Tendinitis and tendinosis

What is it?

Although the terms are often interchanged, tendinitis (or tendonitis) and tendinosis are two different conditions.  The tendon is a cord or band of fibrous tissue that connects muscle to bone.

Tendinitis literally means "inflammation of the tendon".  It is very rare - the tendon becomes painful and may become hot, red and swollen.  Tendinitis is an acute injury, which means that it is injured for a short period and, if managed correctly, settles quickly.

Tendinosis is much more common.  Rather than an inflammation, tendinosis occurs due to repeated trauma and ineffective healing of the tissue.  After an injury, the body attempts to heal the tendon by laying down new fibres.  However, with repeated trauma the healing process is disorganised and the tendon remains damaged.  For this reason, the tendon becomes weakened and more likely to tear.

Common sites for tendinosis

Rotator cuff tendinosis, golfer's elbow, tennis elbow, jumper's knee (patellar tendinosis), achilles tendinosis, adductor tendinosis

What does it feel like and how does it affect people?

While symptoms vary, both tendinosis and tendinitis generally involve localised pain at the site of injury, that may radiate into the associated muscle(s).

Tendinosis is generally most painful at the start of an activity.  Pain then settles gradually as the tendon warms up, only to return after activity.  Tendinitis is most painful during, or immediately after exercise.  Patients with either tendinitis or tendinosis often complain of stiffness in the morning, especially a day after exercising.

How can physiotherapy help?

As tendinitis is an inflammatory condition, it is often eased significantly by rest and anti-inflammatory medications.  Physiotherapy can help through providing supportive strapping or bracing to allow you to continue with your daily activities while still resting the injured tendon.

The treatment of tendinosis involves a special kind of exercise known as eccentric loading.  Your physiotherapist will teach you how to perform this exercise and prescribe a safe and effective amount for you to do.  Eccentric loading helps to reorganise the collagen fibres that make up your tendon, reduing pain and restoring tendon strength.  Your physiotherapist will also seek to identify and correct any biomechanical (body mechanics) abnormalities that are causing you to overload the specific tendon.