Discussing what’s frozen, and what’s not
By ED DAVIS, of Wyvern Physiotherapy (based at The Terrace)
One of the most common opening complaints we hear in Physiotherapy is the simple “I’ve got a frozen shoulder”. Easy to understand in a large joint which isn’t moving well, but does it really help semantically when a true frozen shoulder benefits most from time, as opposed to more organic structural pathology which thrives in the rehab environment.
Let’s examine.
The shoulder joint is a large synovial joint in the upper half of the body. A ball and socket joint, it allows for multiple directional movement enabling significant task function.
The shoulder joint itself is comprised of the “ball”, known in anatomical language as the head of the Humerus, and the “socket”, known as the Glenoid Fossa. The articulation is somewhat akin to a golf ball sitting on a golf tee at a 90 degree angle.
Not particularly stable when thought of like that, there are a number of other cartilaginous and tendinous structures which further support the joint to keep it stable.
The most common of those tendons is the rotator cuff group, commonly referred to as “the cuff”. These act to both support movement and stabilise the shoulder when the arm is placed in positions where the forces acting upon joint mean it has reduced congruency (contact between the moving bones) in the moment.
All of these structures are contained within the Synovial capsule, a double layered membrane enclosing the joint to provide protection on the outer layer, and keep the joint nourished from the inner layer.
It is from here, that our conversation around frozen shoulder begins.
Frozen shoulder, or “Adhesive capsulitis”, is a disorder the synovial joint capsule where it becomes thickened, angry or inflamed, and causes significant pain when the shoulder joint moves and then attempts to stretch the capsule, as is possible in a healthy joint.
The capsule is full of little nerve endings, like little pain messengers waiting to inform your brain the moment the capsule is placed under load. This is often described as a sharp, stabbing pain, or a catch. It often occurs when an individual with frozen shoulder reaches or reacts to movement quickly by moving the arm away from the body and thus stretches the capsule.
The Synovial capsule in a healthy joint allows movement in all directions. An inflamed or angry capsule, causes proportional movement loss for certain directions of movement. This is known as a capsular pattern.
The Capsular pattern of movement loss for the shoulder joint is as follows:
Most restricted movement - External Rotation. With the arm pinned against the body and the elbow at 90 degrees, the ability to rotate the arm away from the body will be heavily restricted, and not correctable passively (we will return to this).
Moderately restricted movement - Abduction. The ability to lift the entire arm away from the body in a sideways movement will be restricted, but not so much as external rotation - it is often possible to achieve between 70 and 90 degrees of abduction with a frozen shoulder.
Least restricted movement - Internal Rotation. The ability to move the hand behind the back feels tight, often limited to between the buttock fold, and belt line.
The key distinction for diagnosing a frozen shoulder is that movement remains restricted when assessed passively (by a clinician, with minimal muscle activation), as it does when an individual actively attempts to move their shoulder. In a frozen shoulder, strength is often unaffected.
I should note at this stage, that Osteoarthritis of the shoulder, presents in a very similar fashion to a frozen shoulder - and the key differentiator, is age. The difference between the two can be established with the help of a physiotherapist.
Frozen shoulder, is often known as the “Disease of the fifth decade”, and tends to affect people mainly between 45 and 65. There are of course anomalies which fall outside of this bracket, but the majority will fit into that age range.
Individuals with conditions such as diabetes, thyroid disorders, or a recent trauma to the shoulder are more susceptible to a frozen shoulder. Lifestyle factors such as excess alcohol, and individuals with vitamin deficiencies can also be at risk.
Frozen shoulder tends to have a number of stages, commonly described as either two or three stages.
My preferred way of describing a frozen shoulder is through two stages - the pain and stiffening stage, and the painless but stiff phase. After these two phases, the capsule settles and movement gradually returns. During the second of these stages - despite the stiffness, the human body is remarkable at adaptation and a high level of function will be still be evident and achieved.
The three-stage description works in a roughly similar way to the above, but is described in terms of stage 1 - the freezing stage, stage 2 - the frozen stage, stage 3 - the thawing stage. There is no right or wrong way to understand the natural history of the disease and some readers may find it easier to understand using the three stage model.
Whilst physiotherapy can be helpful when movement is returning, there is often not a lot that can assist in the acute phases from a physical standpoint. Steroid joint injections are helpful if the pain is severe, affecting sleep and can help calm the joint capsule down. These can be obtained by a GP, appropriately trained physiotherapy or shoulder specialist orthopaedic doctor.
Physiotherapy can be helpful though - in identifying a frozen shoulder and providing you with this advice, or by treating the underlying shoulder problem - if it turns out to be another disorder of the shoulder, without being a frozen shoulder.
At Wyvern Physiotherapy, we can help you with just that. Email post@the-terrace.co.uk with questions or to make an appointment.
This article is for information only and not a tool for self-diagnosis. Professional assessment should be sought for individualised advice and guidance if concerned about your shoulder pain.