What is a Frozen Shoulder?

Adhesive Capsulitis is the medical term for “Frozen Shoulder Syndrome” – sometimes abbreviated to FSS.  This is a condition which affects the ability to move the shoulder, and usually only occurs on one side.  Sometimes (approximately 1 in 5) the problem can spread to the other shoulder.  The medical term literally describes what is seen in this condition – adhesive meaning sticky, and capsulitis meaning inflammation of the joint capsule.  It is thought that a lot of the symptoms are due to the capsule becoming inflamed and “sticking”, making the joint stiff and difficult to move.

This is not the same as arthritis, and no other joints are usually affected.

Who does this affect?

Frozen Shoulder is extremely uncommon amongst young people, and is almost always found in the 40+ age group, usually in the 40-70 age range.  Approximately 3% of the population will be affected by this, with slightly higher incidence amongst women, and is five times more common in diabetic.

What causes a frozen shoulder?

There are two classifications of frozen shoulder syndromes:

• Primary - No significant reason for pain/stiffness
• Secondary - As a result of an event such as trauma, surgery or illness

It is not known exactly what causes this problem, however it is thought that the lining of the joint (the capsule) becomes inflamed, which causes scar tissue to form.  This leaves less room for the humerus (arm bone) to move, hence restricting the movement of the joint. 

The increased prevalence amongst diabetics (particularly insulin-dependent diabetics) may be due to glucose molecules sticking to the collagen fibres in the joint capsule, which causes stiffness.  For this reason, diabetics are more likely to have both shoulders affected. 

Hormonal changes may be responsible for the higher incidence amongst women, particularly due to the increased prevalence around the menopausal period.

Some studies have shown that poor posture, particularly rounded shoulders, can cause shortening of one of the ligaments of the shoulder, which may also contribute to this condition.  Also, prolonged immobility (such as after a fracture) may cause this condition to develop.

What are the symptoms?

This condition has been described in three phases, so the symptoms will differ depending on the phase of the condition

The Painful Phase

• Gradual onset of aching shoulder
• Developing widespread pain, often worst at night and when lying on the affected side
• This phase can last anywhere between 2-9 months

The Stiffening Phase

• Stiffness starts to become a problem
• Pain level usually does not alter
• Difficulty with normal daily tasks such as dressing, preparing food, carrying bags, working
• Muscle wastage may be evident due to lack of use
• This stage can last between 4-12 months

The Thawing Phase

• Gradual improvement in range of movement
• Gradual decrease in pain, although it may re-appear as stiffness eases
• This stage can last between 5-12 months

Please see the Virtual Sports Injury Clinic for more information on how to treat a Frozen Shoulder and other shoulder injuries