Have you heard of the Rotator cuff? If you have shoulder pain you probably have.
Today we are going to go deep into everything you need to know about Rotator cuff injury.
What is the rotator cuff?
Firstly, we need to explain a little about the anatomy of the Rotator cuff before we can discuss Rotator cuff injury.
The Rotator cuff is a group of muscles and their tendons surrounding the shoulder joint:
Supraspinous fossa of scapula to the greater tubercle of the humerus
Assists deltoid in abduction of the humerus
Infraspinous fossa of scapula to the greater tubercle of the humerus
Externally rotates the humerus
The lateral border of the scapula to Greater tubercle of the humerus
Externally rotates the humerus
Subscapular fossa of the scapula to the lesser tubercle of the humerus
Internally rotates the humerus
However, these basic actions that are what these muscles would do in a vacuum and in real life they don’t really work like this. The Rotator cuff works together as a unit to do something very different!
So what does the rotator cuff actually do?
It works in synchronicity to aid the movement of the glenohumeral joint (shoulder joint)
Compression of the humerus on the glenoid (keeping it tight in the socket)
Centring the humerus on the glenoid and translation control (keeping it in the centre of the socket)
Sensorimotor control & proprioception: This is the most important element of the Rotator cuffs function, interestingly there are loads of mechanoreceptors (detecting sensors for movement) in many of the anatomical structures of the shoulder that are constantly detecting stretch, load, compression etc. so there is lots of feedback and feed-forward loops to stabilise and control the joint for smooth and quality movement of the shoulder.
What causes a Rotator cuff injury?
It has been found that age-related degenerative changes and poor vascular supply are reasons that Rotator cuff tears occur (Hashimoto et al 2003).
This is usually microtrauma rather than one-off trauma due to the high strength level of a healthy uninjured tendon.
This is not that using your shoulder per se is bad but rather abnormal excessive overuse, especially in overhead type activities.
It has been proposed that shoulder impingement syndrome can be a cause of Rotator cuff tears and that the Acromion shape may contribute to damaging the tendon but Gill et al (2002) found no link between the shape of the Acromion process and Rotator cuff tears, so maybe this is not always as relevant as you may think.
What is the relevance to everyday people?
Shoulder pain is one of the most common musculoskeletal conditions accounting for between 7 -26% of G.P consultations in the UK. The Rotator cuff is the most common tendon injury in the human body (Reilly et al 2006).
Templhof et al (1999) looked at 400 people over 50 years of age, who had no signs or symptoms and they found that 23% of them had rotator cuff tears! By the age of 80 more than 50% had tears but remember these were not causing any issues at all! Rotator cuff tears have also been found in younger people without problems too, for example, Connor et al (2003) found that 40% of elite overhead sports athletes have Rotator cuff tears!
So this shows tears are very common especially through the natural ageing process or from excess abnormal overuse especially overhead activity but they don’t have to be an issue but they obviously can be.
It is more about where the Rotator cuff tear is located and how many tendons are affected:
When you think about tendons you tend to picture a cord or rope type structure but this is not quite the truth when it comes to the Rotator cuff tendons.
This was first found back in 1993 by Burkhart, they found a thickened area that was 3 times thicker in the Supraspinatus and Infraspinatus tendons, called the Rotator cable and there was another area in the tendons, which they called the crescent. The crescent area was thin and had poor blood supply making it more likely to tear but also less important if torn. This cable connection acts as a suspension bridge between the front and back of the shoulder so it can give some amazing function to a torn Rotator cuff.
Collin et al (2015) found that tears in the cable parts were more likely to be more symptomatic and have a poor function and if tears were in the crescent area then there was often much greater function and in some cases absolutely normal function. This is why I have seen patients at my clinics in Stoke-on-Trent who have massive tears but incredible function and their doctors are amazed as it makes no sense to them how they can move their arm so well.
What are the signs and symptoms of a Rotator cuff injury?
The obvious one is shoulder pain that is often felt into the Deltoid rather than exactly where the tear is. Now you would assume that the larger the tear the more pain that’s you’d be in and you’d be wrong in this instance. Gotoh et al (1998) found smaller tears had more pain than larger ones due to chemical mediation in smaller tears and as the tendons are poorly innervated, the pain is often from other structures that are affected such as the bursae, which are full of great nerve supply.
Loss of function is another symptom that you can get, so much so it can create what’s called pseudo paralysis, which is where you can’t actually lift your arm up and out to the side. This can be from more severe tears with cable involvement but even smaller tears can cause so much pain that they can create inhibition of the muscles also giving rise to this loss of function.
How do you diagnose a Rotator cuff injury?
The first thing is to go through a subjective and objective examination with orthopaedic tests and this can be very effective to diagnose a Rotator cuff tear and this is precisely what we do in our Physio clinics in Stoke-on-Trent. As part of our examination, we will look at various active, passive and resisted movements as they can tell us information about the likely diagnosis. For example, external shoulder rotations in side-lying were found to have the greatest amount of EMG activity in the infraspinatus muscle, which was 62% of a maximum contraction & teres minor was 67% (Reinold et al 2004). So pain or weakness of external rotation can be one element to add to the assessment.
Also, an EMG in prone horizontal abduction at 100 degrees with full external rotation showed that supraspinatus was 82% of a maximum contraction but middle deltoid was 87% & posterior deltoid was 88% (Reinold et al 2004). Finally, Kelly et al (1996) found the ‘full can’ resisted scaption at 90 degrees produced the most supraspinatus contraction with the least co-contraction of the infraspinatus. For subscapularis, the Gerber push with force test gained the most activation with the least co-contraction of Pecs and lats. As you can see all of these gain the most contraction of the various targeted Rotator cuff tendons but not isolate them so care needs to be taken if trying to use these tests in isolation.
The other ways to confirm the diagnosis are scans, so an MRI being the most accurate but even ultrasound scans can be good too. For example, Morag et al (2012) found that 99% of the time the Rotator cable was identifiable and this is useful to determine the need for surgery or not. However, be aware that scans can be misleading in isolation as Rotator cuff tears can be seen commonly but could be from another area. See this video below:
Diagnostic nerve block
Another diagnostic test is to perform a C6 nerve root block to see if the pain reduces. This is because C6 supplies the shoulder joint but there is always a very good chance especially with older patients that they may have a cuff tear and a neck problem. This has massive potential to cause some element of misdiagnosis or incomplete diagnosis making conservative or surgical treatment ineffective due to treating the wrong problem or a problem less consequential to the persons’ symptoms (Dean et al 2013).
What are the other problems that it could be instead of a Rotator cuff tear?
Severe acute rotator cuff tear suspicion if:
Acute trauma but sometimes not with pain and weakness, especially a sudden loss of ability to actively raise the arm. This doesn’t mean definite referral as could be inhibition due to pain but can be suspicious of need to scan to check if needs surgery.
Any shoulder swelling or mass.
Possible Septic arthritis:
Red skin, painful joint, fever & systemically unwell.
Trauma with loss of rotation and abnormal shape.
New symptoms of inflammation in multiple joints.
So referral for investigations and further medical review if:
Systemic symptoms such as night sweats, fever, weight loss or new respiratory symptoms.
Have an undiagnosed severe shoulder pain with severely restricted movement.
A history of recent acute trauma.
Possible joint infection (red skin, fever, systemically unwell).
Malignancy (past history of cancer, symptoms or signs of cancer, mass or swelling, lymphadenopathy, unexplained deformity).
Acute rotator cuff tear caused by trauma (trauma, pain and severe weakness).
Neurological lesion (unexplained wasting, significant sensory or motor deficit).
If there is a history of instability (the shoulder has ever come out of joint, or the person is concerned their shoulder may dislocate during certain activities or sport) a diagnosis of instability is likely.
Other potential injuries:
Acromioclavicular (A/C) joint injury or disorder:
Pain and tenderness over the A/C joint, pain at the top of shoulder elevation and a positive cross-arm test.
Reduced passive external rotation and a capsular pattern.
Shoulder impingement syndrome:
Inflammation of the bursa in the Subacromial space.
Degeneration (arthritis) of the shoulder joint.
(Royal College of Surgeons 2014)
How likely am I to recover from a Rotator cuff injury?
Unfortunately, 50% of moderate full-thickness Rotator cuff tears will get worse over a 2 year period of time, due to the common degenerative nature of Rotator cuff tears (Edwards et al 2016). However, this means that the size of the tear will get larger but this doesn’t necessarily mean that the symptoms or function will get worse! This is highlighted nicely by Barreto et al (2019) when they MRI scanned people with one-sided shoulder pain and scanned both shoulders to see if there were any differences. They found minimal differences even with Rotator cuff tears, there was only a 10% more severe supraspinatus tendon injury on the painful side, highlighting that damage does equal pain to an exact level. This being said, patients with tears are still far more likely to have symptoms than those without (Oag et al 2012). Your recovery will depend on many factors and they are not just mechanical in the shoulder. Yes, the tear location, tear size and tendon tear amounts all influence how likely you will recover well but other factors are not as obvious, Unruh et al (2014) found that patients low activity levels, poor general health factors and lower social status all do worse in recovery terms.
See above, our beliefs and expectations also have a huge role in your recovery as shown by Dunn et al (2016).
Age is also relevant due to the tissue quality and natural degeneration of the tendon with age and another potential stumbling block is something called central sensitisation, which occurs in chronic conditions. This is a heightened state of pain sensitivity from the central nervous system and this not well correlated with injury state and in some cases can even be present when the structural issue is gone. This in itself is very complex and therefore for another article in the future.
How do you treat a Rotator cuff injury?
Try paracetamol first but if the pain is too high this will be ineffective, in this instance use oral non-steroidal anti-inflammatory drugs (NSAID) like ibuprofen and if the pain is still severe then the next level is Codeine (Gray et al 2016). Remember that these drugs have negative effects and certainly NSAID’s can negatively affect healing and repair so make sure that if these are used in the early stages and only as needed to enable function. So if they don’t enable this then stop using them immediately and if you do use them only use them for a maximum of 2 weeks (Diercks et al 2014).
Manual therapy can be used to improve pain levels in the short term so massage and manual therapy can be useful at this early stage. For example, mobilisation of the cervical spine (neck) was found by McClatchie et al (2009) to decrease shoulder pain and increased shoulder abduction range of movement. Further to this Thoracic Manipulation may provide some relief as highlighted by Boyles et al (2009), where they found that 48 hours after the manipulation all testing of the shoulder had improved.
Get moving and don’t completely rest
Listen to your body! It has been shown that trying to keep functionally active and using the shoulder as your pain allows has beneficial effects in the early stages of a Rotator cuff injury, so listen to your pain and try to remain active, don’t just rest and cradle the arm as this will do more harm than good. If work is irritating the problem then light duties or even a short burst of time off work may be appropriate. Hobbies or sports may need to be adapted or stopped temporarily depending on whether they irritate the condition (Artus et al 2014).
Get going with Physio!
Early initiation of physio will be needed, firstly for pain relief and secondly to rehab the shoulder back to full function. If this conservative approach is effective then this could be a process of around 6 months of rehabilitation (Artus et al 2014).
Even though you need to rehabilitate for function with your rehabilitation exercises, some people are non-functional in the early stages so in this case, it is sensible to start with less functional exercises specific to the shoulder and also away from the shoulder too.
Away from the shoulder:
Look at things such as single-leg balance, single-leg squat, weight transference drills, lunging etc. are great examples of exercise that you can do that don’t involve the shoulder directly. There are several reasons for this approach, the first is why not? There is no point allowing the rest of the body to decondition when it isn’t injured. The other element is the cross over effect, which is when you can get stronger in the limb that you don’t train with an effect of crossing over strength from the one that you do. (This effect is explained more in the video below). The final reason is since there may be issues with movement in other parts of the body in the kinetic chain and this will create a change in movement and force through compensation that may have impacted the shoulder in the first place.
So with this in mind make sure you assess Core control & Thoracic (mid-back) flexibility as these will influence the shoulder due to there interdependence with the shoulder (Sueki et al 2011). Try rounding your mid-back and try to lift your arm above your head, it’s much more difficult to do. Next, sit upright with good posture and try again, easy peasy! So they are interlinked and can be relevant in some patients, so doing some thoracic mobility or control exercise can be very effective.
Early shoulder specific rehab:
Train the scapula muscles:
Merolla et al (2010) found that abnormal scapula movement and control created inefficient length-tension ratios for the Rotator cuff muscles meaning this could create a secondary functional weakness in the Rotator cuff in certain positions. So training the scapula muscles is important in rehab.
Here is a basic early-stage scapula exercise:
Train the Rotator cuff directly:
Now, most physio’s frown upon the basic exercises but they do have their place in the earlier stages of rehab so isometric shoulder strengthening or if able lateral and medial rotation strengthening is great at this point, providing that you progress them as they improve! (Morrison et al 1997).
If you have enough movement and function to perform some closed chain axial loading exercises then these are a great idea even at this stage and have been described by Kilber et al (2001) as the primary means of early shoulder rehab & functional rehab protocols. so exercises such as Shoulder Stabilisation In 4 Point Kneeling can be a good example of these type of exercises.
Be aware that in the earlier stages you may have to work on tolerance rather than effort so due to low injury tolerance you will be employing a low intensity and higher frequency approach but as you progress then the intensity can increase and the frequency decrease accordingly.
As you improve with symptoms and function within the earlier exercises then you need to progress things on providing that you tolerate the progression made. Here are some more examples of intermediate rotator cuff rehab exercises below. It can also be noted that manual therapy can still add some benefit to the exercise based rehab up to 22 weeks after the Rotator cuff tear and has been shown to improve function better than placebo treatments (Page et al 2016).
Proprioceptive / stability exercises
Rotator cuff dominant exercises
Advanced functional strengthening:
This will depend on the activities of the individual. You need to think about the movements of the persons’ sport or work and create exercises that load the cuff in these ways. For example, a sportsperson who throws will train the motions that occur in that action. So below might be an exercise to include:
So the advanced rehabilitation exercises take a little imagination. The progression of these types of exercises should be as follows:
Simple to complex
Meaning that you should break down the action into smaller bits and work them together gradually. For example, a cricketers’ bowling action involves the entire body so you could start with just arm motions then add some body movements then leg movements to combine to the exercise.
Slow to fast
Not much explanation is needed for this one, start a new exercise or movement slowly and once mastered speed it up to the speed needed in real life.
Static to dynamic
Start a new sport-specific or work-specific exercise in one position at a time then start to gain strength and control through a fuller range over time.
Programmed to random
So once you have a few drills then you can program these in advance so the patient knows what is coming next but after this try to surprise the patient with unexpected challenges. a great example is doing the overhead rotator cuff exercise but randomly knocking the ball so the patient has to react.
Not to failure to failure
At first, don’t try to train the cuff to failure as it will just overwork it and this could cause issues but in real life, the person may need fatigue resilience of the cuff so you should gradually train closer to failure in each exercise over time.
If conservative treatment isn’t effective at 6 weeks then:
A corticosteroid injection can cautiously be used in the first 8 weeks if the pain is very severe but it has to be used along with other conservative treatments such as physiotherapy as the injection only enables the rehab to be performed and in itself doesn’t cure the problem and as we know could make the structural integrity of the tendon worse (Dierks et al 2014). It is also only advisable to have a maximum of 2 injections due to the negative effects on the tendon (Royal College of Surgeons 2014).
Amzingly, Mohamadi et al (2017) found that when you compare the effectiveness of a corticosteroid injection to a placebo injection for Rotator cuff injury there is no difference between their effectiveness for pain at the 3-month point.
If after 12 weeks no real progress is being made then:
The surgical options are an open repair or an arthroscopic repair (keyhole) repair of rotator cuff tears. According to Carr et al (2017), 40% of all Rotator cuff repairs fail within the first year and the bigger the tear and the older the individual the more likely a re-tear will occur. Surgery may not always be needed and the likelihood of not responding to conservative treatment is poorer if you have anteriorly located tears. You may also need to have more than two tears to increase the potential for surgery as these tend not to do well with rehabilitation. However, they can still respond well as it depends on the cable element still interconnecting the tendons to give good function (Collin et al 2015).
Postoperatively, Physio is needed to get function back, re-tears can happen and there was an interesting study looking at arthroscopic rotator cuff repair retear rates compared to post-op stiffness. They found that patients who had Rotator cuff repairs and had post-op stiffness relating to external rotation restriction had significantly less re-tear rates compared to those who had less stiffness. For patients with postoperative stiffness at 6 weeks, the retear rate at 6 months was 3%, whereas the rate for nonstiff patients was 19%. It was also noted that although stiffness improved by 5 years it doesn’t fully resolve even at 9 years down the line. So this may highlight the need to be very careful of external rotation mobility post-op cuff repairs and stiffness is not definitely bad (Millican et al 2020).
So as you can see a Rotator cuff injury isn’t the be-all and end-all. It’s just more complicated than that. Tears can be present in the young and old without any signs or symptoms. It may be related to the location, size and amounts of tears that relate to problems. Physiotherapy can certainly be effective but don’t just focus on the shoulder and don’t just do external rotations with an exercise band and expect that this will be enough. If conservative treatment is ineffective after 3 months then more invasive treatment like surgery could be the answer. This is by no means a guarantee as surgery is sometimes ineffective due to the poor quality of the tendons in the first place and can also be due to secondary issues including central sensitisation.
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The content in this blog article is provided for general information purposes only and is not meant to replace a physiotherapy or medical consultation.