Shoulder Pain – Recent research, concepts & new ideas

Introduction

Firstly, I must apologise for the time it has taken for me to get this blog out! It has been down to a number of factors including the birth of my daughter and a lot to do with the amount of reading and research required to tackle this subject.

It is no secret that anatomically the shoulder joint is one of the most complex. It’s also very unique; the range of movement and functional freedom the shoulder joint gives us is one not many other animals share. It’s this freedom and range that not only helps us, but in many cases why we may develop undesirable symptoms.

There are many questions surrounding the assessment and treatment of the shoulder, particularly over recent years but, as in my last blog I shall be standing on the shoulders (excuse the pun) of giants to tackle them. You cannot mention the shoulder, whether it be pathology, injury, assessment or treatment without Jeremy Lewis in the same breath. He has contributed immensely over the last decade to bring us research and clinically applicable ideas. I will also discuss ideas from the great Jo Gibson (@shouldergeek1), many of you will have heard her numerous fantastic podcast appearances, if not here’s a link to a great podcast with Jack Chew (@Chews_Health) and Jo: https://chewshealth.co.uk/tpmpsession20/ or with David Pope (@davidkpope) at the Clinical Edge Podcast (https://www.clinicaledge.co/podcast/physio-edge-podcast/physio-edge-043-sporting-shoulder-with-jo-gibson). I will admit from the off, a lot of the concepts and ideas I use in my own practice have been unashamedly stolen from these great therapists, so, sorry guys, it’s too good to ignore!

I will also be drawing on my 6 year plus experience of being in professional rugby, where the shoulder joint (as you can imagine) is placed under enormous stresses on a daily basis. During this time my understanding of the anatomy and management of a shoulder from surgery to return to sport has improved immensely with advice from the excellent Mr Richard Evans (https://www.spirehealthcare.com/cardiff/our-facilities-treatments-and-consultants/our-consultants/mr-richard-o-n-evans/). In sport and in particular the rugby shoulder, experience clinically and with regards to research doesn’t get better than Dr. Ian Horsely (@Back_in_Action). Personally having working in rugby for the past 6 years his work on the rugby shoulder has helped my understanding and has guided my practice significantly.

So the plan for this blog will follow in suit from my previous hamstring addition. We will discuss:

• Anatomy of the shoulder
• Pathology (and terminology) of rotator cuff related shoulder pain
• Subsequent shoulder assessment
• Treatment of rotator cuff related pain

Sounds easy doesn’t it! Here goes!

Anatomy

This is what really excites me about the shoulder. The shoulder has been a huge part of our evolutionary journey, it contributes to how and why we have become the most dominant species on the planet. Aside from the development of the human brain (no big deal or anything) it is likely that the shoulder played a significant part in our species’ rise to the top, and it’s all down to the anatomy! A recent study performed in Harvard whose researchers compared the shoulder blades of us to our African ape ancestors discovered that modern human shoulders most similarly resemble the orangutans' lateral orientation and the African apes' blade shape.

"These changes in the shoulder, which were probably initially driven by the use of tools well back into human evolution, also made us great throwers," Neil T. Roach, a fellow of human evolutionary biology at Harvard University, said. "Our unique throwing ability likely helped our ancestors hunt and protect themselves, turning our species into the most dominant predators on earth."

So it was our ability to throw effectively that made us great hunters as well as the ability to use those newly formed big brains of ours to build and use tools.

But how does our anatomy allow this large range of movement and how it is advantageous? The anatomy of the shoulder joint compared to other joints in the body is relatively complex but let’s try and break it down. Let’s discuss it in the following order and try and make some sense of it all:

• Bone (and therefore the joints of the shoulder)
• Ligaments (Glenohumeral Joint (Ball & Socket) - GHJ)
• Labrum (re: GHJ)
• Bursa (re: GHJ)
• Muscle (re: GHJ)

So the shoulder is made up of 3 boney structures and 3 (arguably 4, we’ll discuss this later) joints. The scapula (shoulder blade), the clavicle (collar bone) and the humerus (aka funny bone…humerus…funny..get it?) are the 3 bones involved (see image 1). These bones comprise the shoulder ‘joints. Namely the Sternoclavicular Joint (SCJ) which is where the sternum meets the clavicle, the Acromiclavicular Joint (ACJ), where the acromion (a bone part of the scapular) meets the clavicle and the Glenohumeral Joint (GHJ). This is where the humerus attaches to the appendicular skeleton into the glenoid (a shallow socket formed by the scapular).  

Somewhat controversially there is a 4th joint sometimes discussed, the Scapulothoracic Joint (STJ). This is with regards to the relationship between the scapular and the thoracic region. We won’t go into the detail of each joint in this piece (we have enough to discuss already!). We will predominantly be concerned about the GHJ and its relationship with the musculature surrounding the shoulder, however it is important to note the anatomy and function of all the joints when considering a rehab programme.

The Glenohumeral Ligaments can be split into 3 different parts, the superior GHL, the middle GHL and the inferior GHL. Each of these separate ligaments have different characteristics which have been best classified since the advent of arthroscopic surgery. The ligaments are much easier to see from the inside than out!

So excuse the following paragraph as this is mainly aimed at clinicians and is a bit more wordy than usual. The important thing to note about the ligaments is that they add the main aspect of stability to the shoulder joint. The superior GHL can be found above the subscapularis recess and is sometimes obscured from view on arthroscopy by the long head of biceps tendon. The middle GHL can be thin in some people and thick in others, what is consistent however is its position, it crosses obliquely down across the subscapularis bursa. The inferior GHL can be considered as the most important in terms of stability and forms a hammock like arrangement between the scapular and the humerus. When together the ligaments for a water tight sac which is known as the ‘joint capsule’.

So we know now that the ligaments provide stability to the shoulder, but they don’t do this on their own. The shoulder labrum is another important factor in increasing the stability we have. You have likely heard the shoulder referred to as a ‘ball and socket’ joint which is of course correct. It turns out though, that on its own the ball is rather large and the socket is small. The humeral head (the ball) is approximately 1/3 bigger than the glenoid fossa (the socket). While this allows for a large range of motion it doesn’t provide stability. This is where the labrum comes in. It acts as an extension to this shallow fossa providing a ‘suction cup’ like effect. The labrum is predominately a fibrous cartilaginous tissue much like the meniscus in your knee. Dislocation of the shoulder often leads to a disruption of the labrum which can increase the instability. There are some common labrum ruptures that I would like to mention, namely a SLAP (Superior Labrum anterior to posterior – pictured below) lesion, which usual occurs where the long head of biceps tendon anchors to the labrum.

A Bankarts lesion which occurs between 3 and 6 o’clock on the labrum, a reverse Bankarts which occurs between 6 and 9 o’clock and a combination of all of the above in severe cases is known as a 270 degrees tear.  Trauma as a cause of instability can be classified as a ‘Type I’ under the Stanmore classification. All in all the ligaments and the labrum contribute as connective tissue stabilisers of the shoulder. However, with reference to the Stanmore classification, fully intact ligaments and labrum do not always = a stable, pain free shoulder. It is the integration of these connective tissues with the dynamic system of the rotator cuff that ultimately provides dynamic stability at the GHjt, that is; keeping our shoulders in the socket and moving within a full, pain free range of motion.

So, what are these infamous Rotator Cuff muscles? What do they do? And why are they so important? Simply put the Rotator Cuff muscles are the muscles around the shoulder that control movement. There are 4 in total. The Subscapularis, the Infraspinatus, the Supraspinatus and the Teres Minor.

The subscapularis medially rotates the humerus while the infraspinatus, supraspinatus and teres minor lateral rotate the humerus. Their function and creation of medial and lateral torque on the humerus is important to note as it will influence both assessment of the shoulder joint as well as exercise prescription in rehab. This provision of movement at the shoulder is also contributing its stability. The medial and lateral pull of the shoulder will control the humeral head translation either anteriorly (forward) or posteriorly (backwards). This being the case means the RC is hugely important along with the ligaments and labrum in providing the shoulder a stable base for movement. It was only in recent research that we (when I say we I mean the profession, I can say honestly and without doubt I had no contribution, at all!) discovered the translation of the humeral head during different shoulder movements. It was largely believed prior to this research that the RC contributed to pulling the humeral head into the glenoid fossa preventing any translation or ’movement’.

Why do I get pain?

It has been believed for a long time that the cause of pain was irritation of the acromion above the RC. Particularly by Neer who researched the area heavily, he thought that a closing of the subacromial space caused the acromion to irritate the inferior RC, hence the widely used terminology of ‘Subacromial Impingement’ or ‘Impingement’. The failure to treat this non-surgically then normally lead to an acromioplasty operation, with the view that removing part of the acromion will reduce the irritation of the cuff, increase subacromial space and therefore, reduce pain.

We now know from the research that there are a multitude of things that can contribute to shoulder pain, and that Neer’s previous theory of a closing down of the subacromial space is not the likely driver of pain. Jeremy Lewis in a recently published paper this year reported:

 

“Although numerous factors including; genetics (Harvie et al., 2004), hormonal influences (Magnusson et al., 2007), lifestyle factors such as smoking (Baumgarten et al., 2010) alcohol consumption (Passaretti et al., 2015), comorbidities and level of education (Dunn et al., 2014), biochemical, patho-anatomical, peripheral and central sensitisation, sensory-motor cortex changes (Lewis et al., 2015) and a raft of psychosocial factors (Dean and S€oderlund, 2015) have the potential to contribute to RCRSP, excessive and mal-adaptive load imposed on the tissues appears to be a major influence (McCreesh and Lewis, 2013; Cook et al., 2015)”

 

And that…..

 

“The relevance of the acromion to the development of symptoms and RC tears also remains uncertain. The argument that acromial irritation leads to RC pathology is not supported by observational studies. Payne et al. (1997) reported 91% (39/43) of RC tears occurred on the inferior (articular or joint) side of the tendon with only 9% (n = 4) occurring on the bursal side (i.e. the side under the acromion)”

 

A recent study from D. Wylie & T. Sutor (Feb 2016) has also noted that mental health has a stronger association with patient reported shoulder pain and function than tear size in patients with a full thickness rotator cuff tear.

 

So we now know that the likely driver of pain is number one the mal-adaptive load placed on the tissues, in conjunction with how the patient perceives their own pain and function. These findings overwhelmingly point to the need for a modification to our traditional method of assessment and diagnosis of shoulder pain. We need to take into consideration all of the patients issues both structural and otherwise as well as ditching our old special (or not so special tests) for a more meaningful was of assessing someone’s dysfunction. If only such a thing existed? Luckily people much smarter than me are ahead of the game!

 

Assessment & Rehab – Exercise Selection

Here we are, finally at the good stuff! How do we actually begin to get your shoulder pain free again? In my practice recently, and I’m sure many other physios’ I have adopted the approach of shoulder symptom modification system developed by Jeremy Lewis as well as a big influence from Jo Gibson. In this section I will try and summarise how I approach the assessment, subsequent treatment and exercise selection for patients, using the influence of other therapists and my own idea’s developed from the research.

Assessment

Communication! Communication! Communication! This is THE most important element of, not only the assessment of the shoulder but physiotherapy in general. Patient therapist communication is another blog on its own so I won’t go too much into detail, but I cannot emphasise how important this is for a patient, as well as its ability to lead the therapist down the correct rehab path. I like to keep things as simple as possible with assessments so nearly all my assessments of any joint follow the same order (with sub-points identifying what I am looking for), and I apologise in advance for this section being more focused toward the therapist rather than the patient:

• Full subjective history

Traumatic / Atraumatic (SLAP / RC tear?)

Constant ache / pain lying on the side (Bursal involvement?)

• Surface anatomy observations / palpation

ACJ Pain / Bruising / Step Sign (ACJ)/ Sulcus of the GHJ / Muscular Atrophy

• Range of movement

Stiffness (GIRD / Neutral IR (within 70% of uninjured)) / EOR flexion / EOR ER / HBB

• Strength

ER in neutral / IR in neutral / Reverse throw

• Special (or not so special) tests (only if suspected traumatic injury)

Combination of O’Brien’s / Speed’s / Yurgenson’s / Apprehension Relocation

If all positive – possibility of SLAP tear

• Shoulder Symptom Modification: Does the pain reduce with….

Increasing thoracic extension / flexion

Flexion with External / Internal Rotation load

Scapular Assistance in Flexion / Abduction

Humeral Distraction

Humeral compression

Compressive loads with humeral anterior and posterior distraction

Making a fist (increasing Rotator Cuff activity)

Cervical lateral glides

Before even looking at the shoulder of a patient the establishment of a detailed history is paramount. If trauma is apparent in the history with regards to rotator cuff tear or SLAP lesion it tells me that the patient will respond well to early surgery. The same injuries without trauma will not respond as well to surgery. So before you even start the assessment a clear patient history is a must.

Manual Therapy

Following the assessment, what I then do with the patient very much depends on what is found. I want to start by discussing the infamous manual therapy. I say infamous as I feel manual therapy over the last few years has gotten and is getting a bit of a bad rap. Research hasn’t been too flattering on the subjecting terms of its long term benefits for patients. However, having worked in professional sport and with many private patients I want to tell you why I think it can still be used effectively by therapists.

The fear with any manual therapy is that it is being used passively, giving no real structural benefit to the patient developing a ‘crutch’ for the patient t lean on. A term coined by Mike Stewart which I really like is being a F.I.A.T physio (Fix It Again Thanks!). This is where manual therapy really isn’t useful to the therapist or patient. It is here that communication becomes hugely important! It is paramount that the patient full understands why you are doing manual work. The way I describe this to patients is the manual therapy is used to facilitate their ability to perform exercise. So at the shoulder I may do some lateral cervical spine glides at C5/6, which has been shown to improve the Pain-Pressure Threshold of the upper limb, improve rotator cuff (RC) strength and reduce RC stiffness. Distraction techniques while fixing the scapular may also aid in improve shoulder ROM and therefore allow the RC to work through their full range of movement (ROM). A low cross-adduction stretch may help localise the stretch to the posterior-superior aspect of the cuff. A more detailed explanation of these manual therapy techniques can be heard on the Clinical Edge Podcast with David Pope and Jo Gibson. While doing manual therapy it also provides some more time to talk to your patient to possibly establish a more detailed history or what their expectations are around rehab and return to play in an athlete.

Having worked in professional sport it is also a fact that players / individuals like treatment! They like to interact with their therapist and feel they are as prepared as possible for an event / match. Within a sporting context and an everyday population, you cannot underestimate the psychological aspect of recovery. If you know as a therapist the patient or player is getting all the correct interventions, in my opinion you can perform manual therapy with a clear conscience, knowing the patient or player is receiving what they need physically and psychologically to recover.

As the great Forest Gump once said …that’s all I have to say about that …

Rehab & Adjuncts

The correct exercise selection and rehab is essential in effective treatment of shoulder pathology. This is why I really like the shoulder symptoms modification process of assessment as it really aids in exercise selection for your rehab. For example, if pain is reduced with flexion and external rotation load you know as a starting point you can start to load the posterior rotator cuff, 1 to gain pain relief and 2 to affect a permanent change at the joint. Although not as well researched in the upper limb as the lower limb (see research by Jill Cook and Ebony Rio), I have found some really good early pain relief in the shoulder with isometrics. I’ve found whether trying to reduce pain using internal or external rotation, isometrics are a good starting point. I would follow a similar process of strengthening as outlined in my previous blog regarding the hamstring:

Isometric > eccentric > concentric

This is in conjunction with any range of movement / stretching exercises you may want to incorporate at the thoracic spine and shoulder itself and the shoulder should always be worked through its full range of motion in a direction specific manner. By direction specific I mean what is its functional role? Is the range of movement you are taking the shoulder through relevant to the task that is required of it?

There are far too many exercises to go through in one blog in terms of specifics but I will say as you progress through your rehab it is important to work through the entire kinetic chain. About 20% of shoulder strength comes locally at the shoulder itself, 30% from the trunk and more about 50% of shoulder strength comes from below the waist! Strengthening the shoulder during functional movements is essential in maximising the strength gains you can make, especially with regards to return to sport! We have to remember that movement is ordered functionally not anatomically in the motor cortex. Working muscles in isolation is not maximising your exercise selection effectiveness. Exercises like these below which integrate the kinetic chain whilst improving sensorimotor input, range of movement and correct muscle recruitment patterns are essential in a successful rehab programme of the shoulder:

 

                                

 

 

 

 

 

 

Improving sensorimotor input of the shoulder can be really useful in patients who may display an element of instability due to lack of rotator cuff strength. This is where as well as your exercise selection (which should include resistance, isometrics, weight bearing and elements of proprioception), you can use other adjunct’s such as tape or compression clothing.

With rehab always remember:

• ROM
• Strength
• Proprioception
• Muscle recruitment patterns

 

Conclusion

We made it! If you’ve made it this far well done, and a huge a thank you! Let’s summarize what’s been discussed so far:

• Know your anatomy! This is essential in any aspect of physio but here more than most.
• Place a heavy emphasis on the subjective history. It should lead your assessment and treatment. There are nearly always clues as to what may have caused someone’s pain. Be as thorough as possible, effective communication is essential.
• Don’t always blame the tendon! The driving factor behind the cause of pain can’t all be pinned on our poor tendons!
• In your objective examination special tests aren’t that special
• Move away from a purely structural view point, the biopsychosocial model is the way to go!
• Manual therapy can be beneficial!
• The shoulder symptom modification testing gives you an excellent starting point for rehab as well as a good idea as to the cause of pain.  
• Don’t forget to incorporate the kinetic chain into your rehab programme
• Movement is ordered functionally not anatomically in the motor cortex

 

Thank you so much for taking the time to read this particularly long blog! Please leave some feedback if you have the time, whether that’s in a comment below or sending me a message.

Suggestions about what to do next are welcomed!

Thanks again,

Ash James