a good chance that many patients with subacromial impingement may be symptomatic with all of the above tests, but you may be able to detect the location of subacromial impingement (acromial versus coracoacromial arch) by watching for subtle changes in symptoms with the above four tests.

Now, before we go any further, let’s talk briefly about the reported accuracy of these tests in the literature.

Just like we’ve talked about with the studies looking at the treatment effectiveness in people with shoulder impingement, most studies published vaguely look at how accurate a test may be at detecting “impingement.” Hopefully, if you’ve gotten this far in the article, you see how flawed this approach is, as this is simply too broad.

How can we evaluate how “specific” a special test is for such a “non-specific” diagnosis?

Internal impingement is a different beast.

This type of impingement, which is most commonly seen in overhead athletes, is typically the result of some hyperlaxity of the shoulder in the anterior direction.

As the athlete comes into full external rotation, such as the position of a baseball pitch, tennis serve, volleyball serve, and others, the humeral head slides anterior slightly causing the undersurface of the cuff to impingement on the inside against the posterior-superior glenoid rim and labrum.

shoulder internal impingement

This is what you hear of when baseball players have “partial thickness rotator cuff tears” the majority of the time. They aren’t the same partial thickness tears your grandmother has.

The best special test for internal impingement is simple and is exactly the same as an anterior apprehension test.

The examiner externally rotates the arm at 90 degrees abduction and watches for symptoms. Unlike the shoulder instability patient, someone with internal impingement will not feel apprehension or anterior symptoms. Rather, they will have a very specific point of tenderness in the posterosuperior aspect of the shoulder (below left). When the examiner relocates the shoulder by giving a slight posterior glide of the humeral head, the posterosuperior pain diminishes (below right).

3 Keys to Treating Shoulder Impingement – How Does Treatment Vary?

Using the three main keys from the above information, you can alter your treatment and training programs based on the specific of impingement exhibited:

  1. The location of shoulder impingement – bursal or articular sided impingement
  2. The structures involved – Subacromial, coracoacromial arch, subcoracoid, or internal impingement
  3. The underlying cause of shoulder impingement – primary or secondary.

I promise you are going to have much more success in designing a physical therapy or training program if you factor in these keys.

Treating Different Types of Impingement

As I hope you can now see, to properly treat shoulder impingement you should differentiate between subacromial, coracoacromial, subcoracoid, and internal impingement.

Treatment is similar between these types of impingement. There is a bunch of overlap.

However, there are some differences:

  • With subacromial impingement, you should be cautious with overhead activities that produce discomfort
  • With the more anterior-based coracoacromial arch and subcoracoid impingement, you need to be cautious with elevation in more of a sagittal plane and horizontal adduction movements that produce discomfort
  • With internal impingement, you should be cautious with excessive external rotation at 90 degrees abduction (like the throwing position) that produce discomfort

Notice that I said “that produce discomfort” for all three? The key here for me is that you should not work through discomfort or a “pinch” with impingement.

A “pinch” is impingement of a sensitive structure!

I’m not a fan of working through pain with shoulder impingement. That to me shows me that you either have a primary or secondary cause of impingement that hasn’t been addressed. Trying to work through this could actually just irritate it more.

Treating Primary Versus Secondary Shoulder Impingement

This is an important one and often a source of frustration in young clinicians.

If you are dealing with secondary impingement, you can treat the person’s symptoms all you want, but they will come back if you do not address the underlying reason why they have symptoms.

But please remember, I do treat their symptoms, that is why they have come to see me.

I want to reduce discomfort and inflammation. This is going to allow me to do more in the long term. However, this should not be the primary focus if you want long term success.

This is where a more global look at the patient, their posture, muscle imbalances, and movement patterns all come into play. Breakthrough and see patients in this light and you will see much better outcomes.

You should have a systemized way of assessing movement and building programs to optimize and enhance their function. If you don’t you really should check out my system in my free online Introduction to Performance Therapy and Training course.

Introduction to performance therapy and training - laptop mockup

A good discussion of the activities that are causing their symptoms may also shed some light on why they are having shoulder pain.

Again, using the example above, if you don’t have full mobility and try to force the shoulder through this motion restriction you are going to likely cause some irritation.

This is especially true if you add speed, loading, and repetition, such as during many exercises in the gym.

I spend a great deal of time discussing what “zones” of motion the person should be working in. Essentially, I try to develop a “green zone” and a “red zone” depending on when they have symptoms.

Shoulder overhead elevation mobility

It’s important to continue working within their green zone and not simply say “take a few weeks off.” And slowly over time, our goal is to expand their green zone and reduce their red zone.

Treating Internal Impingement

Internal impingement involves a little more discussion. The main thing to realize with internal impingement is that this is pretty much a secondary issue. It is going to occur with any cuff weakness, fatigue, or loss of the ability to dynamically stabilize.

The overhead athlete will show some hyperlaxity in the “lay back” shoulder position of external rotation. Most overhead athletes have underlying laxity, what tends to happen is they lose strength or have an excessive workload that causes fatigue and then the structures impingement more and become irritable.

Treat the cuff weakness and its ability to dynamically stabilize to relieve the impingement. This often includes an initial period of rest and then building back their strength and dynamic stability.

How to treat internal impingement is a huge topic that I cover in a webinar for my Inner Circle members.

Learn Exactly How I Evaluate and Treat the Shoulder

If you are interested in mastering your understanding of the shoulder, I have my acclaiming online program teaching you exactly how I evaluate and treat the shoulder.

mike reinold shoulder seminar

The online program takes you through everything you need to become a shoulder expert. You can learn at your own pace in the comfort of your own home. In addition to shoulder impingement, you’ll learn about:

  • The evaluation of the shoulder
  • Selecting exercises for the shoulder
  • Manual resistance and dynamic stabilization drills for the shoulder
  • Nonoperative and postoperative rehabilitation
  • Rotator cuff injuries
  • Shoulder instability
  • SLAP lesions
  • The stiff shoulder
  • Manual therapy for the shoulder

The program offers CEU hours for physical therapists and athletic trainers. Click below to learn more:

Assessing Overhead Arm Elevation – Video Case Study

Assessing overhead arm elevation is one of the many things I look for during my integrated movement assessment.  This is a big part of the Champion Performance Specialist program.  The information you gather on the person’s ability to perform such a basic task is often invaluable when designing someone’s rehab or training program.

I have a video below of an assessment I performed that I wanted to share.  It’s an interesting case with a bunch of movement compensations.  I thought it would be nice to outline my thought process

But first, let me give you a little history…

The patient is a competitor high school swimmer with insidious onset of bilateral generalized shoulder discomfort and fatigue in the pool after prolonged swimming.  He had been seeing another clinician for soft tissue treatments in the past (hence the cupping marks.  His laxity was mostly posterior in nature, but certainly multidirectional.  The exam obviously reveals generalized laxity you would expect with a swimmer, however no significant structural pathology detected.

Here’s what I saw:

Pretty interesting, right?  Scroll down to the comments section and let me know what you think!

Let’s dig into some of my thoughts.

 Assessing Overhead Arm Elevation

  • I would first comment and state that this is one quick video in a long series of assessments.  I chose overhead elevation because it was simple and reproducible  and showed a bunch of interesting things!  I start my assessment off by simple asking them to raise their arms over head.  That is it.  No other instructions.  I feel that it is important to assess how “they” want to move, not how “I” want them to move. assessing overhead arm elevation
  • A test like overhead elevation in the sagittal plane, such as in this video, assumes two thing: symmetry and neutrality.  I don’t think either of these exist.  So it is inherently flawed.  Think about it, if his scapulae are off, then doesn’t that mean his glenoid is off?  Then technically the “sagittal” plane is just in relation to the ground, not to his body.
  • There is also a “chicken and the egg” concept here.  Did his pain create the dysfunctional movement or vice versa?  Unfortunately in retrospect we’ll never know.  Taking this into consideration I don’t think it is fair to assume that anything we are seeing is the “cause” of his pain.  Essentially it is all just the summation of where we are today.
  • Many people often want to jump right in and label specific muscles, such as being “tight,” “long,” “short,” or “weak.”  Remember all we know here is that he has a movement dysfunction.  I think it is appropriate to suggest these may be true, but you will need to take the next step and assess these assumptions.  I wouldn’t just jump in and treat based on assumptions.
  • I should also comment on the marks on his back.  One relevant, the other not so relevant.  The circles are cupping marks.  He is seeing another provider that performs this as part of his maintenance program while swimming in addition to massage etc, not for treatment of his symptoms.   However, the horizontal marks on his low back are relevant.  Those are stretch marks.  More on this later…

Static Scapula Position

  • I have commented on this before in my article on Myths of Scapula Exercises, but I don’t put a lot of emphasis on resting static scapular position.  Realistically, the scapula sits on the ribs, so it’s resting static posture is likely more a reflexion of rib and thorax position that scapular position.  I prefer to look at scapular dynamic movement quality.
  • Interestingly, you can see his dynamic concentric control of his scapulae doesn’t seem as bad as you would think based on his static resting position, especially as he gets high into elevation:

static and dynamic scapula position - assessing overhead arm elevation

The Head Wiggle and Scapula Wing

  • The first thing that really stuck out to me was his head wiggle.  I bet you missed it the first time!  A very interesting movement pattern.  In retrospect, you can find him shift his neck in this fashion quite a bit while observing him moving around and performing activities, even just talking to you sometimes.  It is not limited to just overhead elevation in the sagittal plane.  
  • We can’t really separate this from his winging scapula, they go together.  It sure looks like the head wiggles when the scapula wiggles.
  • To me, this looks like the levator scapula pulling the head with a complete lack of opposition from the lower trapezius and serratus anterior.  His head goes into side bend to the left and extension.  This is the cervical responsibility of the levator.  However, his scapula also shoots up into elevation and downward rotation.  This is my biggest indicator that levator is the one acting.  There could be more involved, like SCM, but I’m focusing on levator.
  • There is obviously some winging and lack of opposition of the levator by the traps and serratus.  This is really obvious on eccentric lower.  He also does not have a painful arc during this movement.  He is not shifting away from pain.

scapula winging - - assessing overhead arm elevation

  • So while the levator may be causing the head wiggle, it sure looks like the serratus and lower trap are not doing their job and creating the scapula wiggle.
  • See how everything plays together?

 

The Elbow Wiggle

  • Did you notice the elbow wiggle?  I don’t think this is really an elbow issue.  If you watch closely he keeps his hand in the same position.  He essentially fixes his hand on an imaginary sagittal plane track.  To me his shoulder and scapula want to move into adduction and internal rotation with the beginning of his scapula winging about to occur.  I feel like his glenoid may be the one the is not stabilized.  Since we have forced him to perform a strict overhead assessment in the sagittal plane, he is keeping his hand fixed and his elbow has to hyperextend to not allow his hand to horizontal adduct.  Again, just shows some of the flaws of assessments like this.

elbow compensation - assessing overhead arm elevation

  • So while this may be glenohumeral instability, I think it is still just the scapula as it occurs during the eccentric lowering and he has almost no ability to control winging.  And again, he does not have a painful arc.
  • This really illustrates a general point that I tend to make about humans in general, but even more so on high level athletes.  We are excellent at getting from point A to point B.  It’s all about how we get there.  Unfortunately the overhead elevation assessment uses an internal cue to “raise your hand up in front of you.”  Perhaps it would be better to give an external cue like “reach up and touch the ceiling.”

 

Thoracolumbar Flexion

  • So taking away all the interesting things happening from the scaps up, I also notice some interesting thoracolumbar compensations.  Remember, this client is a swimmer, and a high level swimmer.  Is it me or does his left latissimus look too small for a swimmer?
  • I mentioned earlier the stretch marks on his lower back.  When he tries to pull down with his arms with any resistance, his movement compensation was to go into a large amount of thoracolumbar flexion, which is a compensatory movement for the inability to extend his arms against resistance.  His lumbar paraspinals show hypertrophy.  So while this could be poor core control, I feel that may be too simplistic.  He goes into thoracolumbar flexion with minimal resistance.  Seems more compensatory rather than poor patterning.  In the photos below, that is not just paraspinal hypertrophy, that is also flexion:

latissimus - assessing overhead arm elevation

  • In looking at the photos above, see how he moves into thoracolumbar flexion?  These are fairly recent photos.  Here are a couple of photos from two months prior.  You can really see the thoracolumbar flexion compensation.  But also notice the dramatic increase in body composition in 2 months.  He put on 15 pounds of muscle mass in a 2-month program designed specifically for him:

thoracolumbar compensation - assessing overhead arm elevation

  • One thing I mentioned was that he feels symptoms with prolonged swimming.  He actually fatigues out well before his fellow swimmers.  Feels strong and swims well, then hits a wall quickly from 10-20 minutes in the pool, while everyone else is in there for 60-120 minutes without complaints.  While he looks a lot better.  There are still some muscles that are not coming back as expected, and he is still fatiguing out in the pool and feeling generalized symptoms.
  • This really makes me question a nerve issue that is just not allowing proper muscle function, and/or the fact that he is essentially swimming with his accessory muscles like his teres major and deltoids.  This is something we need to explore further.

 

Conclusion

Assessing overhead arm elevation is an important part of my overall movement assessment process.  There are many compensations that I typically see, but most don’t present as complex as this video case study.  I hope you enjoyed reading through my breakdown of how I assess overhead arm elevation and some of the things running through my mind!

Comment below if you think I missed anything!

Interested in learning my whole movement assessment system?  It’s a part of my Champion Performance Specialist program, where you’ll learn our exact system of assessing movement, then optimizing and enhancing performance.  It’s exactly what all the physical therapists and strength coaches follow at Champion when building our performance therapy and training programs.

 

Champion Performance Specialist - laptop mockup

 

 

Does Subacromial Decompression Surgery Really Do Anything?

Subacromial decompression surgery is a very common procedure performed for people with shoulder pain.  The procedure is often recommended for people with “shoulder impingement” and was originally theorized to open up the subacromial space and help reduce biomechanical impingement.  

But recent research has challenged the effectiveness of the procedure, and even the diagnosis of “subacromial impingement” itself.

Subacromial Decompression Surgery for Adults with Shoulder Pain: A Systematic Review with Meta-Analysis

A recent article in the British Journal of Sports Medicine reviewed the results of 9 clinical trials in over 1000 patients with shoulder pain.  The authors includes studies that compared subacromial decompression surgery with placebo surgery and exercise therapy.

The study noted that subacromial decompression surgery provided no important benefit compared with placebo surgery or exercise therapy. 

In particular, they found that surgery did not provide any additional benefit for pain, function, and quality of life at the 6- and 12-month mark after surgery.

As you can see, there does not appear to be a significant benefit in undergoing subacromial decompression surgery for shoulder pain or function.

What’s All This Mean?

Based on the results of several studies recently, it sure looks like we’re going to be seeing less subacromial decompression surgeries in the future.

It seems like the benefit of undergoing surgery may be related to the postoperative rehabilitation and application of graded exercise postoperatively.

This is another one of those surgical procedures that seems like it was missing the boat anyway.

Thinking purely biomechanically, rather than addressing the underlying concern that may be causing “impingement,” such as stiffness or loss of dynamic stability, we simply just make more space?  

Seems overly simplistic, right?

We probably haven’t address the underlying cause.

But based on all this, perhaps we shouldn’t even be using the term “impingement” anyway.

From a non-biomechanical perspective, I’m not even sure we truly understand the etiology of shoulder pain at times and always seem to rush towards a biomechanical “impingement” approach.  There could be numerous reasons why graded exercise can help reduce shoulder pain other than purely biomechanical factors.

But let’s not forget one main point here from this study.  At 5 years down the road, these patients still had shoulder pain between a 1.5 and 3 out of 10 on a visual analog scale.  

So advising people to ignore the biomechanics and simply work through some pain may not be an ideal approach as well.  

I’d hate to see us go down that road.

These patients had shoulder pain for greater than 3 months to be included in this study.  It’s difficult to quantify the degree of rotator cuff pathology present in these people, how this impacted their shoulder function, and what their long term prognosis will be going forward.  There is still underlying inflammation of the rotator cuff.

Image from Wikipedia

So What Should We Do?

As research like this continues to be published, we’re probably going to be seeing less of these procedures.

Maximizing the function of the shoulder is going to become even more important, regardless of whether or not something is causing “impingement.”  

I’ve had a lot of success with people by keeping it simple.  Rather than worry about the exact specifics of the pain, just simply focus on normalizing motion, increasing strength of the rotator cuff and scapular muscles, enhancing dynamic stability, and then gradually building tissue capacity through loading.

This is a great example of when focusing on the functional deficits is more impactful than the structural diagnosis.  

Optimize the person, don’t just treat the pain.

Special Tests for Rotator Cuff Tears

Rotator cuff tears are one of the most common injuries we see in orthopedic physical therapy.

During the clinical examination of the shoulder, we want to perform special tests designed to detect a rotator cuff tear.

Below are my 4 favorite special tests for rotator cuff tears that I perform during my clinical examination of the shoulder.  These 4 tests do a good job detecting larger tears that are causing dysfunction.  If you’re looking for more subtle rotator cuff injuries, I have another article on my shoulder impingement evaluation.

As rotator cuff tears become more common, we are starting to see them in younger and more active patients.  In these patients, they often have smaller tears and it is much more difficult to detect with our special tests.  These types of patients often present with pain and weakness, and not as much dysfunction as you would see in a traditional older patient with a more degenerative tear.

This is likely because their rotator cuff tear is either small or partial.  These are often just isolated to the supraspinatus muscles as well, and their other rotator cuff muscles are functioning well.

As a rotator cuff tear becomes larger, retracted, and more degenerative in nature, the patient’s shoulder dysfunction will become more apparent as it becomes difficult for the rotator cuff as a group to function well.

Shoulder Shrug Sign

The first special test I perform to diagnose a rotator cuff tear is the shoulder shrug sign.

During this test, the key to check if they can actively elevate their arm if you help them past their shrug arc.  When the shoulder is positioned below 90 degrees, the line of pull and the force vector of the deltoid muscles is superior.  This is often counterbalanced by the line of pull and force vector of the rotator cuff.

In the image below, the left is the line of pull of the deltoid at various shoulder positions.  The picture on the right is the supraspinatus. Notice how the deltoid starts to have a similar line of pull as the rotator cuff once the shoulder reaches 90-120 degrees of elevation:

If the rotator cuff is torn, then the deltoid is the dominant muscle and the resultant force vector is more superior.

This is the shrug.

However, one you get the arm overhead, the deltoid is now more in line with the rotator cuff and can help center the humeral head within the glenoid fossa.

So, you want to passively help them get above this position to see if they can elevate towards the upper range of elevation.

There isn’t really any information in the literature regarding this test.  It’s not something you’d probably find as a specific test for a rotator cuff tear, but something I have clinically found to be relevant to me.

Shoulder Drop Arm Test

The next rotator cuff tear special test that I perform is the drop arm test.  The concept of this test is pretty similar to the shrug sign. You passively elevate the arm and see if they can hold that position without the arm dropping, or shrugging.

If the arm drops or shrugs, then the rotator cuff likely isn’t able to counterbalance the superior line of pull of the deltoid.

The research has shown that the sensitivity of the drop arm test is low to moderate, but specificity is high from 80-100%.  This is consistent with most of your clinical examination of the shoulder. You usually have to have a significant tear to start seeing these tests positive.

Rotator Cuff Lag Sign

The rotator cuff lag signs are similar special tests as the drop arm test.  Essentially, they are like a drop arm for external rotation of the shoulder instead of elevation.

As rotator cuff tears get larger, they tend to extend from the supraspinatus into the infraspinatus.  The lag signs show a difficulty in the external rotators holding the arm against gravity.

The test appears to be specific in the literature with specificity between 88-100% and several studies in the 90% range.  Sensitivity has varied in studies, but has shown 45-56% sensitivity to detect full thickness supraspinatus tears, 70% in infraspinatus tears, and 100% in teres minor tears.  This makes sense to me as it’s a better test for larger tears extending into the infraspinatus and teres minor.

Lag Sign at 90 Degrees

I also like to perform a variation of the lag sign at 90 degrees of elevation.  It is the same test as the traditional lag sign, however, I have found this test to be even more challenging.  I have seen patients that had a positive lag sign at 90 degrees of elevation, and a negative lag sign at 20-30 degrees.  It’s simply a more challenging position for the cuff.

The research has shown this to have specificity between 70-100%, however varying sensitivity from 20-100%.  But again, for the same reasons as the lag sign above.

Special Tests for Rotator Cuff Tears

If you use all four of the above special tests as a cluster, I think you’ll often be able to detect a large full thickness rotator cuff tear during your clinical examination.  These tests tend to be more sensitive to larger tears in older and more degenerative patients.

But remember, special tests are just a piece of the puzzle.

Learn Exactly How I Evaluate and Treat the Shoulder

If you are interested in mastering your understanding of the shoulder, I have my acclaiming online program teaching you exactly how I evaluate and treat the shoulder.

mike reinold shoulder seminar

The online program takes you through everything you need to become a shoulder expert. You can learn at your own pace in the comfort of your own home. In addition to shoulder impingement, you’ll learn about:

  • The evaluation of the shoulder
  • Selecting exercises for the shoulder
  • Manual resistance and dynamic stabilization drills for the shoulder
  • Nonoperative and postoperative rehabilitation
  • Rotator cuff injuries
  • Shoulder instability
  • SLAP lesions
  • The stiff shoulder
  • Manual therapy for the shoulder

The program offers CEU hours for physical therapists and athletic trainers. Click below to learn more:

Should We Delay Range of Motion After a Rotator Cuff Repair Surgery?

Over the last several years, there has been a trend among orthopedic surgeons to delay the start of rehabilitation, specifically range of motion exercises, following rotator cuff repair surgery.

It’s my opinion that this trend started in response to the research that has been reported in the past that show issues with tendon healing rates and a large percentage of rotator cuff repairs are not intact at follow up examination.

For example, I previously discussed the outcomes of arthroscopic rotator repairs and noted that at the one year follow up after surgery, 68% had an intact rotator cuff. 32% had a full thickness tear again.

So physicians did what they tend to do… They started to get more conservative and delayed the start of rehabilitation. I’ve discussed a similar to approach to rehabilitation following total shoulder replacement.

But does delaying the start of range of motion after rotator cuff repair surgery even help improve outcomes?

Does immobilization after rotator cuff repair increase tendon healing?

A systematic review was published in the Archives of Orthopaedic and Trauma Surgery that looked at 3 randomized control trials comparing immediate versus delayed range of motion follow rotator cuff repair surgery.

The authors reported a few findings.

Most importantly, there was no difference in tendon healing rate, showing that early range of motion is safe to perform and not the reason why people may retear.

Range of motion improved earlier in the immediate range of motion group, but was similar at the year mark. This is consistent with many past studies. Again physicians read into this and use this stat to favor delayed range of motion, stating that patients are all the same at 1 year postoperative. However, as we all know, restoring motion is key to the patient’s’ subjective and functional outcomes. Similarly, functional outcomes were achieved sooner in the immediate range of motion group.

Based on this systematic review, I would continue to recommend performing control range of motion following rotator cuff repair surgery as it appears to be safe and effective at restoring motion and function sooner than if we delay rehabilitation.

Learn More About How I Evaluate and Treat the Shoulder

I’m pretty excited to announce I have revised my acclaimed online program teaching you exactly how I evaluate and treat the shoulder to now include a lesson on the arthritic shoulder! If you want to learn more about how I work with rotator cuff repairs, and everything else related to the shoulder, you’re going to want to take my online course.

 

Should We Delay Range of Motion After a Total Shoulder Replacement?

Total shoulder replacement surgery is being performed more and more each year.  Our current patients were more active in sports in their youth, potentially increasing the chances of developing an arthritic shoulder.  They also want to remain active as they age, potentially increasing the likelihood that they want to have a total shoulder arthroplasty surgery to allow them to remain active.

Over the years, the surgical technique for a total shoulder replacement has improved, though I’m not sure our rehabilitation approach has also improved.  If our patients are younger and want to be more active after total shoulder replacement, then perhaps our rehabilitation programs should adjust based on their goals.

Rehabilitation Following Total Shoulder Replacement

Historically, a conservative approach was appropriate for many patients, as their needs and activity goals were less aggressive than many patients today.  It was acceptable to have a moderate loss of range of motion in exchange for less pain in their shoulder.

Many surgeons continue to recommend a conservative approach to the restoration of range of motion following surgery.

It is true that one of the primary goals of the postoperative rehabilitation following total shoulder replacement is to protect the subscapularis.  The subscapularis muscle is taken down to some extent during the surgical procedure and the integrity of this muscle has been correlated to the overall outcome of the procedure.

Other motions, such as behind the back and shoulder extension behind their body, also place the arthroplasty in a disadvantageous position and can lead to dislocation of the joint.

But even with these precautions, I am still an advocate of early range of motion, especially if you respect these restrictions.

Passive ROM and Active ROM are Not the Same

A recent report was recently published in Journal of Shoulder and Elbow Surgery that may actually be causing some confusion on when to start range of motion.

In the study, the authors compared a group of patients that began range of motion immediately versus a group that delayed 4 weeks.  The authors reported that the immediate range of motion group gained more motion, restored it earlier, and also showed an earlier increase in functional outcome scores.

However, 96% of the patients that delayed range of motion showed healing of the lesser tuberosity osteotomy, while only 82% of the immediate range of motion group showed healing.  Furthermore, functional outcomes scores 3 months and 1 year after surgery were similar between the groups.

This has led to many recommending a delay in range of motion.  But…

When looking deeper at the methods, the authors chose to use the rope and pulley and stick elevation range of motion exercises.  As we all know, these are not passive range of motion exercises, they are active assisted range of motion exercises.

There’s a big difference between passive and active range of motion exercises!

Previous EMG studies have shown the rotator cuff to be between 18-25% active and the deltoid to be between 21-43% active during these exercises.  Not very passive.  Conversely, passive range of motion exercises have been shown to be between 3-10% active.

This is a big difference.  I believe passive range of motion is appropriate, as long as you respect the restrictions on restoring external rotation to protect the subscapularis and avoid behind the body and behind the back motions to protect the replacement.
Immediate Range of Motion Restores Function Faster

Since we all work with these patients after surgery, we know that they are always happier when they restore their motion sooner.  And this increase in range of motion is likely related to the earlier improvement in functional outcome scores.

I think there is a middle ground of immediate, yet cautious, passive range of motion.  Again, I want to reiterate, “passive” range of motion.  Not active.

By focusing on this, I believe our patients will have much better outcomes.

Learn More About How I Evaluate and Treat the Shoulder

I’m pretty excited to announce I have revised my acclaimed online program teaching you exactly how I evaluate and treat the shoulder to now include a lesson on the arthritic shoulder!  If you want to learn more about how I work with the arthritic shoulder, patients following total and reverse shoulder replacements, and everything else related to the shoulder, you’re going to want to take my online course.

 

Dry Needling for Scapular Winging

This week’s article is a guest post from Michael Infantino.  Michael reached out to me on Facebook and sent me the below videos of a patient’s improvement in scapular winging after dry needling the serratus anterior.

I wanted to share the below article that Michael wrote showing the videos, but also talk about how trigger points may be involved.

I’m not sure what to make of these videos, if trigger points are involved, or exactly how dry needling the serratus anterior helped this patient’s winging.  But I am sure that I was impressed with the results.  I wish we knew more about the reasoning and mechanism, but in the meantime I’m happy we can help people feel and move better.

Dry Needling for Scapular Winging

Can we correct scapular winging in a matter of minutes?  This obviously depends on the cause of the scapular winging.

It is well documented that injury to the long thoracic nerve or cervical spine may lead to medial border scapular winging or dyskinesia of the scapula (Meininger, 2011). These are always challenging.  Ruling out neuromuscular cause can be done with a nerve conduction velocity test or EMG.  

But a recent patient of mine, made me think…

Research has continually shown that muscles with trigger points demonstrate the following:

  • Altered muscle activation patterns on EMG (Lucas, 2010; Wadsworth, 1997)
  • Reduced muscle strength (Celik, 2011)
  • Accelerated muscle fatigue (Ge, 2012)
  • Reduced antagonist muscle inhibition (Ibarra, 2011)  
  • Increased number of trigger points on the painful side (Alburquerque-Sendin, 2013; Bron, 2011; Fernandez-de-las-Penas, 2012; Ge, 2006; Ge, 2008)

Appreciating these findings would lead most to conclude that treatment of trigger points could improve scapular mobility and timing. This was my immediate thought when I noticed a significant medial border scapular winging while watching my patient raise and lower his arm.

It wasn’t until I read this research that I began using dry needling to do more than just manage pain. The results seen following dry needling to the serratus anterior were remarkable.

After seeing this amount of scapular winging, I dry needled his serratus anterior muscle.  Note the remarkable improvement:

How Trigger Point Dry Needling May Impact Scapular Winging

It is well documented that appropriate muscle activation patterns (MAP) surrounding the shoulder is necessary for efficient and pain free mobility (Lucas, 2003). Lucas and group actually gauged the effect of trigger point dry needling on MAP in subjects with latent trigger points (LTrP).

“Latent myofascial trigger points (LTrPs) are pain free neuromuscular lesions that are associated with muscle overload and decreased contractile efficiency” (Simons et al., 1999, p. 12). MAP’s of the upper trapezius, serratus anterior, lower trapezius, infraspinatous and middle deltoid were compared in a group with LTrP’s and one without. Following surface EMG, the LTrP’s were treated with trigger point dry needling. Surface EMG was performed after treatment as well.

Findings from this study were as follows:

  • Muscle activation of the upper trapezius in the LTrP group pre-treatment.
  • Early activation of the infraspinatous in the LTrP group pre-treatment.
  • Increased variability of muscle activation in all muscles assessed in the LTrP group pre-treatment compared to the control group.  
  • Altered MAP of distal musculature (infraspinatous and middle deltoid) were consistent with co-contraction, a finding that has been attributed to increased muscle fatigability (Chabran et al., 2002).
  • Improved muscle activation times in the LTrP group following dry needling.
  • Significant decrease in the variability of muscle activation in the LTrP group following dry needling, except for the serratus anterior.
  • The serratus anterior and lower trapezius showed increased variability in both the control and LTrP group, which may be why the results did not reach significance. This is also consistent with the latest research in JOSPT that found dyskinesia to be normal in asymptomatic populations. (Plummer, 2017).

Based on the both my clinical experiences and the research presented in this paper, it would seem highly valuable to focus on the treatment of trigger points to restore muscle activation patterns surrounding the shoulder complex.

Being able to press the “reset button” on a muscle is important for re-establishing normal muscle activation patterns prior to exercise. Inclusion of other manual therapy and exercise techniques is important for optimizing function of the local musculature (range of motion, hypertrophy, strength and endurance).

No research that I am familiar with has compared dry needling to other manual therapy techniques for restoring MAP in muscles adjacent to the shoulder. Future research that compares various trigger point treatments for restoration of normal MAP would be beneficial.

 

About the Author

Dr. Michael Infantino, DPT, is a physical therapist who works with active military members in the DMV region. You can find more articles by Michael at RehabRenegade.com.

References

  • Alburquerque-Sendin, F., Camargo, P.R., Vieira, A., Salvini, T.F., 2013. Bilateral myofascial trigger points and pressure pain thresholds in the shoulder muscles in patients with unilateral shoulder impingement syndrome: a blinded, controlled study. Clin. J. Pain 29 (6), 478e486.
  • Bron, C., de Gast, A., Dommerholt, J., Stegenga, B., Wensing, M., Oostendorp, R.A., 2011a. Treatment of myofascial trigger points in patients with chronic shoulder pain: a randomized, controlled trial. BMC Med. 9, 8.
  • Chabran, E., Maton, B., Fourment, A., 2002. Effects of postural muscle fatigue on the relation between segmental posture and movement. Journal of Electromyography and Kinesiology 12, 67–79.
  • Celik, D., Yeldan, I., 2011. The relationship between latent trigger point and muscle strength in healthy subjects: a double-blind study. J. Back Musculoskelet. Rehabil. 24 (4), 251e256.
  • Cummings, T.M., White, A.R., 2001. Needling therapies in the management if myofascial trigger point pain: a systematic review. Archives of Physical and Medicine and Rehabilitation 82, 986–992.
  • Ge, H.Y., Arendt-Nielsen, L., Madeleine, P., 2012. Accelerated muscle fatigability of latent myofascial trigger points in humans. Pain Med. 13 (7), 957e964.
  • Ge, H.Y., Fernandez-de-las-Penas, C., Arendt-Nielsen, L., 2006. Sympathetic facilitation of hyperalgesia evoked from myofas- cial tender and trigger points in patients with unilateral shoul- der pain. Clin. Neurophysiol. 117 (7), 1545e1550.
  • Ge, H.Y., Fernandez-de-Las-Penas, C., Madeleine, P., Arendt- Nielsen, L., 2008. Topographical mapping and mechanical pain sensitivity of myofascial trigger points in the infraspinatus muscle. Eur. J. Pain 12 (7), 859e865.
  • Hillary A. Plummer, Jonathan C. Sum, Federico Pozzi, Rini Varghese, Lori A. Michener. Observational Scapular Dyskinesis: Known-Groups Validity in Patients With and Without Shoulder Pain. J Orthop Sports Phys Ther:1-25.  
  • Ibarra, J.M., Ge, H.Y., Wang, C., Martinez Vizcaino, V., Graven- Nielsen, T., Arendt-Nielsen, L., 2011. Latent myofascial trigger points are associated with an increased antagonistic muscle activity during agonist muscle contraction. J. Pain 12 (12), 1282e1288.
  • Lucas KR, Polus BI, Rich PS. Latent myofascial trigger points: their effects on muscle activation and movement efficiency. J Bodyw Mov Ther. 2004;8:160-166Lucas KR, Polus BI, Rich PS. Latent myofascial trigger points: their effects on muscle activation and movement efficiency. J Bodyw Mov Ther. 2004;8:160-166
  • Lucas KR, Polus BI, Rich PS. Latent myofascial trigger points: their effects on muscle activation and movement efficiency. J Bodyw Mov Ther. 2004;8:160-166Meininger, A.K., Figuerres, B.F., & Goldberg, B.A. (2011). Scapular winging: an update. The journal of The American Academy of Orthopaedic Surgeons, 19(8), 453-462.
  • Simons, D.G., Travell, J.G., Simons, L.S., 1999. The Trigger Point Manual, Vol 1, 2nd Edition. Williams and Wilkins, Baltimore, USA.
  • Wadsworth, D.J.S., Bullock-Saxton, J.E., 1997. Recruitment patterns of the scapular rotator muscles in freestyle swimmers with subacromial impingement. International Journal Sports Medicine 18, 618–624.

 

6 Keys to Shoulder Instability Rehabilitation

Shoulder instability is a common pathology encountered in the orthopedic and sports medicine setting.

But “shoulder instability” itself isn’t that simple to understand.

Would you treat a high school baseball player that feels like their shoulder is loose when throwing the same as a 35 year old that fell on ice onto an outstretched arm and dislocated their shoulder?  They’re both “shoulder instability,” right?

There exists a wide range of symptomatic shoulder instabilities from subtle recurrent subluxations to traumatic dislocations. Nonoperative rehabilitation is commonly utilized for shoulder instability to regain previous functional activities through specific strengthening exercises, dynamic stabilization drills, neuromuscular training, proprioception drills, scapular muscle strengthening program and a gradual return to their desired activities.

I’ve had great success rehabilitating dislocated shoulders and helping people return back to full activities without surgery.  But to truly understand shoulder instability, there are several key factors that you must consider.

 

Key Factors When Designing Rehabilitation Programs for Shoulder Instability

Because there are so many different variations of shoulder instability, it is extremely important to understand several factors that will impact the rehabilitation program.  This will allow us to individualize programs and enhance recovery.

There are 6 main factors that I consider when designing my rehabilitation programs for nonoperative shoulder instability rehabilitation.  I’m going to cover each in detail.

 

Factor #1 – Chronicity of Shoulder Instability

The first factor to consider in the rehabilitation of a patient with shoulder instability is the onset of the pathology.

Pathological shoulder instability may result from an acute, traumatic event or chronic, recurrent instability. The goal of the rehabilitation program may vary greatly based on the onset and mechanism of injury.

Following a traumatic subluxation or dislocation, the patient typically presents with significant tissue trauma, pain and apprehension. The patient who has sustained a dislocation often exhibits more pain due to muscle spasm than a patient who has subluxed their shoulder. Furthermore, a first time episode of dislocation is generally more painful than the repeat event.

Rehabilitation will be progressed based on the patient’s symptoms with emphasis on early controlled range of motion, reduction of muscle spasms and guarding and relief of pain.

The primary traumatic dislocation is most often treated conservatively with immobilization in a sling and early controlled passive range of motion (ROM) exercises especially with first time dislocations. The incidence of recurrent dislocation ranges from 17-96% with a mean of 67% in patient populations between the ages of 21-30 years old. Therefore, the rehabilitation program should progress cautiously in young athletic individuals. It should be noted that Hovelius et al has demonstrated that the rate of recurrent dislocations is based on the patient’s age and not affected by the length of post-injury immobilization. Individuals between the ages of 19 and 29 years are the most likely to experience multiple episodes of instability. Hovelius et al also noted patients in their 20’s exhibited a recurrence rate of 60% whereas patients in their 30’s to 40’s had less than a 20% recurrence rate. In adolescents, the recurrence rate is as high as 92% and 100% with an open physes.

Conversely, a patient presenting with atraumatic instability often presents with a history of repetitive injuries and symptomatic complaints. Often the patient does not complain of a single instability episode but rather a feeling of shoulder laxity or an inability to perform specific tasks.

Rehabilitation for this patient should focus on early proprioception training, dynamic stabilization drills, neuromuscular control, scapular muscle exercises and muscle strengthening exercises to enhance dynamic stability due to the unique characteristic of excessive capsular laxity and capsular redundancy in this type of patient.

Chronic subluxations, as seen in the atraumatic, unstable shoulder may be treated more aggressively due to the lack of acute tissue damage and less muscular guarding and inflammation. Rotator cuff and periscapular strengthening activities should be initiated while ROM exercises are progressed. Caution is placed on avoiding excessive stretching of the joint capsule through aggressive ROM activities.

The goal is to enhance strength, proprioception, dynamic stability and neuromuscular control especially in the specific points of motion or direction which results in instability complaints.

 

Factor #2 – Degree of Shoulder Instability

Bankart LesionThe second factor is the degree of instability present in the patient and its effect on their function.

Varying degrees of shoulder instability exist such as a subtle subluxation or gross instability. The term subluxation refers to the complete separation of the articular surfaces with spontaneous reduction. Conversely, a dislocation is a complete separation of the articular surfaces and requires a specific movement or manual reduction to relocate the joint. This will result in underlying capsular tissue trauma. Thus, with shoulder dislocations the degree of trauma to the glenohumeral joint’s soft tissue is much more extensive.

Speer et al have reported that in order for a shoulder dislocation to occur, a Bankart lesion must be present and also soft tissue trauma must be present on both sides of the glenohumeral joint capsule.

Thus, in the situation of an acute traumatic dislocation, the anterior capsule may be avulsed off the glenoid (this is called a Bankart lesion – see pictures to the right) and the posterior capsule may be stretched, allowing the humeral head to dislocate. This has been referred to as the “circle stability concept.”

The rate of progression will vary based upon the degree of instability and persistence of symptoms. For example, a patient with mild subluxations and muscle guarding may initially tolerate strengthening exercises and neuromuscular control drills more than a patient with a significant amount of muscular guarding.

 

Factor #3 – Concomitant Pathology

Hill Sachs LesionThe third factor involves considering other tissues that may have been affected and the premorbid status of the tissue.

As we previously discussed, disruption of the anterior capsulolabral complex from the glenoid commonly occurs during a traumatic injury resulting in an anterior Bankart lesion. But other tissues may also be involved.

Often osseous lesions may be present such as a concomitant Hill Sach’s lesion caused by an impaction of the posterolateral aspect of the humeral head as it compresses against the anterior glenoid rim during relocation. This has been reported in up to 80% of dislocations. Conversely, a reverse Hill Sach’s lesion may be present on the anterior aspect of the humeral head due to a posterior dislocation.

Occasionally, a bone bruise may be present in individuals who have sustained a shoulder dislocation as well as pathology to the rotator cuff. In rare cases of extreme trauma, the brachial plexus may become involved as well. Other common injuries in the unstable shoulder may involve the superior labrum (SLAP lesion) such as a type V SLAP lesion characterized by a Bankart lesion of the anterior capsule extending into the anterior superior labrum. These concomitant lesions will affect the rehabilitation significantly in order to protect the healing tissue.

 

 

Factor # 4 – Direction of Shoulder Instability

Shoulder Multidirectional InstabilityThe next factor to consider is the direction of shoulder instability present. The three most common forms include anterior, posterior and multidirectional.

Anterior shoulder instability is the most common traumatic type of instability seen in the general orthopedic population. It has been reported that this type of instability represents approximately 95% of all traumatic shoulder instabilities. However, the incidence of posterior instabilities appears to be dependent on the patient population. For example, in professional or collegiate football, the incidence of posterior shoulder instability appears higher than the general population. This is especially true in linemen. Often, these posterior instability patients require surgery as Mair et al reported 75% required surgical stabilization.

Following a traumatic event in which the humeral head is forced into extremes of abduction and external rotation, or horizontal abduction, the glenolabral complex and capsule may become detached from the glenoid rim resulting in anterior instability, or a Bankart lesion as discussed above.

Conversely, rarely will a patient with atraumatic instability due to capsular redundancy dislocate their shoulder. These individuals are more likely to repeatedly sublux the joint without complete separation of the humerus from the glenoid rim.

Posterior shoulder instability occurs less frequently, only accounting for less than 5% of traumatic shoulder dislocations.

This type of instability is often seen following a traumatic event such as falling onto an outstretched hand or from a pushing mechanism. However, patients with significant atraumatic laxity may complain of posterior instability especially with shoulder elevation, horizontal adduction and excessive internal rotation due to the strain placed on the posterior capsule in these positions.

Multidirectional instability (MDI) can be identified as shoulder instability in more than one plane of motion. Patients with MDI have a congenital predisposition and exhibit ligamentous laxity due to excessive collagen elasticity of the capsule.

Shoulder Sulcus SignOne of the most simple tests you can perform to assess MDI is the sulcus sign.

I would consider an inferior displacement of greater than 8-10mm during the sulcus maneuver with the arm adducted to the side as significant hypermobility, thus suggesting significant congenital laxity.  You can see this pretty good in this photo to the right, the sulcus is clearly larger than my finger width.

Due to the atraumatic mechanism and lack of acute tissue damage with MDI, ROM is often normal to excessive.

Patients with recurrent shoulder instability due to MDI generally have weakness in the rotator cuff, deltoid and scapular stabilizers with poor dynamic stabilization and inadequate static stabilizers. Initially, the focus is on maximizing dynamic stability, scapula positioning, proprioception and improving neuromuscular control in mid ROM.

Also, rehabilitation should focus on improving the efficiency and effectiveness of glenohumeral joint force couples through co-contraction exercises, rhythmic stabilization and neuromuscular control drills. Isotonic strengthening exercises for the rotator cuff, deltoid and scapular muscles are also emphasized to enhance dynamic stability.

 

Factor #5 – Neuromuscular Control

neuromuscular controlThe fifth factor to consider is the patient’s level of neuromuscular control, particularly at end range.

Injury with resultant insufficient neuromuscular control could result in deleterious effects to the patient. As a result, the humeral head may not center itself within the glenoid, thereby compromising the surrounding static stabilizers. The patient with poor neuromuscular control may exhibit excessive humeral head migration with the potential for injury, an inflammatory response, and reflexive inhibition of the dynamic stabilizers.

Several authors have reported that neuromuscular control of the glenohumeral joint may be negatively affected by joint instability.

Lephart et al compared the ability to detect passive motion and the ability to reproduce joint positions in normal, unstable and surgically repaired shoulders. The authors reported a significant decrease in proprioception and kinesthesia in the shoulders with instability when compared to both normal shoulders and shoulders undergoing surgical stabilization procedures.

Smith and Brunoli reported a significant decrease in proprioception following a shoulder dislocation.

Blasier et al reported that individuals with significant capsular laxity exhibited a decrease in proprioception compared to patients with normal laxity.

Zuckerman et al noted that proprioception is affected by the patient’s age with older subjects exhibiting diminished proprioception than a comparably younger population.

Thus, the patient presenting with traumatic or acquired instability may present with poor neuromuscular control that must be addressed.

 

Factor # 6 – Pre-Injury Activity Level

The final factor to consider in the nonoperative rehabilitation of the unstable shoulder is the arm dominance and the desired activity level of the patient.

If the patient frequently performs an overhead motion or sporting activities such as a tennis, volleyball or a throwing sport, then the rehabilitation program should include sport specific dynamic stabilization exercises, neuromuscular control drills and plyometric exercises in the overhead position once full, pain free ROM and adequate strength has been achieved.

Patients whose functional demands involve below shoulder level activities will follow a progressive exercise program to return full ROM and strength. The success rates of patients returning to overhead sports after a traumatic dislocation of their dominant arm are often low, but possible.

Arm dominance can also significantly influence the successful outcome. The recurrence rates of instabilities vary based on age, activity level and arm dominance. In athletes involved in collision sports, the recurrence rates have been reported between 86-94%.

 

Keys to Shoulder Instability Rehabilitation

To summarize, nonoperative rehabilitation of shoulder instability has many subtle variations.  To simplify my thought process, I always think of these 6 key factors before I decide what I want to do.  I hope these factors help you too.  What other factors do you consider when designing rehabilitation programs for shoulder instability?

 

Learn How I Evaluate and Treat the Shoulder

shoulder seminarWant to learn exactly how I rehabilitate shoulder instability?

I have a whole lesson on this as part of my comprehensive online program on the Evidence Based Evaluation and Treatment of the Shoulder at ShoulderSeminar.com.  If you want to learn exactly how I evaluate and treat the shoulder, including shoulder instability, this course is for you.  You’ll be an expert on shoulders!