Eccentric Achilles Tendon Strengthening

Healthy caucasian woman keeping fit in the winter by stretching before jogging in a snow filled city
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The most common injuries related to the Achilles tendon are Achilles tendonitis (microtears in and around the tendon) and Achilles tendon rupture (a partial or full tear that results in instant pain and loss of movement).

If you participate in sports that require strong forefoot push-offs—think tennis or basketball—it's important to keep your Achilles tendon strong and flexible. Recommendations include:

Some experts believe that eccentric strengthening of the Achilles tendon, gastrocnemius muscle, and soleus muscle may reduce the risk of Achilles tendonitis and calf strain.

Our tendons are made up of mostly type I collagen. This type of tissue gets stiffer and stronger under tension. Because the eccentric muscle contractions cause the muscle fiber to generate more tension than either concentric or isometric contractions, eccentric muscle contractions appear to be associated with greater muscle strengthening, which may protect the Achilles tendon.

Some argue that the benefit may be due to the stretching of the muscle during eccentric exercise and a corresponding lengthening of the muscle-tendon unit that results in less strain during ankle joint motion and fewer injuries.

While we may not know with certainty if the benefit of this eccentric exercise is due to the strengthening or the stretching component, it has been shown to effectively treat Achilles tendinitis when performed properly.

Eccentric Strengthening Exercise

This exercise is based on performing three sets of 15 repetitions on the affected leg twice per day, seven days per week, for 12 weeks. It should be performed with moderate, but not disabling, pain.

  1. Warm up with gentle stationary cycling, walking, or marching in place for several minutes.
  2. Stretch your calf muscles.
  3. Stand on the balls of your feet on the edge of a sturdy box or step, keeping your heels free.
  4. Maintain control at all times and slowly lift up as high as you can on both toes.
  5. Move your weight to the foot on the affected side and slowly begin to lower yourself (this is the eccentric contraction phase) until your heels are just below the step.
  6. Shift your weight back to both feet and return to the start (top) position and repeat 10 to 15 times.
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3 Sources
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  1. University of Wisconsin-Madison School of Medicine and Public Health. Achilles tendon problems. Updated June 26, 2019.

  2. Hody S, Croisier JL, Bury T, Rogister B, Leprince P. Eccentric muscle contractions: Risks and benefits. Front Physiol. 2019;10:536. doi:10.3389/fphys.2019.00536

  3. van der Plas A, de Jonge S, de Vos RJ, et al. A 5-year follow-up study of Alfredson's heel-drop exercise programme in chronic midportion Achilles tendinopathy. Br J Sports Med. 2012;46(3):214-8. doi:10.1136/bjsports-2011-090035