Medical Disclaimer: This information is for educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.
Monitor Symptoms
πŸ’ͺMuscles & Joints
Medically Reviewed

Achilles Tendonitis (Achilles Tendinopathy)

Inflammation and degeneration of the Achilles tendon β€” the largest and strongest tendon in the body, connecting the calf muscles to the heel bone. Causes posterior heel and lower calf pain, especially with activity.

Last updated:

Statistics & Prevalence

**Achilles tendonitis** (more accurately termed **Achilles tendinopathy**) is the most common overuse injury of the Achilles tendon β€” the thick band connecting the calf muscles (gastrocnemius and soleus) to the calcaneus (heel bone). - Lifetime prevalence: **6-17%** in runners; **2%** in the general population - The Achilles tendon is the **strongest** tendon in the body β€” withstands forces of **6-8x body weight** during running - **Two types**: insertional (at the heel bone, 20-25%) and mid-portion (2-6cm above the heel, 75-80%) - Men affected **6x more** than women - Peak incidence ages **30-50** β€” the "weekend warrior" demographic - Running accounts for **50-65%** of all cases β€” particularly sudden training increases - **75-80%** respond to conservative treatment (eccentric exercises are the gold standard) - Eccentric calf exercises (Alfredson protocol) show **60-90%** success rate in clinical trials - Risk of **Achilles rupture**: 1-2% of tendinopathy cases; risk increases with fluoroquinolone antibiotics and corticosteroid injections

Visual Guide: Achilles Tendonitis (Achilles Tendinopathy)

Runner performing eccentric heel drop exercise for Achilles tendonitis rehabilitation

The Alfredson eccentric heel drop protocol is the gold standard treatment for Achilles tendinopathy β€” 3 sets of 15 slow heel drops, twice daily for 12 weeks. Success rates of 60-90% in clinical trials.

Note: Images are for educational purposes only and may not represent every individual's experience with achilles tendonitis (achilles tendinopathy).

What is Achilles Tendonitis (Achilles Tendinopathy)?

**Achilles tendinopathy** is a condition characterized by pain, swelling, and impaired function of the Achilles tendon due to overuse, degeneration, or a combination of both. Modern terminology favors "tendinopathy" over "tendonitis" because the condition is more degenerative than inflammatory. **Two distinct types:** **1. Mid-Portion Achilles Tendinopathy (75-80% of cases):** - Affects the tendon **2-6 cm above its insertion** on the heel bone - This is the "watershed zone" β€” an area of relatively poor blood supply, making it vulnerable to degeneration - Characterized by a painful, thickened, nodular tendon - Most common in runners and active individuals **2. Insertional Achilles Tendinopathy (20-25% of cases):** - Affects the tendon **at its attachment to the heel bone** (calcaneus) - Often associated with a Haglund's deformity (bony bump on the back of the heel) and retrocalcaneal bursitis - Common in less active individuals and those who wear rigid-heeled shoes - May have calcification within the tendon at the insertion The Achilles tendon withstands enormous forces β€” **6-8x body weight during running** and **2-4x during walking**. When the tendon's repair capacity is exceeded by the mechanical demands placed on it, tendinopathy develops.

Common Age

Active adults 30-50; runners peak incidence; men 6x more affected than women

Prevalence

6-17% lifetime prevalence in runners; 2% in the general population; accounts for 6-17% of all running injuries; the most common overuse injury of the lower leg

Duration

Acute tendonitis: 2-6 weeks with rest and eccentric exercises. Chronic tendinopathy: 3-6 months of structured rehabilitation. 75-80% resolve conservatively; 20-25% become chronic

Why Achilles Tendonitis (Achilles Tendinopathy) Happens

## Root Causes **Training Errors (60-70% of cases):** - Sudden increase in running mileage or intensity (>10% weekly increase) - Adding hill running or speed work too quickly - Returning to high-impact sport after a layoff without gradual progression - Running on hard surfaces (concrete) or cambered roads **Biomechanical Factors:** - Tight calf muscles (gastrocnemius/soleus) β€” the #1 modifiable risk factor - Overpronation (flat feet) β€” increases Achilles tendon whipping motion - Leg length discrepancy β€” overloads the shorter leg's Achilles - Weak calf muscles relative to activity demands **Intrinsic Risk Factors:** - Age 30-50 β€” tendon degenerative capacity increases with age - Male sex (6x higher risk than women) - Previous Achilles tendon injury β€” recurrence rate 27-50% - Obesity β€” increases tendon loading - Diabetes and metabolic syndrome β€” impaired tendon healing - Fluoroquinolone antibiotics (ciprofloxacin, levofloxacin) β€” increase tendon rupture risk 2-4x - Systemic corticosteroid use **Footwear:** - Shoes with inadequate heel support or cushioning - Sudden change from high-heeled to flat shoes (increased Achilles stretch) - Worn-out running shoes (replace every 400-500 miles)

Common Symptoms

  • Pain at the back of the heel and lower calf β€” worse with activity
  • Morning stiffness in the tendon β€” first few steps are stiff and painful
  • Thickened, nodular tendon that is tender to squeeze (mid-portion type)
  • Pain at the start of exercise that may decrease then return afterward ("warm-up" phenomenon)
  • Difficulty performing single-leg calf raises
  • Swelling along the tendon β€” visible compared to the unaffected side
  • Crepitus β€” creaking sensation when moving the ankle
  • Pain walking uphill or climbing stairs
  • Insertional pain at the back of the heel bone (insertional type)

Possible Causes

  • Sudden increase in running volume or intensity β€” the most common trigger
  • Tight calf muscles (gastrocnemius/soleus) β€” the #1 modifiable risk factor
  • Age-related tendon degeneration (30-50 year olds most affected)
  • Overpronation (flat feet) increasing Achilles tendon strain
  • Running on hard surfaces or cambered roads
  • Worn-out or inadequate running shoes
  • Previous Achilles injury β€” recurrence rate 27-50%
  • Fluoroquinolone antibiotics β€” increase tendon damage risk 2-4x

Note: These are potential causes. A healthcare provider can help determine the specific cause in your case.

Quick Self-Care Tips

  • 1Start the Alfredson eccentric heel drop protocol β€” the gold standard treatment (3x15 reps, 2x daily, 12 weeks)
  • 2Reduce running volume by at least 50% until pain improves β€” don't stop completely
  • 3Use heel lifts (1-1.5 cm) in both shoes to reduce tendon strain
  • 4Stretch your calves daily β€” 30-second holds, straight knee AND bent knee, 3x daily
  • 5Ice the tendon after activity for 15-20 minutes
  • 6Replace running shoes every 400-500 miles β€” worn shoes increase Achilles stress
  • 7Never inject corticosteroids into the Achilles tendon β€” increases rupture risk
  • 8Cross-train with cycling or swimming to maintain fitness while the tendon heals

Disclaimer: These are general wellness suggestions, not medical treatment recommendations. They may help manage symptoms but should not replace professional medical care.

Evidence-Based Treatment

## Conservative Treatment (First-Line β€” 75-80% Success) **1. Eccentric Exercise Program (Gold Standard):** The **Alfredson protocol** is the most evidence-based treatment: - Stand on the edge of a step on the balls of your feet - Rise up on both feet, then SLOWLY lower on the AFFECTED leg only (heel drops below step level) - 3 sets of 15 repetitions, twice daily (90 reps/day) - Do with knee straight AND knee slightly bent (targets both gastrocnemius and soleus) - Continue for **12 weeks** even if pain initially increases β€” this is expected - Success rate: **60-90%** in clinical trials **2. Load Management:** - Reduce running volume by 50% or more until pain improves - Replace high-impact with low-impact training (cycling, swimming, elliptical) - Pain monitoring: activity is acceptable if pain stays below 5/10 and settles within 24 hours - Gradual return to sport: 10% weekly volume increase once pain-free with eccentric exercises **3. Calf Stretching and Flexibility:** - Wall stretch (straight knee for gastrocnemius, bent knee for soleus) - Hold 30 seconds, 3 reps, 3x daily - Avoid aggressive stretching in the acute phase β€” can irritate the tendon **4. Additional Measures:** - Heel lifts (1-1.5 cm) in both shoes β€” reduces tendon strain by 15-20% - Ice after activity β€” 15-20 minutes to reduce post-exercise swelling - NSAIDs for short-term pain relief during acute flares (avoid long-term β€” may impair healing) - Shockwave therapy (ESWT) β€” 60-80% effective for chronic cases (>3 months) **5. Avoid:** - Corticosteroid injection INTO the Achilles tendon β€” increases rupture risk 3-5x - Complete rest β€” leads to tendon deconditioning; controlled loading is better than rest - Fluoroquinolone antibiotics if possible β€” discuss alternatives with your doctor ## Surgical Treatment (20-25% of Chronic Cases) Indicated after 6+ months of failed conservative treatment: - **Debridement**: Removal of degenerative tendon tissue β€” 75-85% good outcomes - **Haglund's resection**: For insertional tendinopathy with bony prominence - **Tendon repair with augmentation**: For tendons with >50% degenerative involvement - Recovery: 3-6 months; full return to sport 6-12 months post-surgery

Risk Factors

  • Running β€” especially sudden training increases (>10% weekly)
  • Age 30-50 β€” tendon degeneration increases
  • Male sex β€” 6x higher risk than women
  • Previous Achilles injury β€” 27-50% recurrence rate
  • Tight calf muscles β€” the most important modifiable risk factor
  • Flat feet (overpronation) β€” increases tendon whipping motion
  • Fluoroquinolone antibiotics β€” increase tendon rupture risk 2-4x
  • Obesity and metabolic syndrome β€” impaired tendon healing
  • Systemic corticosteroid use

Prevention

  • Follow the 10% rule β€” never increase weekly running volume by more than 10%
  • Stretch calves daily β€” both straight-knee and bent-knee stretches
  • Eccentric calf raises as maintenance β€” even when pain-free, 3x15 twice weekly
  • Replace running shoes every 400-500 miles
  • Warm up properly before running β€” include dynamic calf stretches
  • Avoid running on hard surfaces exclusively β€” vary terrain
  • Strengthen calf muscles with progressive loading
  • If prescribed fluoroquinolones, discuss alternatives or reduce physical activity during treatment

When to See a Doctor

Consult a healthcare provider if you experience any of the following:

  • Achilles pain that persists beyond 2 weeks despite rest and home treatment
  • A sudden sharp "pop" in the back of the ankle β€” may indicate partial or complete rupture
  • Inability to push off or rise on toes β€” suggests significant tendon damage
  • Visible gap or depression in the tendon β€” suggests rupture
  • Pain that is present even at rest and disrupts sleep
  • Swelling and tenderness that is worsening despite activity modification
  • Taking fluoroquinolone antibiotics and developing Achilles pain β€” contact doctor immediately

Talk to a Healthcare Provider

If your symptoms are persistent, severe, or concerning, please consult with a qualified healthcare professional for proper evaluation and personalized advice.

Frequently Asked Questions about Achilles Tendonitis (Achilles Tendinopathy)

Click on a question to see the answer.

Yes β€” but with modifications. Complete rest is actually counterproductive (leads to tendon deconditioning). The key is load management: reduce volume by 50%+, avoid hill running and speed work, and monitor pain. Running is acceptable if pain stays below 5/10 during exercise and settles within 24 hours. If pain is above this threshold, reduce further or temporarily switch to cycling/swimming.

Eccentric exercises (slow lowering under load) stimulate tendon remodeling β€” encouraging the production of healthy aligned collagen fibers while breaking down disorganized degenerative tissue. The Alfredson protocol (heel drops off a step) is the gold standard with 60-90% success rates. Pain during the exercises is actually expected and acceptable β€” the tendon needs controlled loading to heal. Results typically appear after 6-8 weeks of consistent daily exercise.

Yes β€” degenerative tendons are at higher risk of rupture, especially with sudden explosive movements (jumping, sprinting). The rupture risk is about 1-2% of tendinopathy cases. Risk factors include: age >40, fluoroquinolone antibiotics (2-4x risk), corticosteroid injection into the tendon (3-5x risk), and ignoring chronic tendon pain. The classic sign of rupture is a sudden "pop" with immediate inability to push off or rise on toes β€” this requires emergency medical attention.

More Muscles & Joints Conditions

References & Sources

This information is based on peer-reviewed research and official health resources:

  • 1

    Achilles Tendinopathy: Current Concepts

    British Journal of Sports Medicine

    View Source
  • 2

    Management of Achilles Tendon Disorders

    American Academy of Orthopaedic Surgeons

    View Source

Was this information helpful?

35 people found this helpful

Your feedback is anonymous and helps us improve our content.

Medical Disclaimer

The information on this page is for educational purposes only and is not intended as medical advice. It should not be used for self-diagnosis or self-treatment. Always seek the guidance of a qualified healthcare professional with any questions you have regarding a medical condition. If you are experiencing a medical emergency, call your local emergency services immediately.

Explore QuickSymptom

Last Updated:

Reviewed by QuickSymptom Health Team

This content is for educational purposes only.

Not a substitute for professional medical advice.