Why Heel Striking is Bad for the Achilles

Heel striking when running is a big contributor to Achilles injury because the mechanical elements of landing heel-first was found to be pain and injury-predisposing on the tendon as compared with forefoot running. Here was the confirmation:

In order to land heel-first, the front of your foot (forefoot) must lift up (dorsiflexion), shown below:

Is Heel Striking Bad for the Achilles? — Dorsiflexion is when the front of the foot lifts up, and is a common mechanical movement of the foot in heel strike running because the forefoot needs to lift up to allow the heel to strike the ground first. The problem with this is it was found to increase tension and stretch force on the Achilles, leading to pain and swelling.

A study in the journal, Research in Sports Medicine, noticed that all runners with an Achilles injury lifted their forefoot back upon and at touchdown. This is in accordance to other assessments in that a study in The American Journal Sports Medicine, reported that the greater the dorsiflexion (forefoot lifting) at landing when running, the greater the excursion of the foot, meaning the foot pushed away from its neutral line which increased strain and mechanical load on the gastrocnemius and Achilles tendon.

Why Forefoot Running is Better for the Achilles

Of significance, it’s been well-reported that the mechanical properties of forefoot running is a natural stabilizing reinforcer on the foot. This is largely responsible for helping improve the odds of avoiding Achilles pain and injury since the foot moves around less which cancels out higher levels of stress and strain on the tendon. Here are the main reasons for this:

For one, the forefoot doesn’t lift up (no dorsiflexion) at landing, rather the forefoot points down towards the ground, allowing the forefoot to strike the ground before the heel, shown below:

Best Running Technique for Achilles Tendinitis — Forefoot striking when running plays a dominant role in safeguarding the Achilles because there’s reduced dorsiflexion at landing which has a strong stabilizing effect on the foot/ankle complex, and reduces stress off the Achilles.

For another, the foot spends a shorter amount of time on the ground in forefoot running, thereby preventing wasted movement of the foot which greatly unstresses the Achilles. Not to mention, there are less all-around force components acting across the Achilles in forefoot running than heel strike running!

The Take Home Message

The foot is less capable of maintaining postural stability in heel strike running, which is the leading cause of Achilles injury, and is ultimately, a revealing indicator that foot strike pattern really does matter in running. This is why forefoot striking is the better answer to avoiding Achilles injury because the foot does not alter from its neutral trajectory since the foot is more stable at pinning down, and there’s less net forces, too, thereby allowing you to be on the safer side of running.

The final piece of good news is here’s more detailed evidence telling us why the Achilles is significant less prone to injury with forefoot running than heel striking:

Forefoot Running Improves the Elastic Properties of the Achilles Tendon

Forefoot Running Reduced Achilles Injury By Reducing Heel-Whipping

Forefoot Running Reduces Brake Loads and Compressive Forces on the Achilles

More From Run Forefoot:

References:

Donoghue et al. Lower limb kinematics of subjects with chronic Achilles tendon injury during running. Res Sports Med, 2008;16:23-38.

Mahieu et al. Intrinsic risk factors for the development of achilles tendon overuse injury. Am J Sports Med, 2006; 34(2):226-234
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