“Frozen Shoulder” By Boris Prilutsky

“Frozen shoulder” is not a diagnosis, but a descriptive term for the symptomatology of a number of different diagnoses. Physically, frozen shoulder is expressed by severe limitation in the range of motion on multiple planes and axes. The main cause for the development of frozen shoulder is an inflammatory condition of the rotator cuff muscles (rotator cuff syndrome) and/or the capsule of the shoulder joint.

Rotator cuff syndrome can be the result of trauma such as sprain/strain, irritation of the brachial plexus by over-tensed anterior scalene muscles, hormonal changes that cause accumulation of tension in muscles (the rotator cuff muscles as well as the anterior scalene muscles). The syndrome may result from one or a combination of these conditions. A prolonged existence of an inflammation in the rotator cuff muscles leads to a chronic inflammatory state. This, in turn, leads to calcification of soft tissues, shortening of the muscles, and development of trigger points in the muscles and in the periosteum at the tendon-to-bone attachment areas. As is mentioned above, the capsule of the shoulder joint can become inflamed (capsulitis), and in the transformation from acute to chronic inflammation can cause adhesive capsulitis. Adhesions of the joint capsule can significantly add to the restricted range of motion. It is also very important to consider frozen shoulder as the result of trigger points developing in the anterior part of the deltoid muscle. As mentioned above, rotator cuff syndrome could also be the result of irritation of the brachial plexus by over-tensed scalene muscles. This leads to the gradual accumulation of tension in the rotator cuff muscles. Therefore, it is important to mobilize the anterior scalene muscles in addition to rotator cuff and deltoid muscles.

The Anatomy of the Shoulder Region

The shoulder joint consists of two bones: the humerus and the scapula. The head of the humerus articulates with the glenoid fossa found in the lateral aspect of the scapula. Cartilage is found on both sides of the arthra (joint); the head of the humerus is covered by cartilage, while the glenoid fossa is lined by cartilage. Arthritis results when the cartilage becomes inflamed (microscopic fissuring, erosion, etc.). These two bones are connected and stabilized by a network of ligaments. Ligaments are tough, elastic, belt-like structures of connective tissue that connect bones. The rotator cuff muscles are responsible for stabilization and movement of the shoulder joint. It is also important to consider that the anterior, medial, and posterior deltoid muscles support the movement and stabilization of the shoulder joint.

Should the shoulder region be severely sprained or strained, it could traumatize all components of the shoulder joint region. This can lead to the development of inflammation in the arthra (arthritis), in the bursa (bursitis), in the tendons (tendonitis), and of course, in the muscles (myositis). An inflammatory condition expresses itself with decreased amount blood supply to the tissues, swelling of the tissues, accumulation of excessive amounts of fluid, and restriction in the range of motion. Let’s consider the difference between sprain and strain injuries. A sprain occurs suddenly, from a single event in which a load was placed on ligaments and muscles. A strain (overload) could also be a factor in an inflammatory condition lacking a pull (sprain) act. Muscles and tendons can be strained without a pull. An example of that would be carpal tunnel syndrome resulting from the overload of flexor muscles by a repetitive typing motion. In response to the sprain/strain, muscles react with a reflexive spasm, as protective mechanism against a severe tear in muscles, tendons, ligaments, and other tissues.

An energy crisis can cause muscular tension due to ATP exhaustion. As you know, ATP is the energy source for cellular activities, including muscle function. For example, if professional athletes exercising intensely will develop a higher muscular resting tone. This, in turn, exhausts the ATP stores within the muscle. Over time, an increased muscular tone leads to disturbances in the microcirculation, activation of the pain analyzing system, and of course trigger point development. In either case, whether the spasm results from sprain/strain trauma, or gradual accumulation of tension, it must be eliminated promptly in order to prevent further development of muscular pathology. If frozen shoulder is not adequately and promptly treated, it can lead to an unstable joint. In turn, an unstable joint can significantly accelerate the disproportional development of osteoarthritis.

Nowadays we can find published materials where authors don’t recommend to reduce the protective spasm of muscles. Some authors suggest waiting for 9 months until the clinical symptomatology of frozen shoulder (pain, limitation of motion, etc.) disappears by itself. Checking the references offered, one would find that most of these were published by orthopedic surgeons who actually never researched physical methods of treatment for frozen shoulder, and do not have any clinical experience treating frozen shoulder by non-invasive means.

As I described above, the reflexive protective muscular spasm phenomenon is the result of severe sprain (pull) or strain that occurred suddenly in the momentum of physical effort. There is no need for muscular spasm to exist after the traumatic incident is over. Not only it leads to the development of muscular pathology and weakness, but also leaves inflamed connective tissue (e.g. ligaments and others) with a significantly decreased blood supply.

Gas Exchange in Connective Tissue

Unlike muscles ligaments and tendons do not have direct vascular blood supply. The molecular exchange in these regions are administered through diffusion. Diffusion (in its various forms) is a process that allows oxygen, nutrients, and other supplies to enter ligaments and tendons, while having carbon dioxide, and other waste products removed. The various supply molecules are released from neighboring blood vessels and make their way through diffusion to the target tissues. When a joint is sprained/strained and the muscles of the joint go into a spasm, the vasoconstriction of the vessels within the contracted muscles significantly hinders the diffusion process. The theory that swelling (an inflammatory condition) of neighboring ligaments is a protective phenomenon and should not be treated is unfounded. The inflammatory swelling of uninjured neighboring ligaments is the result of decreased amount of arterial blood supply (due to muscular spasm and the stasis of venous blood). Therefore, treating sprain/strain injuries is aimed at reducing muscular spasm, not only because we want to prevent muscular pathology and reduce the pain, but also because we help promote gas (and other materials) exchange in the tissues. In many cases, trauma related to sprain/strain causes partial tears in ligaments and tendons. So the restoration of the normal diffusion process is necessary for faster healing (formation of scar tissue) of partially torn tissues. Any inflammatory condition means existence of ischemia (decrease in blood supply) that produces pain and limitations in the range of motion. Stimulation of venous blood and lymphatic fluid drainage (reduction of edema) and relaxation of the muscles are stimulatory acts helping the healing process.

Summary

As a general rule, a greater number of treatments is required to treat frozen shoulder as compared to many other back and limb disorders. Treating rotator cuff syndrome promptly and adequately can prevent frozen shoulder from developing in the first place. The goals of the rotator cuff syndrome treatments are to eliminate muscular spasm, to increase blood supply to the tissues, and to eliminate trigger points. Should frozen shoulder develop as a result of post-surgical or post-fracture immobilization (sling or cast) of the shoulder region, explain to your client/patient that improvement is a function of time. It is very difficult to predict how many treatments may be needed for frozen shoulder. However, usually within the first 10 treatments patients experience less pain and have an increased range of motion.