Symptoms and Causes:

“...the biggest contributor to chronic achilles tendonitis is ignoring pain.”

Achilles tendonitis is the bane of many runners. You should not allow this to turn into a chronic and troubling malady leading to moans about how it will never end, contributing to roadsides strewn with air cushioned clad runners, all with ice packs attached to their heels. First, we will review some basic information about the achilles tendon.

The achilles tendon is the connection between the heel and the most powerful muscle group in the body. This has long been known as a site which is prone to disabling injury. Forces up to 12 times body weight (9kN) may arise during sprinting. This tendon is named after Achilles, who according to myth, was protected from wounds by being dipped in a magical pond by his mother. She held him by the heel, which was not immersed, and later died by an arrow wound in his heel. Although injuries to this area must have been known for more than 2,000 years, it was first reported in the medical literature by Ambroise Paré only 400 years ago.

The achilles tendon joins three muscles: the two heads of the gastrocnemius and the soleus. The gastrocnemius heads arise from the posterior portions of the femoral condyles. The soleus arises from the posterior aspect of the tibia and fibula.

The gastrocnemius is a muscle that crosses three joints: the knee, the ankle, and the subtalar joint. The functioning of these joints and influence of other muscles on these joints has a significant effect on the tension that occurs within the achilles tendon. As an example tight hamstrings impact the functioning of the ankle joint, the subtalar joint, and increase tension in the achilles tendon. The soleus does not cross the knee and is a biarticualar muscle.

The plantaris is a nearby muscle that has its separate tendon. It arises from the lateral condyle of the femur. It has a thin tendon that passes between the gastrocnemius and soleus and inserts into the calcaneus. When this musclculotendinous structure is injured it is frequently felt as a "pellet shot" in the back of the leg. The tear is usually about eight inches below the knee joint.

The bulk of the achilles tendon inserts into the posterior superior third of the calcaneus. Some fibers course distally and continue to where portions of the plantar fascia insert into the plantar aspect of the calcaneus.

The achilles tendon does not have a rich blood supply. The blood supply has been found to be weakest at a point between 2 and 6 cm above its insertion into the calcaneus. (Although Astrom found with Doppler flow measurements the least vascularity at the insertion.) It is not invested within a true tendon sheath. A paratenon composed of other soft tissue surround it. The outer layer is a portion of the deep fascia, the middle layer is called the mesotenon and the inner layer is contiguous with a thin layer surrounding the tendon itself (epitenon). The blood supply to the proximal portion of the tendon comes from the branches of the muscles themselves. The distal portion is supplied by branches from the tendon-bone interface. The mesotenon supplies the major blood supply to the Achilles tendon.

Contributing Factors

There are several factors that can contribute to achilles tendonitis. First, you should know that the biggest contributor to chronic achilles tendonitis is ignoring pain in your achilles tendon and running through the pain of early achilles tendonitis. If your achilles tendon is getting sore it is time to pay attention to it, immediately.

Sudden increases in training can contribute to achilles tendonitis. Excessive hill running or a sudden addition of hills and speed work can also contribute to this problem. Two sole construction flaws can also aggravate achilles tendonitis. The first is a sole that is too stiff, especially at the ball of the foot. (In case you are having difficulty locating the "ball" of your foot, I mean the part where the toes join the foot and at which the foot bends) If this area is stiff than the "lever arm" of the foot is longer and the achilles tendon will be under increased tension and the calf muscles must work harder to lift the heel off the ground.

The second contributing shoe design factor which may lead to continuing achilles tendon problem is excessive heel cushioning. Air filled heels, while supposedly are now more resistant to deformation and leaks are not good for a sore achilles tendon. The reason for this is quite simple. If you are wearing a shoe that is designed to give great heel shock absorption what frequently happens is that after heel contact, the heel continues to sink lower while the shoe is absorbing the shock. This further stretches the achilles tendon, at a time when the leg and body are moving forward over the foot. Change your shoes to one without this "feature".

Of course another major factor is excessive tightness of the posterior leg muscles, the calf muscles and the hamstrings may contribute to prolonged achilles tendonitis. Gentle calf stretching should be performed preventatively. During a bout of acute achilles tendonitis, however, overly exuberant stretching should not be performed.

Treatment

The first thing to do is to cut back your training. If you are working out twice a day, change to once a day and take one or two days off per week. If you are working out every day cut back to every other day and decrease your mileage. Training modification is essential to treatment of this

“...Training modification is essential.”

potentially long lasting problem. You should also cut back on hill work and speed work. Post running ice may also help. Be sure to avoid excessive stretching. The first phase of healing should be accompanied by relative rest, which doesn't necessarily mean stopping running, but as I am emphasizing, a cut back in training. If this does not help quickly, consider the use of a 1/4 inch heel lift can also help. Do not start worrying if you will become dependent on this, concentrate on getting rid of the pain. Don't walk barefoot around your house, avoid excessively flat shoes, such as "sneakers", tennis shoes, cross trainers, etc.

In office treatment would initially consist of the use of the physical therapy modalities of electrical stimulation, (HVGS, high voltage galvanic stimulation), and ultrasound. Your sports medicine physician should also carefully check your shoes. A heel lift can also be used and control of excessive pronation by taping can also be incorporated into a program of achilles tendonitis rehabilitation therapy. Orthotics with a small heel lift are often helpful.

Exercises to Avoid

Excessive stretching is not good for your achilles tendon. The stretch that I most often recommend is the "wall stretch". I do not recommend the "stair stretch", the "incline stretch", or the "put a towel around your feet and pull up until it hurts stretch". If any of these are working for you, that's great, you don't need any advice. In most cases, for the patients I see, these stretches put too much tension on the already tender achilles tendon. Contracting the muscle when it is in a stretched position, as initial therapy of an injured achilles tendon is not a good thing.

Treatment Outline:

  1. Relative rest (see above)
    1. Cut back mileage
    2. Lower intensity
    3. Avoid hills, speedwork, plyometrics
  2. Avoid over-stretching
    1. Gentle stretch after warm-up
    2. Start with Straight leg calf stretch, build up much later to bent leg, consider eccentric stretch later.
  3. Ice Massage
    1. 10 to 20 minutes after exercise
  4. NSAIDs
    1. Alleve, Motrin, etc. 10 - 14 days.
  5. Check Running Shoes
    1. Replace if heel is worn
    2. Replace if excessive heel shock absorption (soft air sole cushion, excessive gel shock absorption)
    3. Replace if shoe is excessively stiff at the "break point" (ball of foot).
  6. Physical Therapy Modalities
    1. HVGS (electrical stimulation)
    2. Ultrasound
    3. Exercise instruction: Strength and flexibility

Current Concepts

While Achilles tendon problems are widespread, the terminology used to describe them is often inaccurate and is undergoing a significant transition. First to be precise we must consider where along the course of the tendon does the problem exist. This may be in one of three main areas:

  1. Insertion
  2. Musculo-tendinous Juncture
  3. Non-insertional (main body of tendon)

While the term that most people use and that most individuals will search for on the web is "tendonitis", most Achilles tendon problems could better be called a tendinopathy and more specifically a tendinosis and are a non-inflammatory problem of the tendon. Inflammatory cells are not found on microscopic examination.

Clinically there may be two differing entities in acute achilles tendinopathy:

  • Peritendonitis
    • Inflammation in the tissue surrounding the tendon
    • Often 2 - 6 cm above insertion
    • Possible crepitus with long standing injury (paratenon with fibrin exudate)
    • In chronic tendinopathy approximately 20% of the injured peritendinous area are scar forming myofibroblast cells.
  • Tendinosis
    • Impairment of circulation with resulting damage to tendon structure
    • Focal areas of tendon degeneration

Much future research and better understanding of these injuries is needed. In spite of the vagaries of scientific understanding of these entities a successful approach using training modification, stretching, strengthening and appropriate return to exercise may be undertaken. At this time there are few significant clinical studies with valid results for treatment. There is often disagreement on approach and much is likely to be changed in the future. At this point treatment and treatment recommendations for this problem remain an art practiced with varying degrees of success. When evaluating new research, it is hard to recommend major paradigm changes in thought and recommendations based on studies of fewer then 20 cases or even 50 cases.

     

 

Achilles Tendon Ruptures

The achilles tendon is the connection between the heel and the most powerful muscle group in the body. This has long been known as a site prone to disabling injury. It is named after Achilles, who according to myth was protected from wounds by being dipped in a magical pond by his mother. She held him by the heel, which was not immersed, and later died by an arrow wound in his heel. Although obviously, injuries to this area must have been known for more than 2,000 years, it was first reported in the medical literature by Ambroise Paré only 400 years ago.

The achilles tendon joins three muscles: the two heads of the gastrocnemius and the soleus. The gastrocnemius heads arise from the posterior portions of the femoral condyles. The soleus arises from the posterior aspect of the tibia and fibula.

The gastrocnemius is a muscle that crosses three joints: the knee, the ankle, and the subtalar joint. The functioning of these joints and influence of other muscles on these joints has a significant effect on the tension that occurs within the achilles tendon. As an example tight hamstrings impact the functioning of the ankle joint, the subtalar joint, and increase tension in the achilles tendon. The soleus does not cross the knee and is a biarticualar muscle.

The plantaris is a nearby muscle that has its separate tendon. It arises from the lateral condyle of the femur. It has a thin tendon that passes between the gastrocnemius and soleus and inserts into the calcaneus. When this musclculotendinous structure is injured it is frequently felt as a "pellet shot" in the back of the leg. The tear is usually about eight inches below the knee joint.

The bulk of the achilles tendon inserts into the posterior superior third of the calcaneus. Some fibers course distally and continue to where portions of the plantar fascia insert into the plantar aspect of the calcaneus.

The achilles tendon does not have a rich blood supply. It is not invested within a true tendon sheath. A paratenon composed of other soft tissue surround it. The outer layer is a portion of the deep fascia, the middle layer is called the mesotenon and the inner layer is a thin layer. The blood supply to the proximal portion of the tendon comes from the branches of the muscles themselves. The distal portion is supplied by branches from the tendon-bone interface. The mesotenon supplies the major blood supply to the Achilles tendon.

The actual cause of rupture of the Achilles tendon is not known. The mechanism of injury is a force that increases the tensile force in the tendon beyond its tensile strength. This may be visualized as a dorsiflexion force at the foot or concomitantly a forward motion of the tibia over the foot while the calf muscles are contracting. As stated the force must exceed the tensile strength of the tendon. A forceful stretch of the tendon or a contraction of the muscles may create this force. Most often it is a combination of the two forces. Many researchers feel that some degeneration is present in the tendon prior to rupture. The usual site of rupture is approximately 2 to 6 centimeters proximal to the insertion in the calcaneus. This is also the portion of the tendon that has the poorest blood supply. Occasionally ruptures occur at the tendon-bone interface or musculo-tendinous junction. Since vascularity decreases with age, this frequently occurs in the ageing athlete. A weakening of the Achilles tendon has been observed following intra- tendinous steroid injection. Therefore, injections of steroids are not recommended at this location. Diseases associated with a possibly increased incidence of tendon rupture include gout, systemic lupus erythematosis, rheumatoid arthritis and tuberculosis.

Diagnosis

Physical examination of the site of a recent rupture may reveal a palpable gap at the site of the rupture. Swelling will be seen. The most frequently described clinical test is called the Thompson test. With the patient lying prone (on his stomach) the calf is squeezed. The foot will plantarflex in a patient who does not have a completely torn Achilles tendon. The foot will not plantar flex when the Achilles tendon is completely torn. An MRI will accurately reveal the extent of the tear. Diagnostic ultrasound is also used to assist in the diagnosis of a torn Achilles tendon.

An MRI image of a partially torn Achilles Tendon is available on line at the site of The Graduate Hospital Imaging Center.

Treatment

Complete tears of the Achilles tendon, in the athlete, are usually treated with surgical repair followed with up to 12 weeks in a series of casts. Partial tears are sometimes treated with casting for up to 12 weeks alone, and sometimes are treated as are the complete tears, with surgery and casting. A heel lift is usually used for 6 months to one year following removal of the cast. Rehabilitation to regain flexibility and then to regain muscle strength are also instituted following removal of the cast.

 

Selected References:

  1. Current Concepts Review: Achilles Tendinopathy. Paavola et. al. JBJS 84-A: 2062-2076. November 2002.
  2. In vivo measurements of Achilles Tendon Forces In Man. Komi et. al. Med Sci Sports Exer 1984; 16:165-6.
  3. Biomechanical Loading Of Achilles tendon during normal locomotion. Clin Sports Med. 1992;11:521-531.
  4. Ruptured Achilles Tendons are more degenerated then Tendinopathic Tendons. Tallon et. al. Med Sci Sports Exer 2001; 33:1983-1990.
  5. Blood Flow in the Human Achilles Tendon. Astrom M. et. Westlin N.. J. Orthop Res. 1994;12:246-252.
  6. Classification of Achilles Tendon Disease. Puddu G. et. al.. Am J Sports Med. 1976; 4:145-150.
  7. Paavola M: Long-term prognosis of patients with Achilles tendinopathy. Am J Sports Med 2000, 28:634-641
  8. Treatment of Acute Achilles Tendon Ruptures A Systematic Overview and Metaanalysis. Bhandari, M; Guyatt, G, et.al. Clinical Orthopedics and Related Research (400) July 2002 pp 190-200