Understanding the True Origins of Frozen Shoulder Pain
Frozen shoulder is a stressful experience for anyone. The term itself is only descriptive, and not a reliable diagnosis. The “frozen” aspect refers to an extreme limitation of pain-free movement, but in my experience, this is in general not due to capsular adhesions, but splinting adaptation from trigger points in muscles. Mainstream medicine fails to provide any reasonable explanation of why this condition develops. The mainstream western worldview regarding the origins of pain completely fails frozen shoulder sufferers. In my experience, this is a very treatable condition if you discard conventional wisdom and are willing to take a fresh look at how situations like this develop in the body.
The common worldview assumes that shoulder pain, and pain in general, originates in a tear or some other kind of injury that needs to be repaired. My own work has show me that this generally is untrue - I can help shoulder clients get out of pain very quickly, and they can learn to take control of their own health. If the condition were truly injury-based or adhesive capsulitis, it wouldn't respond in a single session as our cases generally do.
I see progressive shoulder pain and frozen shoulder as way stations along in the body's adaptation to painful movement, which generally begins with the development of some active trigger points. Trigger points develop very easily with chronic or acute overload, can produce severe pain symptoms, and often occur in the complete absence of soft tissue damage or injury. Sometimes, trigger points may develop during the acute phase of an injury, however they cause their own sometimes significant pain referral, entirely separate from whatever acute pain is experienced due to the damage. Long after the injury has healed, the trigger points remain. Surgery and other invasive procedures are likely to leave trigger points in their wake.
A good example of this is fraying of the supraspinatus tendon, also known as a rotator cuff tear. Repairing the tear, which may have little or no contribution to the pain experienced, fails to address either the pain or the original cause of the tear (assuming there wasn’t a specific injurious event such as an accident).
Trigger points and taut fibers in the supraspinatus muscle belly cause pain in the lateral shoulder, and also cause it to bunch up and shorten and pull the head of the humerus up into the glenoid fossa. This reduces joint space underneath the acromion, which then mechanically rubs on the vulnerable supraspinatus tendon. The pain and trigger points remain long after the healing of the tendon, and unfortunately more will be introduced by the trauma of the surgery.
Whatever the initial cause of shoulder pain, I see frozen shoulder as a process of adaptation, a seemingly sensible response of the nervous system to protect the shoulder from further “injury”. This has been confirmed in practice. I've developed a consistent ability over many years to unravel the system of adaptations, causing the pain to diminish and disappear.
Offering Clients A More Empowering Worldview
I always spend some time with my clients talking about their condition and pointing out some of the muscles that could be related to their pain on the referral charts. This gets them thinking – and often they recognize a very familiar pain pattern in their own body.
Most people come in having been told that they have an injury or condition that requires pain killers and possibly surgery. They have little hope, and I find that it’s useful to plant some seeds that will mature as they begin to experience relief during the treatment. I want them to understand the process that we’ll be using to analyze and improve their situation.
Anyone who’s been in pain for a period of time has shifted their normal "set point" toward more sympathetic arousal. This is one of the most difficult features of chronic pain – the nervous system sensitizes and creates new synaptic connections in an attempt to protect the system. The CNS becomes more attuned to nociceptive input from all sources. Emotional and physical danger signals are processed in the same part of the brain - the limbic system. At some point, the experience of pain becomes divorced completely from whatever the initiating issues were.
My first interactions with the frozen shoulder client are designed to demonstrate that I’m listening carefully to their story, that I have some specific ideas about what might be causing their pain (which I will then reference later in the session), and then to begin to gain their trust that I’ll move them deliberately and not cause sharp pain.
Becoming the Client’s Trusted Advocate
Frozen shoulder clients generally come in having had a consistent experience of pain during arm movement (or even at rest) that has lasted weeks, months or years. For some clients, their arm is glued to their abdomen and any departure from that position causes pain, sometimes severe. Someone with that kind of recent life experience isn’t going to simply relax and let you move their arm around at will. There are strong conscious and unconscious neurological holding mechanisms in place that you need to approach as an advocate, not an invader.
My first goal is to begin to get them to trust me to move their arm without protective engagement. I move exceedingly slowly, and I tell them that I’m not going to move them in a way that causes severe, sharp pain, although there will likely be some level of discomfort. I explain the pain scale to them. and give them permission to tell me what they’re feeling at any time. I want to know what they’re feeling and where. It’s extremely important to start to break them of the habit of engagement. Generally they control the movements until their CNS has had some experience of safe, passive motion with minimal pain.
An Adaptive Response to Perceived Injury
The shoulder is an extremely mobile and vulnerable joint, and is reliant for stability on the concerted effort of many muscles. When some of those become dysfunctional with trigger points, the delicate balance is disturbed and nociceptive signals flow to the CNS.
For example, the infraspinatus muscle, in addition to being the primary external rotator of the arm, plays a critical role in stabilizing the head of the humerus in the glenoid fossa during abduction and/or flexion of the arm.
Like many of the rotator cuff muscles, infraspinatus is vulnerable to imperfect scapular positioning as well as poor ergonomics during work and sleep. If it becomes disturbed due to some of these chronic factors, the muscle is likely to develop trigger points. They may remain latent until some other event pushes them into active state, at which point the client starts to experience referred pain in the front of the shoulder upon certain movements of the arm, because the infra participates in most of them.
The discomfort might be minimal at first, but over time, the pattern starts to feel like an injury - not only to the conscious mind of the client, but to the neurological systems that listen to proprioceptors and regulate movement. If it hurts every time you abduct your arm past a certain point, the body begins to perceive that something is injured, and movement feels dangerous. Referred pain is confusing, not only to therapists and clients but to these feedback systems. In the absence of other information, a logical response would be to avoid further “injury” and limit abduction by causing the teres major to engage when the arm nears the danger zone.
So begins the process of “freezing” the shoulder, because the teres major is likely to develop taut fibers and trigger points in response, and its own referred pain starts to show up. The subscap is also vulnerable, because it’s an antagonist of the infra in terms of rotation. The body will begin to lock that down too. Eventually the entire joint is in a downward spiral, and it hurts to do anything, as muscles are used to “splint” or immobilize the entire joint.
Travell & Simons consider the subscapularis and infraspinatus to be at the heart of frozen shoulder conditions. Interestingly, a casual internet search that I did recently on frozen shoulder shows a typical “Frozen Shoulder Pain Pattern”. When compared to a composite of the infra and subscap pain referral patterns, the pattern is almost exactly the same. However, most people don’t associate the frozen shoulder condition with trigger points and referral, but rather with some mysterious process of fascial hardening.
The Postural Assault on Shoulder Health
There are several other ways in which the body’s adaptation mechanisms feed into the frozen shoulder pain syndrome. The typical modern person who sits in front of computers and uses mobile devices a lot is highly vulnerable to what Dr. Vladimir Janda identified as “upper crossed syndrome”, in which the pecs adaptively shorten and overpower the mid and low trapezius. The mid/low trap is one of the muscles that tends to de-facilitate, or go to sleep, when it’s neurologically overpowered by the powerful pec major and serratus anterior.
Over time, the pecs and serratus anterior begin to bring the scapula into a constant state of protraction, which the trap cannot resist. To maintain some semblance of postural alignment and stability, the trap must be shored up so it can resist the pull. The classic hard inter-scapular area that we see in so many clients is the result of an extensive network of taut fibers in this area. The trapezius exists in a kind of limbo state - hardened at a level of mild stretch, but unable to function as an effective dynamic stabilizer of the scapula.
Taut Fibers as Stabilizers
Taut fibers aren’t just a product of dysfunction. Dr. Leon Chaitow pointed out ((Chaitow, L. "Might Trigger Points Sometimes Be Useful? )) that taut fibers can be recruited by the body as a means of providing rigid support in a muscle without excess energy input. The body needs to provide more support in joints that evidence hypermobility or postural distortion.
Taut fibers are a condition in which the sliding filaments get stuck in the closed state, at which point they cannot release without the input of energy compounds such as ATP. Without the ATP, they stay stuck. So in a sense, they become like ligamentous bands in muscle, which is useful from a support perspective but very problematic for healthy movement. As soon as you try to shorten or lengthen the sarcomeres, nociceptive feedback gets sent to the spinal cord, and referred pain is experienced. This alters the proprioceptive stretch response from muscle spindles and other sensors as well.
Satellite Referral – A Missing Link
Satellite referral is the tendency for a muscle that lays under another muscle's referral zone to become troubled and develop its own trigger points. For example, the referred pain from the mid and low trap covers the high trapezius, which then becomes troubled via satellite referral. These high trap fibers when troubled will tend to contract on the short and restrict upward rotation of the scapula, necessary for proper glenohumeral rhythm and shoulder ROM. Humeral stabilizers like the infraspinatus cannot function properly when scapular motion is disturbed, because the humeral motion will be impinged at the acromion.
Satellite referral is extremely important, but not well-documented, even in Travell & Simons. This mechanism sets up a kind of shadow network of relationships between muscles through which dysfunction is propagated.
Satellite referral can produce a particularly troubling situation when the referral happens to occur over a muscle’s antagonist – a situation that I call reciprocal referral. There are a couple of important examples of that in the shoulder. The subscap and infraspinatus are a key pair for frozen shoulder conditions, and the subscap’s referral zone is directly over its antagonist, the infraspinatus. Thus, whenever the infra engages to externally rotate the arm, subscap fibers are lengthened, and at some point its posterior shoulder referral is triggered.
To the proprioceptors in that area, referred pain is real, and the nervous system registers that as a problem in the area and function of the infraspinatus. This will also cause the infra itself to develop TrPs as a satellite. The infra becomes unable to contract gracefully due to the referral of the subscap as well as its own trigger points causing contraction on the short. This can rapidly degrade both internal and external rotation, as both cause pain. The only way that a muscle can stretch is via the action of its antagonists. Without the ability to achieve full stretch, the sarcomeres in both muscles become increasingly dysfunctional.
Another case of reciprocal referral in the shoulder is between the serratus anterior and the lower half of the trapezius. This is a similarly critical functional relationship for healthy shoulder movement. The serratus anterior has fan-shaped fibers that span a considerable arc. Its various fibers protract, rotate and stabilize the scapula. Scapular rotation and positioning are key for healthy, pain-free shoulder movement.
The referral zone for the serratus anterior is directly over the endplate zones of the lower trapezius fibers, making low trap an important satellite of serratus. The low and mid trap fibers are also antagonists to the upper serratus fibers, adducting the scapula. Both must coordinate in any type of scapular motion.
Here is another situation in which engagement of the low and mid trap fibers to adduct and stabilize the scapula can cause serratus stretch referral over the same fibers, just as we saw in the infra and subscap. Over time, the trap develops trigger points and the muscle becomes dysfunctional.
The trap also has a key/satellite relationship within its own boundaries, because the high trap fibers lie under the referral zone of the low trap. When sufficiently active, this presents an additional barrier to scapular rotation. The high trap fibers must gracefully shorten to permit upward rotation of the scapula during abduction. Satellite trigger points will cause the high trap to contract on the short, further inhibiting abduction of the arm.
A Strategy to Thaw the Frozen Shoulder
We can easily see how compromised rotation of the humerus and scapula will lead to a situation that looks a lot like a “frozen shoulder”. We need to work with the body to release trigger points in these key muscles as we reestablish motion. We do so in a particular order that we have found clinically to be most efficient in very severe frozen shoulder cases.
First we must establish enough abduction at the glenohumeral joint to be able to reach the axilla, and therefore the subscap and teres major. Then we can treat the subscap/infra pair enough to begin to increase rotational motion of the humerus. We address scapular rotation and positioning after these glenohumeral motions. All of these are achieved with an understanding of the agonist/antagonist and reciprocal referral relationships as we move the joint.
First Steps: Unlocking the Holding Pattern
With a severe frozen shoulder client, things have gotten so locked down that it will be difficult to even achieve some of the shoulder protocol arm positions that we rely upon for treating muscles like the subscapularis and infraspinatus. Coaching the Body is based on movement of the fibers that we’re compressing, either passively during compression or using MET techniques like contract/relax. If the arm cannot be moved without pain, that approach becomes more difficult. But if we start very slow and with small increments and manual feedback, we can start to teach the nervous system that it's safe to move again.
For this type of client, we have to do some preliminary work before we can even enter the shoulder protocol proper. We have to establish how much and in what ways movement is limited. If we can’t abduct or externally rotate the arm, we won’t be able to effectively reach the subscapularis and cannot shorten the infraspinatus. So we begin very gradually, encouraging the held muscles to release enough to be able to work productively in different positions.
If the client’s arm is being rigidly held close to the body, that’s most likely because letting it abduct produces considerable pain. In the first effort to restore extremely limited motion, you have to consider the shortening side of the joint as well as muscles that block on the stretch. One of our central principles in CTB is that understanding the body’s protective strategies allows us to be an advocate rather than an invasive, forceful “fixer”. Trigger points are not an actual injury, but they do cause a perceived pain that seems like an injury – and has a very immediate effect on the body’s protective systems.
We can help turn off the body’s protective response by providing distraction that interferes with the nociceptive signals produced by trigger points in the stretching and shortening muscles. Manual feedback over the muscles participating in a particular range of motion can turn off the splinting response to a degree. For abduction, we have to consider the primary muscles involved.
Limiters of Abduction
On the shortening side, the supraspinatus, high trap and supraspinatus are likely to be troubled. On the stretch side, teres major and the subscapularis are common limiters. Both are adductors in addition to their rotational function. Pec major, while all branches adduct, is a longer muscle and is much less likely to be a primary limiter at the earliest stages of abduction. Infraspinatus is likely to be involved, as antagonist to subscap and as a primary humeral head stabilizer during abduction.
In Part 2 we'll go over specific treatment steps for a severe frozen shoulder client. We begin by establishing some minimal abduction, which then allows us to get to the subscapularis and other key muscles so we can improve rotation.