High cushion running shoes may feel good, but they are actually damaging to the lower leg, especially to the Achilles tendon. Over the past decade, there have been revolutionary findings about the damaging effects of running shoes with cushioned support and motion control features.
High Cushion Running Shoes Bad for Achilles Tendon
Cushioned running shoes exaggerate forefoot eversion (foot tilts outward) at touchdown, which increases pronation. In this well-documented phenomenon, shod-induced prolonged pronation triggers high tibial rotational forces and a wringing-like action to the Achilles (Clement et al. 1984).
Similar findings were reported by Donoghue et al. (2008) who compared lower leg kinematics during barefoot and shod running in runners with a long history of Achilles injury to healthy runners.
- The researchers found that runners with Achilles injury had greater forefoot eversion during stance, which was exaggerated in cushioned running shoes.
- Cushioned running shoes consistently exaggerated the maximum and range of motion values associated with Achilles injury.
- Shod runners had the largest measure of forefoot eversion (10.52°) than the barefoot runners (8.21°).
The findings imply that cushioned running shoes unleash a bad mix of functional and structural misalignments of the foot/ankle complex during running and these shoes burdens a runner with additional kinematic demands due to undesirable levels of pronation, increasing the risk of Achilles injury.
The Take Home Message
Because of the lack of mechanical interference from shoe cushioning, barefoot running allows for more natural movement patterns of the foot that defy abnormal pronation. Since proprioception is heightened, barefoot running also improves static alignment of the lower leg, thereby reducing kinematic variables related to Achilles injury. Research also finds that pure minimalist shoes (barefoot-like running shoes) are not expected to exaggerate pronation like cushioned running shoes because they lack compressible materials and allow for more proprioceptive feedback.
From this, we can no longer accept cushioned running shoes in roles traditionally assigned to treat Achilles injury because their contributions are pervasive and less worthy of helpful.
More From Run Forefoot:
Clement DB, Taunton JE, Smart GW (1984) Achilles tendonitis and peritendinitis: Etiology and treatment. American Journal of Sports Medicine 12(3): 179–184.
Donoghue et al. Lower limb kinematics of subjects with chronic achilles tendon injury during running. Res Sports Med, 2008;16:23-38.
Hamill J, Haddad JM, van Emmerik REA (2006). Overuse injuries in running: Do complex analyses help our understanding? In H. Schwameder, G. Strutzenberger,V.Fastenbauer, et al. (Eds.) XXIV International Symposium on Biomechanics in Sports (pp. 27–32). Salzburg, Austria: International Society of Biomechanics in Sports.
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.