The role of eccentric exercise in treating tendinosis.

At AMAA's 16th Annual Sports Medicine Symposium at the Marine Corps Marathon, a panel presented the etiology, diagnosis, and recommended treatments for tendinopathy. The following is an informational article an the topic and sample patient handout provided for the program packet by presenter MAJ Anthony I. Beutler, MD. Dr. Beutler is Chief of the Injury Prevention Research Laboratory and Assistant Professor at the Department of Family Medicine at the Uniformed Services University of the Health Sciences in Bethesda, Maryland.

If you'd like a list of the references mentioned in the article, please contact Dr. Beutler at [e-mail].

Background

Alfredson first reported success using heavy-load eccentric training to treat chronic Achilles tendinosis in 1998. From 1998 to 2002 only five articles appeared in the scientific literature regarding eccentric training. But in 2006 thirteen articles were published describing eccentric exercise treatment for varied types of tendinosis. As of July 1, at least 23 such articles had been published in 2007. Given this information explosion, what do we know about eccentric exercise and its role in the treatment of chronic tendinopathies?

What is Eccentric Exercise?

The term eccentric exercise refers to muscular activation during muscle lengthening (e.g., the biceps is activated eccentrically when a dumbbell is slowly lowered from the shoulder to the waist). For decades, conventional wisdom held that tendinosis patients should scrupulously avoid eccentric exercise for fear of rupturing the diseased tendon; however, as proven by Alfredson and others from 1985 to 2004, eccentric exercise seems to be beneficial. It normalizes peritendinous blood flow, improves tendon histology and morphology, and most importantly, decreases clinical tendinosis symptoms.

Mechanism of Therapeutic Action

The exact mechanisms by which eccentric exercise exerts its beneficial effects are incompletely understood. Tendinosis is a non-inflamatory, degenerative tendon condition. Eccentric exercise appears to decrease the characteristic neovascularization found in degenerative tendons. It is not known whether eccentric exercise reduces neovascularization directly by mechanically destroying neovessels or indirectly through alterations in vascular growth factors. It is also possible that eccentric exercise may directly stimulate collagen synthesis pathways.

What Does the Evidence Show?

Many questions still exist regarding optimal frequency, duration, and loading of eccentric exercise. Also unclear is the question of whether athletes can continue to train and compete while undergoing eccentric rehabilitation for symptomatic tendinosis. But we do know that strong clinical evidence shows that eccentric exercise treatment is highly effective for Achilles tendinosis and patellar tendinosis (jumper's knee). Moderate evidence supports its efficacy in tendinosis at the elbow (tennis elbow) and smaller studies show benefit in other wrist tendinopathies.

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RELATED ARTICLE: Patient Handout: Heel Drop Exercises for Achilles Tendinopathy

Exercise 1:

1. Wearing good shoes that have minimal flexibility in the sole, stand on the edge of a step and let your heels hang off.

[FIGURE A OMITTED]

2. Using both legs, push up onto your toes (Figure A).

3. Lift your left foot up so that you stand on the toes of your right foot only. Keep your right knee straight.

4. Using only your right leg, slowly lower your heel towards the ground (Figure B). Be sure to lower yourself in a controlled fashion.

5. Replace your left foot onto the step. Push up with both legs to return to starting position (Figure A). Perform 15 repetitions with the right leg.

6. Repeat the above using the left leg. Perform two sets of 15 repetitions for both the right and left legs.

Exercise 2:

1. Stand on the step again, up on your toes (Figure A), and lift your left foot up.

[FIGURE B OMITTED]

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2. Lower your heel to the ground slowly using only your right leg, but this time keep your right knee bent (Figure C).

3. Perform 15 repetitions with the right leg and then repeat with the left leg. Perform two sets of 15 repetitions for both right and legs.

Tips:

Maintain good alignment. Keep your knees, hips, and ankles positioned with one over the other. Avoid excessive trunk flexion (Figure D).

Your legs will be sore. This is actually good; it's part of the healing process. In a couple of weeks you will notice that your legs are not sore anymore after performing the exercises. When this happens, you'll want to increase the resistance by using a weight sled in the gym, putting weights in a backpack, or holding weights (this will make your legs sore again).

During the first four to six weeks of exercises, you should not run or play sports. During the last four to six weeks, your doctor may allow you to return to some of these activities.