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Rotator Cuff Exercises - How Good Is External Rotation For Shoulder Function?

Written by: Nick Jack
Category: 2014
on 22 July 2021
Hits: 873

Whenever you talk about exercises for the rotator cuff or for preventing shoulder injuries the very first exercise people think of is the external rotation exercise using rubber tubing. How come nearly every shoulder problem needs external rotation work? Do they all have weak external rotators? Many physical therapists and trainers will say yes, and this will often be their “go-to” exercise for almost every shoulder injury they see. Their belief is that the external rotators are weak and over-powered by the larger internal rotator muscles of the pecs and lats and therefor they need to be strengthened. However, this type of logic ignores the true role of the rotator cuff and assumes so many critical factors that are often the reason behind the imbalance being created in the first place. In this article, I will discuss how these exercises often cause more problems than they solve and if you want to improve stability and function of the rotator cuff, you will find there are much better choices that will get you out of pain and back to full function.

The Shoulder Is The Most Dynamic Joint In The Body

 

There is more movement possible at the shoulder joint than at any other joint in the body and research shows that it has over 1,600 positions it can obtain! Unfortunately, this dynamic mobility with extreme ranges of movement comes at a price and exposes the joint to lack of stability. There is a constant balancing act between mobility and stability whenever we talk about the health of the shoulder.

For example, elite swimmers who over-stretch their shoulders in an attempt to increase the range of their stroke, without improving their functional stability, are at increased risk of injury to the rotator cuff. Tennis players and throwing athletes like baseball pitchers and cricketers are essentially asymmetrical, and develop considerable greater shoulder external rotation in their dominant shoulder versus their non-dominant shoulder. This asymmetry leads to instability and a host of problems if left unchecked.

It is at this point we often see the sporting athletes using exercises like external rotation with rubber tubing to keep their rotator cuff in check. I myself used to do this too and you can see how I even suggest this in my article from 7 years ago about rotator cuff training.

 

But is this the best way to achieve this? When you really understand how the rotator cuff works and the delicate balance between mobility and stability you will see that these exercises can create a stack of problems.

What Does The Rotator Cuff Really Do?

The rotator cuff is made up of the teres minor, the infraspinatus, the supraspinatus and the subscapularis up the front.

  1. Supraspinatus - The supraspinatus is located at top of the scapula. This muscle allows the shoulder to abduct or raises the arm and moves it away from the body. This muscle is often the one that ends up with severe pain and weakness from constant rubbing and friction. Weakness in this muscle means you will be unable to lift your arm.
  2. Subscapularis - The subscapularis is at the front side of the scapula, or when looking from behind it is tucked underneath the scapula. It allows the shoulder to internally rotate or turn the upper arm towards the body.
  3. Infraspinatus and teres minor - The infraspinatus and teres minor muscles are on the back of the scapula. They enable the upper arm to externally rotate or turn outwards away from the body.

When you look at the shoulder you have to look at it as an entire complex and interaction with the thoracic spine, scapula and various muscles that contribute to providing movement and stability to these areas. The role of the scapula and muscles like serratus anterior and lower trapezius cannot be understated whenever we talk about the rotator cuff.

 

Although each rotator cuff muscle moves the shoulder in a specific direction, they work together to ensure that it is centred in the joint throughout all ranges of movement. While internal and external rotation is something they are responsible for, their main focus and where these four muscles really work well to­gether, is to centrate the humeral head.

As we raise our arm up and down, the rotator cuff works together as a group to keep the humeral head centrated within the joint. If we lose that centration, we get some extra mobility of the humeral head within the joint, and that begins to pinch some of the structures around it. When that happens, and constantly pinch and compress things over and over and over again is when inflammation starts. That is how people develop ten­donitis and bursitis type problems.

The rotator cuff working together as a group is the key in preventing this and maintaining healthy shoulder function.

Why Do People Focus On External Rotation Exercises?

If centration of the humeral head is the main purpose of the rotator cuff why do so many people use external rotation exercises? I am not sure exactly why this is still the case but from what I can see the main reason people continue to focus on these exercises alone, all comes back to the upper cross syndrome approach to treating shoulder and neck pain.

This is a syndrome named by Dr Vladimir Janda where “tightness of the upper trapezius and levator scapula on one side of the body crosses with tightness of the pec major and minor. Over time this develops into the dowagers hump seen on the right.

 

In combination with this tightness the opposing muscles develop “weakness” of the deep cervical flexors ventrally crosses with weakness of the middle and lower trapezius and serratus anterior muscles crucial for optimal shoulder function. This pattern of imbalance creates joint dysfunction at both the neck and the shoulder resulting in pain and compensatory movement.

Typical correction for this is to strengthen the weak upper back muscles which also provide external rotation and stretch and weaken the muscles that provide internal rotation of the shoulder being the pecs and lats. People believe that if they apply this simple formula everything will go back to normal. Unfortunately, this is very rarely the case and I will explain why.

The Scapula Is The Key

I said in the introduction how come nearly every shoulder problem needs external rotation work? Does every single person with a shoulder problem have weak external rotators? While these exercises might help to hold the head of humerus depressed during the external rotation, it might come at a cost to how the scapula moves. And when this happens you are guaranteed to have many problems.

External Rotation is deeply connected to Scapular Retraction as these two things need to happen in perfect timing, or you will develop weakness and muscle imbalances very quickly. You can experience this yourself by comparing the feeling of doing this movement with your shoulder gently falling forward versus really focusing on scapular retraction during the movement. 

Feel the massive difference? Much smoother and the range is much greater. 

What this tells you is that you need scapula retraining and not exercises to focus solely on the rotator cuff muscles. They are merely reacting to the poor stability from ineffective scapula timing and movement. Now if you are thinking this means I need to do heaps of scapula retraction work you can think again. For that is the second mistake that many people make and this often leads to depressed shoulders and shoulder impingement.

One thing we have been told from a very early age is to pull our shoulders back and down as this is great posture. This is such a bad instruction for the consequences of sustained back-gripping are that this will force the joints of your spine together and limit the ability of your thoracic spinal joints to bend forward and rotate as they are required during many movements.

Trigger points and pain will develop in your middle back muscles (rhomboids and middle traps) due to overuse which in turn prevents the scapula from achieving upward rotation. If these big adductor muscles continue to hold on tight you will have difficulty rotating your trunk and turning your head!

Excessive use of deadlift’s, farmer’s walks, chin-ups and rowing movements can produce what is known as “Excessive depression of the shoulder”. Excessive use of cable external rotation can also play a part in developing this problem. How ironic, for the exercises you thought were improving your posture were really causing you a stack of dysfunction!

 

Retraction of the shoulder muscles is a normal part of bio-mechanics during the phase of pulling exercises and also in the easier phase of pushing exercises. However over doing these exercises or consciously squeezing your scapula together (usually the rhomboids and middle trapezius) can completely disrupt the timing and sequence of how the shoulder needs to move. Even worse is the exercise is if performed poorly it can reinforce the scapula into retraction in a downwardly rotated and anterior tilted position, creating more tightness, impingement, and discomfort. This alignment and altered motor control issue cannot be improved by ‘strengthening’ the scapular retractors or by performing more scapular retraction exercises, as it will often be more of a thoracic dysfunction, and poor mobility with the scapula that is the problem.

Towards the end of this article I will give you plenty of ideas of how to prevent this. I have covered this in great detail before in the articles below

When in balance, the muscles of the scapular complex work synergistically to maintain the scapula in upward rotation and posterior tilt.

 

If your scapula is sitting in anterior tilt or downward rotation even a just little bit too much, then the Supraspinatus tendon is going to rubbed and frictioned during the movement under the Acromion Process. And if this happens you are going to be in pain very soon.

And lastly if there is even a little laxity and anterior shear in the glenohumeral joint, then this will be exacerbated as you externally rotate. NOT good! This is where we see what is known as anterior humeral glide.

Anterior Humeral Glide

The anterior humeral glide is a result of the of scapulohumeral muscle imbalances and is easily observed when a client performs a rowing movement. You can easily see a divot at the rear part of the shoulder and the head of the humerus is pushed forwards. This is when you see more than one third of the head of humerus sitting forward in the socket. This alters the axis of rotation.

There is reasons for this are often due to short and tight posterior rotator cuff muscles infraspinatus and teres minor that will not allow the humeral head to move back into the glenoid fossa causing an anterior shirt. And the second reason is muscle inhibition of subscapularis and also serratus anterior from the pecs and lats during the movement of internal rotation.

This means that the external rotators need to be LOOSENED and not strengthened as per the external rotation exercise. Any attempt to apply strengthening of these muscles will make shoulder instability significantly worse, rub the supraspinatus tendon and create stiffness in the shoulder region to protect it from further injury.

For the major power muscles, it is important that flexibility allows freedom of movement for the body. For the rotator cuff, the critical issue is the balance of forces centring the head of humerus, and to a lesser degree, freedom of movement. It is more critical that the internal and external rotators are equally flexible, rather than how flexible they are.  Too much flexibility at the expense of muscle control puts strains on the soft tissues and causes injuries such as rotator-cuff tendinitis and degeneration, labral tears, subluxations and possibly even a dislocation.

This is why I prefer trigger point release using self-massage tools over stretching for these muscles. Watch the video below to see an example of this.

  

This is very consistent with most cases of shoulder impingement I see these days and why it is very important to complete an assessment to find this out.

Over the past 2 years I have been working with a guy who has hypermobility and had a left shoulder that needed trigger point release of teres and infraspinatus followed up with scapula exercises and strengthening of serratus anterior and lower trapezius. After a few months he was pain free and back to normal. About a year later he developed pain in his right shoulder which is his dominant arm and this was due mainly to poor posture and inactivity as a result of the Covid lock-downs. However, this injury was much different. Whereas last time he had anterior glide that needed trigger point work, this time he needed to do external rotation exercises to tighten up the posterior rotator cuff. This is a classic example of where the pain feels the same, but the reason for it is completely different. And as a result the corrective exercise strategy must also differ.

Be Careful of Rotator Cuff Fatigue!

Let’s say we have identified you do require strengthening of the external rotators, how much is enough? Only mild contractions of the rotator cuff is necessary for stability and therefor rotator cuff strengthening programs DO NOT need to fatigue these muscles to improve their function. They are not designed the same as other muscles and should not be trained the same. In fact fatigue of the rotator cuff muscles can cause as much as 2.5mm of unwanted migration of the humeral head during abduction (Chen et al. 1999).

This is a big mistake often made when people use the external rotation exercises that can very quickly overload the rotator cuff muscles that may already be fatigued. When this happens they set themselves up for trigger points and a host of compensatory movements that will inhibit muscles like serratus anterior and lower trapezius.

This is particularly true of the glenohumeral joint where the primary source of stability are the rotator-cuff muscles working in conjunction with other soft-tissue structures such as the capsule, ligaments and cartilage. Strengthening is very important but you must be careful how you approach this.

What Exercises Do I Prefer To Use?

My first place to start is to ensure you have mobility with the thoracic region and the pecs in particular. These two areas are prone to shortness and tightness that will ruin any attempt to stabilize and strengthen the shoulder.

The Pec Minor can be a massive problem in the beginning and you absolutely must shut this muscle down if the following exercises are to stand a chance of restoring function. The pec minor dominates over the small stabilizers and pulls the shoulder into internal rotation and consequently disrupts the timing and placement of the scapula. In addition to this, the thoracic region is one where we see people adopt a hunched posture (known as kyphosis) and just like the pec dominance leaving this unattended will make it near impossible to complete the following exercises effectively.

Watch the two videos below to see examples of how to improve these areas.

 

You will find additional stretches and assessments to use by going to this article – How to identify mobility restrictions affecting how you move

Once you have begun working on this it is time begin improving scapula function and removing any trigger points that are inhibiting you from doing this. It is important to do this conjunction with the mobility work for they work better when completed at the same time. I already showed you a trigger point drill earlier to use now I will show you what exercises I like to use to improve scapula stability.

Serratus Anterior Wall Slides

Of all the muscles we find common to all shoulder problems it is weakness with the serratus anterior. In Even Oscar's book "Corrective Exercise Solutions For Common Shoulder & Hip Injuries" , a must read, he provides a table of what happens when stability muscles are inhibited.

The secret to restoring scapula function is to teach movement mechanics that force the right muscles to the right job at the right time. Of all the exercises to use for scapula control, the wall slides would be my favourite. This is the purpose of the wall slides exercise and it does an amazing job of restoring these muscles during an overhead movement

There are 3 key concepts specific to ALL shoulder injuries and dysfunction that must be addressed if you want any chance of succeeding in correcting your problems. These relate to relearning movement patterns that coordinate and sequence ideal and optimal movement mechanics.

These 3 key concepts specific to the shoulder are:

  1. Optimal Thoracic extension and mobility
  2. Posterior tilt of the scapula
  3. Upward rotation of the scapula

The wall slides drill to address the 2nd and 3rd problem very effectively. Watch the videos below of two versions I might try.

 

 

Single Arm Stability Drills

This test is quite difficult to do and integrates the entire body with a huge emphasis on shoulder stability. Mobility and stability of the shoulder are maximally challenged along with the stability of the trunk and core. This may be too painful for most with shoulder pain, so if it hurts leave it out until your pain has subsided. However, this can be a great test to use when you are not in much pain and want to know if your shoulder is ready to complete functional exercises or activities without aggravating your joint and going backwards.

 

I would also try to progress these exercises to the push-up once I feel I have mastered the single arm stability. Push-ups are arguably the best exercise for strengthening the serratus anterior and are a better choice for most people in the early stages of strengthening as the closed chain kneeling position provides greater stability to the scapula and shoulder joint. As long as you have adequate mobility with the pecs, lats, posterior rotator cuff, and your technique is of high quality this exercise will be great for you.

Below are two videos with push-up examples for you to try.

 

Single Cable Push & Pull

These exercises are great for developing strength and balance within the shoulder joint. The push in particular is very useful for it targets the serratus anterior perfectly. The other unique aspect to these exercises is that they mimic throwing actions and have a heavy reliance on the core for providing trunk stability.

The single cable push utilizes the anterior oblique system, which is the system that integrates the upper body and lower body via the obliques to help provide stability and mobility in the action of walking or running. This is important in providing that initial stability during the stance phase of gait and then contribute to pulling the leg through during the swing phase. In this movement the obliques and the contra-lateral adductors work in perfect sync to create movement.

Training this system is essential for the sporting player who use multi-directional movements as it enhances stability as speed increases in activities such as sprinting, and also when needing to brake or change direction. Any throwing sports like baseball, tennis and also the sport of boxing this movement pattern is essential. Deficits in the sling is often where you commonly see injury occur in most ball sports.

 

Read this article to see more - Why the single cable push is more than a strengthening exercise

Turkish Get-up 

Last but not least is the Turkish get up. It could be argued that this is more of a mobility challenge for some or a strength exercise for others. It is one of those very unique exercises in that it is all of them! This really puts all of the pieces of the puzzle together in one exercise with stability being the biggest requirement for completing the exercise which is why it is the ultimate shoulder stability movement.

(insert video)

To give you an idea of just how good this is here is a list of the benefits:

  1. Greatly improves shoulder stability and thoracic mobility at the same time!
  2. Improves overall body stability and integration between upper and lower body
  3. Promotes reflexive stability of the torso
  4. Encourages great mobility of the hips and thoracic spine, the two areas most people are lacking
  5. Improves the body's ability to coordinate and enhance balance from lying to standing
  6. Develops upper body strength, trunks strength, and glute strength

You can read more about this awesome exercise and all of the things it can do in the article Why The Turkish Get Up Is The Ultimate Exercise

Do You Need More Help?

There is obviously a ton of other exercises and assessments I have left out from this article so if you are struggling with an injury right now I encourage you to get a copy of our detailed report on Shoulder Pain. This detailed report we take you through ALL of our assessments, tests, drills, stretches and advanced methods we use in our studio every day, and this has over 95 pages of information complete with exercise instructions, pictures and a 6 month program to walk you through the steps of overcoming this injury once and for all.

Click here to see more information about this or click the image below to get your copy straight away.

 

Summary

That concludes this detailed look at the external rotation drills that are used way too often for rotator cuff strengthening. In some cases it may be okay to do this if you have weakness but not laxity with the shoulder. However, if this is your go-to exercise and you use it for no other reason in that it targets the rotator cuff muscles, you will be in trouble. The shoulder is so dynamic and complex that you will need a much more intelligent and carefully structured plan to restore it back to normal if injured. If you are using these exercises for injury prevention you are really wasting your time with endless reps with these as you should spend time with maintaining mobility to the thoracic region and stability to the scapula. I hope this article helps you understand the shoulder better than before and gives you better ideas of how to train more effectively.

For more ideas and information on specific topics I may not have covered in detail be sure to check out our INDEX PAGE on the website that has over 300 of our best articles. These are all sorted into categories for quick reference so you can find what you are after more easily.

And if you live in Melbourne Australia and need specific help with your exercise program please feel free to reach out to me by clicking the banner below and we can organize a time to discuss how we can help you. For online Zoom calls I DO NOT provide free consultations. For more information go to the online training page to see how this works.

About The Author

Nick Jack is owner of No Regrets Personal Training and has over 15 years’ experience as a qualified Personal Trainer, Level 2 Rehabilitation trainer, CHEK practitioner, and Level 2 Sports conditioning Coach. Based in Melbourne Australia he specialises in providing solutions to injury and health problems for people of all ages using the latest methods of assessing movement and corrective exercise.

References:

  • Shoulder & Scapula Injuries in Athletes - By Sports Injury Bulletin
  • Fixing Your Shoulders & Elbows - by Rick Olderman 
  • Movement - By Gray Cook
  • Corrective Exercise Solutions for the hip and shoulder - by Evan Osar
  • Diagnosis & Treatment Of Movement Impairment Syndromes - By Shirley Sahrman
  • Core Stability - by Peak Performance
  • Athletic Body in Balance - by Gray Cook
  • Anatomy Trains - by Thomas Meyers
  • Motor Learning and Performance - By Richard A Schmidt and Timothy D Lee
  • Assessment & Treatment Of Muscle Imbalance - By Vladimir Janda
  • How To Eat, Move & Be Healthy by Paul Chek
  • Scientific Core Conditioning Correspondence Course - By Paul Chek
  • Advanced Program Design - By Paul Chek
  • Twist Conditioning Sports Strength - By Peter Twist
  • Twist Conditioning Sports Movement - By Peter Twist
  • Functional Training For Sports - By Mike Boyle