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Achilles Tendonitis: A Primer


The Achilles tendon runs along the lower, back part of your leg and connects the calf muscles (gastrocnemius and soleus) to the heel. It’s the strongest, largest, and most often injured tendon in the body. When it becomes inflamed, the condition is called Achilles tendinitis (also spelled tendonitis).

How Achilles Tendonitis Happens

Tendinitis is a classic overuse injury. The Achilles tendon is used every time you push off to take a step, so it’s not surprising that it can easily become irritated, inflamed, or even ruptured.

As your calf muscle contracts time after time, small microtears appear in the tendon. If the muscle or tendon is weak, tendinitis can develop. Even well trained athletes can develop tendinitis if they drastically change workout routines or playing surfaces, or wear shoes that don’t provide adequate support.

Other factors that can contribute to the problem include high arches, feet and ankles that roll inward excessively, and running on hard surfaces. Less commonly, trauma or infection can cause Achilles tendinitis.

“There is usually not one cause of Achilles tendinitis, and treating only the site of pain is an incomplete strategy,” says Steve Smith, PT, DPT, SCS, CSCS, Manager, Performance Physical Therapy Services at Athletes’ Performance in Gulf Breeze, Fla. “A comprehensive assessment of posture and movement patterns is needed to identify potential weak links that make you more susceptible to these types of injuries.”

In some instances, resting and changing your footwear will alleviate pain, but other factors like a lack of mobility or stability, or poor running mechanics are often underlying problems.

Achilles Tendonitis by the Numbers

1,000 +
Pounds of force the Achilles tendon is capable of withstanding.

6 to 18
Percentage of runners in which Achilles tendinitis occurs.

Who's at Risk for Achilles Tendonitis

Distance runners and people who play stop-and-go sports (tennis) or jumping activities (basketball), as well as dancers, most often fall victim to Achilles tendinitis.


  • Pain that develops gradually.
  • Heel pain, especially when running, climbing stairs, jumping, pointing toes down or walking on toes.
  • Increased pain with increased activity.
  • Pain after periods of inactivity.
  • Tenderness to touch (of the tendon).
  • Stiffness that decreases as you warm up.
  • Mild swelling or a bump on the tendon.
  • Creaking or cracking sensation.
  • Pain while walking or running uphill.

Initial Treatment

  • Rest. Don't try to play through the pain.
  • Apply ice in 20-minute intervals several times a day during the first 48-72 hours after the injury.
  • Aspirin, ibuprofen, and naproxen may relieve pain and reduce inflammation.
  • After 48-72 hours, moist heat to increase circulation and relieve discomfort and gentle, prolonged, static stretching of the calf.
  • Use heel inserts in your shoes to take pressure off of the Achilles tendon.
  • Seek medical help if pain persists for a week or more.

Comeback Strategy

Following your rehabilitation period, incorporate the activities that follow to progress back to your sport, suggests Smith. They'll help get your body ready for the dynamic nature of athletics again.

Movement Prep

  1. Wall Drill - Acceleration Static Hold
    Why it helps: Integrates stability of your shoulders, trunk, and hips and fine-tunes running posture.
  2. Knee Hug
    Why it helps: This exercise is a great way to build strength, stability and mobility, while working on running mechanics.
  3. Pillar Skips - In Place
    Why it helps: This exercise will improve your dynamic flexibility and elasticity to help make you springier out on the road.

Strength and Stability 

  1. Single Leg Squat
    Why it helps: This exercise will work your glutes, quads, and hamstrings.
  2. Romanian Deadlift - 2 arm/1leg
    Why it helps: This lift will help lengthen and strengthen your hamstrings, as well as your glutes and lower back. It will also challenge your balance and stability on a single leg like running.
  3. Forward Lunge
    Why it helps: Both forward and reverse lunges will challenge your body’s balance, stretch your hip flexors, as well as strengthen the opposite leg’s glutes.

How to Avoid Achilles Tendonitis

Be proactive instead of reactive. Use the movement prep exercises and prehab activities recommended by Smith before you train.


Incorporate some of these prehab activities into your warm-up routine. Do 1 to 3 sets of 8 to 12 repetitions daily.

  1. Sidelying Clamshells
    Why it helps: Improves the use of the deep six hip rotators essential for keeping your foot and ankle aligned.
  2. Glute Bridge
    Why it helps: Helps you extend your hips by using your glutes.
  3. Pillar Bridge - Front
    Why it helps: This movement builds strength and stability through your hips, torso, and shoulders.

Movement Prep

  1. Mini Band Lateral Straight Leg Walk
    Why it helps: Useful for muscles used to maintain powerful upright position on a single leg in running.
  2. Handwalk
    Why it helps: Improves trunk stability and dynamic hamstring/ calf stretching prior to training or running.

5 More Tips to Avoid Achilles Tendonitis

  1. Avoid sudden, dramatic changes in exercise duration, intensity, frequency, and location.
  2. Wear shoes that provide plenty of cushioning for the heel.
  3. Wear heel cups, arch supports, custom orthotics to distribute the forces placed on the lower leg evenly.
  4. Change running shoes every 300-500 miles.
  5. Don't increase exercise intensity, duration or frequency more than 10 percent a week.

 Jim Brown, Ph.D. has written 14 books on health, medicine, and sports. His articles have appeared in the Washington Post, New York Post, Sports Illustrated for Women and Better Homes & Gardens. He also writes for the Duke School of Medicine, UCLA School of Medicine, Cleveland Clinic and Steadman-Hawkins Research Foundation.

Tags: Injury Prevention, Heel Pain, Calves, Injury, Prehab, Tennis, Basketball, Rehabilitation, Running, Ankle


  1. Steve Smith, PT, DPT, SCS, CSCS, Manager, Performance Physical Therapy Services, Athletes’ Performance, Florida
  2. American Academy of Orthopaedic Surgeons
  3. National Institutes of Health (Medline Plus)
  4. The Mayo Clinic