Types of Achilles Tendon Injuries

Achilles tendon injuries have the advantage of being relatively easy to diagnose: the Achilles tendon hurts. The most common Achilles tendon injuries are Achilles tendinosis (also known as Achilles tendinopathy) and Achilles tendon rupture. Achilles tendinosis is a soreness and stiffness, which can be increasingly severe. An Achilles tendon rupture, also known as an Achilles tendon tear, is the snapping or pulling apart of the Achilles tendon into two pieces. Achilles tendon ruptures can be full ruptures or partial ruptures. A physician may be required to distinguish between acute Achilles tendinosis and a partial Achilles tendon rupture. Tennis Leg is a rupture of the connection between the calf muscle and the Achilles tendon. Achilles tendonitis is an inflammation of the Achilles tendon: it is much less common than, but often confused with, Achilles tendinosis. Achilles tendons can also be lacerated or crushed.

 

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Achilles Tendon Injury Statistics

In 2002 there were an estimated 232,000 Achilles tendon sports injuries in the U.S.for individuals aged six and over. 109,000 prevented sports participation for between one future occasion and one month. 57,000 prevented participation for at least one month. 66,000 prevented participation for at least one month plus required emergency room treatment, a hospital stay, surgery, or therapy. The total number of Achilles tendon injuries is higher than 232,000 per year because of: a) non-sports Achilles tendon injuries, b) Achilles tendon sports injuries that do not interfere with sports participation, and c) some Achilles tendon injuries are suffered by children under the age of six. Note: Despite an extensive review of the medical and health research, we are unable to locate more up-to-date Achilles tendon injury statistics – if you are aware of more recent research, please contact: Editor {at} AchillesTendon {dot} com.

Achilles Tendinosis (Achilles Tendinopathy)

and the Achilles Tendon Pinch Test

Achilles tendinosis (also known as Achilles tendinopathy) is a soreness and stiffness that comes on gradually and continues to worsen until treated. It is a common injury among middle and long distance runners. The severity of Achilles tendinosis can be broken down into four stages, each of which can be measured in terms of how the Achilles tendon feels during exercise, the amount of stiffness and creaking, and Achilles tendon’s soreness to the touch (the Achilles tendon pinch test). The four stages, or grades, are:

Achillestendon-pinch-test-aStage 1. No pain during exercise, but there is some discomfort in the morning when first getting out of bed. The stiffness and creaking go away after a few minutes and are fine the rest of the day. Lightly pinching the Achilles tendon with the forefinger and thumb in the morning or after exercise will probably indicate soreness.

Stage 2. Pain during exercise or running, but performance is not affected. The stiffness and creaking continue to appear when first getting out of bed and continue to disappear shortly afterward. Lightly pinching the Achilles tendon with the forefinger and thumb in the morning or after exercise will indicate soreness.

Stage 3. Pain during exercise or running that is detrimental to performance. The stiffness and creaking continue to appear when first getting out of bed, but may continue for some time and reappear at other points during the day. Lightly pinching the Achilles tendon with the forefinger and thumb in the morning or after exercise will indicate soreness.

Stage 4. Hurts too much to exercise or run. The stiffness and creaking continue to appear when first getting out of bed, but may continue for most of the day. Lightly pinching the Achilles tendon with the forefinger and thumb at almost any time of day will indicate soreness.

Achilles Tendinosis vs. Achilles Tendonitis

Achilles Tendinosis and Achilles Tendonitis (often spelled Achilles Tendinitis) are often confused. In the late 1990’s sports medicine researchers discovered that the vast majority of people with Achilles tendon pain (aside from those with Achilles tendon ruptures) have Achilles tendinosis, rather than Achilles tendonitis. Achilles tendonitis is an inflammation: the Achilles tendon becomes filled with inflamed cells. With Achilles tendinosis: a) there is no evidence of inflammation, b) the injured areas of the Achilles tendon have lost their normal glistening appearance, and c) microscopic analysis of the collegen and related fibers that make up the Achilles tendon reveal that the cells are disorganized, degenerated, and scarred.

Achilles Tendinosis vs. Achilles Tenosynovitis

Achilles Tenosynovitis (or Achilles teno synovitis) is similar to Achilles tendinosis, but occurs in the Achilles tendon sheath, rather than in the Achilles tendon itself. Achilles Tenosynovitis causes fibrosis and scaring that can restrict the Achilles tendon’s motion within the Achilles tendon sheath. Achilles Tenosynovitis can occur in parallel with, or lead to Achilles tendinosis.

Tennis Leg

Tennis leg is a musculotendinous junction rupture: a stretch, tear, or complete rupture of the connection between the gastrocnemius (calf) muscle and the Achilles tendon. Tennis and soccer players over 40 are the most frequent sufferers. The injury often occurs when lunging or pushing off one leg to get to a wide ball or serve. It feels like being kicked in the leg from behind: the tennis leg sufferer feels an instantaneous severe sharp pain, turns around to see who kicked them, only to discover that no one is there. Note: “Tennis Leg” is an informal term that is sometimes applied to stretches, tears, or ruptures of the calf itself, rather than to the Achilles-gastrocnemius junction.

MidPoint and Insertional

Midpoint Achilles tendon injuries are more common than insertional Achilles tendon injuries. Midpoint means mid way between the top and bottom of the Achilles tendon. An Insertional Achilles tendon injury is an injury at the bottom of the Achilles tendon, where the Achilles tendon connects with (inserts into) the heel bone. Non-insertional Achilles tendon injury means an injury to any part of the Achilles tendon except the Achilles tendon – heel bone connection.

Achilles Tendon Laceration and Crushing

Achilles tendons can be partially cut or completely severed by strong sharp edges (i.e. lawn mower blades) or crushed by heavy objects (something large falling on the Achilles tendon). These types of injuries are often complicated and involve damage to multiple parts of the foot and lower leg.

Achilles Tendon Rupture

Achilles tendon rupture is a partial or complete tear of the Achilles tendon. It comes on suddenly, sometimes with a popping sound, and can be debilitating. A full rupture is more severe, but less common, than a partial rupture.

A full rupture tears the Achilles tendon apart, so that it no longer connects the calf muscles (soleus and gastrocnemius) to the heel bone. If it is a full rupture, then lightly pinching the Achilles tendon with the forefinger and thumb will reveal a gap in the Achilles tendon.

Partial and full Achilles tendon ruptures are most likely to occur in sports requiring sudden stretching, such as sprinting and racquet sports. Partial Achilles tendon tears are also common among middle and long distance runners. Achilles tendon ruptures can happen to anyone, but are most likely to occur to middle age athletes who have not been training or who have been doing relatively little training.

Calf Squeeze test, Simmonds test, Simmonds calf squeeze test, Thompson test, and Simmonds-Thompson test for Achilles Tendon Rupture

The calf squeeze test is the primary screening procedure for Achilles tendon rupture.  The calf squeeze test is also known as the Simmonds test, Simmonds squeeze test, Thompson test, and the Simmonds-Thompson test.  There are two muscles in the calf:  the soleus and the gastrocnemius.  Both are connected to the heel bone by the Achilles tendon.  The test determines whether or not a person has suffered a full Achilles tendon rupture of the soleus muscle – heel bone connection.  The calf squeeze does not test for the less common Achilles tendon rupture of the gastrocnemius muscle – heel bone connection, nor does it test for a partial Achilles tendon rupture or Achilles tendinosis.

To perform the test, the person being tested lies down on their stomach, or kneels.  In either case the foot is pointed downward, there is no weight on the calf or foot, and the foot is hanging freely.  When the calf muscle is gently squeezed, the foot will either involuntarily point or it will not.  If the foot points, great: the Achilles tendon is connecting the soleus muscle with the heel bone.  If the foot does not point, the connection between the soleus muscle and the heel bone has been fully ruptured.

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Partial Achilles Tendon Rupture vs. Achilles Tendinosis

Unfortunately, the soreness felt when lightly pinching a partially torn Achilles tendon with the forefinger and thumb is the same as the soreness felt when lightly pinching an Achilles tendon with Achilles tendinosis.

Also, to confuse things a little further: some heel bursitis symptoms are similar to some Achilles tendinosis symptoms. As with any injury, it is best to consult a physician. For information on physicians whose specialties include the diagnosis and treatment of Achilles tendon injuries see Specialists.

Why So Many Achilles Tendon Injuries?

It is not yet known why the Achilles tendon is especially susceptible to degeneration. Some believe that it may be due to the whipping action or bowstring effect caused by ankle pronation, some believe it is the Achilles tendon’s relatively weak blood supply, and some believe that it may be the combination and frequency of eccentric shortening when the heel hits the ground followed rapidly by concentric contraction when the toes push off. More research would be helpful.

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