Footwear and Achilles Tendons

Footwear and Achilles Tendon Injuries

Achilles tendon injuries and footwear are related in three ways: correctly fitting footwear can be a major factor in preventing Achilles tendon injuries, recovering from Achilles tendon injuries, and preventing the re-occurrence of Achilles tendon injuries. Unfortunately, the reverse is just as true: incorrect footwear can increase the likelihood of Achilles tendon injuries, delay recovery, and increase the chance of a re-occurrence

An Achilles tendon injury is usually a sign that footwear changes should be made.  Better fitting shoes and sports shoes often make a huge difference to the Achilles tendons.  A good fit means a lot more than just the right shoe size and width; it means the correct arch, cushioning, firmness, height, and heel height.  Keep shoes that fit well, get rid of old worn out shoes and shoes that do not have a good fit.

 

Achilles Tendon il-shoes

Achilles Tendon Shoe and Sports Shoe Guidelines

In addition to the right shoe size and width for a snug fit, the following factors are of particular importance to the Achilles tendon:

Good Arch Support

Flat feet (feet with low arches) and high arched feet are each associated with a higher likelihood of Achilles tendon injuries.  The shoe’s arch support should match the foot’s arch.  Feet with low, normal, and high arches all benefits from adequate arch support, either built into the shoe or inserted.

Bend at the Balls of the Feet

Shoes should bend at the same place your foot bends.  Your foot bends at the balls of your feet, so your shoes should bend just underneath the balls of your feet.  If the shoes bend anywhere else, they are not providing adequate support for the foot, so can strain the Achilles tendon.  Some shoes, sandals, flip-flops, and moccasins bend everywhere, so do not provide adequate support.

Heel Cushioning

Cushioning is too soft if the heel sinks lower than the front of the foot. Too little cushioning overly strains and stretches the Achilles tendon.  The heel of most running shoes is slightly cushioned, which is fine.

Heel Height

  • Low Heel Height is Bad.  Too little heel height overly strains and stretches the Achilles tendon.  If the heel sinks lower than the forefoot, the heel height is too low.  Racing flats, heelless spikes, flip-flops, moccasins, and shoes with heel heights lower than 1/2″ – 5/8″ (12-15 mm) have too little heel heights.
  • High Heel Height is Bad.  The greater a shoe’s heel height, the less stretching the Achilles tendon does with each stride and the smaller the calf muscles’ range of motion.  Too short a range of motion promotes calf muscle shortening, disproportionate weakness in the parts of the calf muscle that are not stretched with each step, and possibly a general weakening of the calf muscle.  Frequent wearing of high heels reduces the length of the Achilles tendon, which can lead to later injury.   High heels are the worst; some boots are almost as bad.
  • Good Heel Heights.  The heel of most running shoes and most men’s dress shoes is slightly elevated, which is fine.
  • Why High Heels are Bad but Temporary Heel Lifts/Pads are Good.  On the one hand:  long term wearing of high heels or use of heel lifts/pads induces shortening of the gastrocnemius (calf) muscle, reduces its range of motion, and increases Achilles tendon stiffness.  On the other hand: short term temporary use of heel lifts/pads can help Achilles tendon injury recovery by temporarily reducing the range of motion to reduce strain on the Achilles tendon during the initial injury recovery process.  As progress is made with injury recovery, the temporary heel lifts/pads should be reduced and then eliminated to allow full range of motion for the calf muscle and avoid Achilles tendon stiffness.

Pronation

  • Pronation.  Pronation is the foot’s contact with the ground as you run.  Normal pronation is: the outside of the heel making initial contact, the foot rolling inward a bit (approximately 15%), complete contact with the ground, and then an even push off by the front of the foot.  Most people have normal pronation.  Gait analysis can be tricky, so if it is performed by non-professionals may result in a misdiagnosis of over or under pronation.  If you suspect that you have pronation problems, check with a doctor to be certain
  • Pronation Problems.  Of the people with pronation problem, most over pronate and only a few under pronate.  Typically, people with flat feet (fallen arches) are more likely of over pronate, while those with high arches are more likely to under pronate.
    • Over pronation is also known as excess pronation or hyper-mobile feet.  In over pronation the foot rolls inward more than a bit, and most of the push off is done by the big and second toe.
      • Over pronation can lead to Achilles tendon injuries, but the reverse can also be true: tight or short Achilles tendons can cause over pronation. If the pronation is caused by something other than tight or short Achilles tendons, then a motion control shoe will probably be helpful. If Achilles tendon tightness is causing the pronation, then motion control shoes are probably not appropriate.  Check with a physician to be certain.
      • Anti-pronation (also known as motion control) shoes prevent excessive pronation by being harder to twist than normal.  This decreases the amount of muscle activity around the ankle, subtalar joint (just below the ankle), and Achilles tendon.  The overall anti-pronation quality of a shoe can be tested by holding it with one hand at the widest point and one hand at the heel, and then twisting the shoe as though the ankle were leaning inward. The more difficult it is to twist, the more anti-pronation the shoe.
    • Under pronation is also known as supination.  In under pronation the foot rolls inward less than a bit.  Under pronation can be visible on your running shoes: the outer edges wear out sooner.   Shoes designed for supination appear to be rare.

Barefoot Running and Achlles Tendons

Barefoot Running has generated a lot of interest, but research suggests that it neither increases nor decreases the likelihood of an Achilles tendon injury.  For some people, running barefoot, or using barefoot-like shoes, is the correct footwear.

Achilles Tendon Braces, Casts, Etc.

A temporary brace may be required to immobilize the foot after a severe Achilles tendon injury, such as an Achilles tendon rupture. The braces used to steady the Achilles tendon, range from wrap devices that provide a little support to immobilization devices that prevent the Achilles tendon from flexing or pointing.  Some sports shoes, such as hockey skates and ski boots, have some of the immobilisation characteristics of braces, which may help athletes in those sports avoid, or recover faster from, Achilles tendon injury.  Consult a doctor prior to considering any brace or cast.

Achilles Tendon Orthotic Guidelines

Some people have such unique feet or biomechanics, that custom build individualized shoes (orthotics) are required.  Consult with a doctor to be certain.  Orthotics can be both very beneficial and very expensive.  Orthotics should be full length (rather than ending at the arch), and made of flexible (rather than hard material). Full length is important because 70% of the time that a foot is on the ground during a stride, the weight is on the forefoot. People with Achilles tendon concerns should discuss orthotic features relating to: cushioning, heel height, degree of arch support, and anti-pronation with their physician. Working with a doctor is important because orthotics often require expert readjustment before they are completely effective.

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