Heel Striking Running Results in Less Energy Supply of the Achilles

Heel striking running reduces elasticity effectiveness of the Achilles tendon. What is elasticity effectiveness? It is essential to running performance because it is energy supplied in a passive form. You can think of it as free energy that we don’t need to work very hard for. That is, less effort is required to store and use it, but this feature of the Achilles tendon is optimized with forefoot striking, not heel striking when you run.

Heel Striking Running Results in Less Energy Supply of the Achilles

Heel Striking Running Results in Less Energy Supply of the Achilles

Heel striking mechanically reduces elastic effectiveness of the Achilles tendon, resulting in greater muscular effort and energy expenditure.

  • at heel strike, the foot strikes the ground in front of the knee while the knee is unbent and less energy is absorbed by the tendons as a consequence
  • increasing running speed while heel striking increases compressive forces on the Achilles tendon, impairing elasticity effectiveness
  • heel strike running increases ground contact time which may also reduce stretch-potential of elastic tissues

Forefoot Running, an Energy Saver!

Habitual forefoot runners run with less muscular effort, especially at faster speeds, because they make greater use of the elasticity effectiveness of the Achilles tendon.

The energy-saving mechanism of forefoot running at the level of the tendon may suggest why elite runners land on the forefoot when running, rather than the heel.

  • elastic effectiveness of the Achilles tendon accounts for 35% of mechanical energy needed in running
  • because the foot lands under the knee as the knee is slightly flexed, forefoot strike running reduces ground contact time, increasing stretch-potential of elastic tissues thereby enhancing elasticity effectiveness

The Take Home Message

Could it be that heel striking is a mechanical failure in running which distorts the natural function of the Achilles tendon, and as a consequence, result in poor running economy?

It seems that the elastic effectiveness of the Achilles tendon jives better with the mechanics a forefoot strike compared to a heel strike.  That is, forefoot strike running mechanics may provide optimal conditions to enhance the natural spring-like property of the Achilles.

Benefits of Forefoot Running:


References:

Hunter et al., 2011. Tendon length and joint flexibility are related to running economy. Med Sci Sports Exerc. 43(8); 1492-9.

Run forefoot, because you are faster than you think!

Bretta Riches

"I believe the forefoot strike is the engine of endurance running..."

BSc Neurobiology; MSc Biomechanics candidate, ultra minimalist runner & founder of RunForefoot. I was a heel striker, always injured. I was inspired by the great Tirunesh Dibaba to try forefoot running. Now, I'm injury free. This is why I launched Run Forefoot, to advocate the health & performance benefits of forefoot running and to raise awareness on the dangers of heel striking, because the world needs to know.
Bretta Riches

P.S. Don't forget to check out the Run Forefoot Facebook Page, it's a terrific place to ask questions about forefoot running, barefoot running and injury. I'm always happy to help!

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