Exercise Therapy for Tendinopathy: Achilles Tendon, Patellar Tendon, Rotator Cuff

Introduction: Rest Is Not the Answer

If you’ve ever been troubled by tendon problems, you’ve probably heard these pieces of advice: “Rest,” “Ice it,” “Take anti-inflammatories,” “Don’t move it at all.” You may have also discovered that—resting for a few days feels a bit better, but the pain comes right back once you resume training.

This isn’t a problem with your recovery; rather, “complete rest” as a treatment strategy is itself wrong.

Nearly 20 years of tendon research has completely transformed our understanding and treatment of tendinopathy. The core shift in thinking is this: tendons don’t need “protection”—they need appropriate mechanical loading.

Understanding Tendinopathy: It’s Not Simply “Inflammation”

From Tendinitis to Tendinopathy

In the past, all tendon problems were called “tendinitis,” implying the primary issue was inflammation. However, histological studies show that inflammatory cells are virtually absent in chronic tendon problems.

The correct term is “tendinopathy,” whose pathological features include:

• Disorganized collagen arrangement (loss of normal parallel structure)
• Altered matrix composition (increased proteoglycans)
• Neovascularization
• Nerve fiber proliferation (a potential source of pain)
• But not inflammation

The Cook-Purdam Tendinopathy Continuum Model

Australian physiotherapy researcher Professor Jill Cook proposed the influential “Continuum Model,” which divides tendinopathy into three stages:

Stage 1: Reactive Tendinopathy

• Short-term response following an acute increase in load
• Tendon swelling, pain
• Reversible—if load is appropriately adjusted, full recovery is possible
• Commonly seen in athletes who suddenly increase training volume

Stage 2: Tendon Dysrepair

• If the reactive stage is not properly managed, structural changes begin
• Collagen becomes disorganized, matrix changes occur
• Still partially reversible

Stage 3: Degenerative Tendinopathy

• Severe collagen disorganization with fatty infiltration
• Structural changes are irreversible
• But function can still improve through strengthening the surrounding healthy tissue
• Commonly seen in chronic problems that have been ignored long-term

Key concept: Even a degenerative tendon does not mean function cannot be restored. Tendon pain and function are not entirely determined by structural changes—a tendon that looks terrible on MRI may be completely pain-free, and vice versa.

Exercise Therapy for Three Common Tendinopathies

1. Achilles Tendinopathy

At-risk populations: Runners (prevalence 5-12%), middle-aged athletes

Classification:

• Midportion tendinopathy: Located 2-6 cm from the calcaneal insertion; the most common
• Insertional tendinopathy: At the calcaneal attachment; often associated with bursitis

Eccentric Training Protocol (Alfredson Protocol):

This is one of the most well-researched exercise protocols for tendon conditions:

1. Stand on the edge of a step, on the balls of your feet
2. Rise up onto your toes using your healthy leg
3. Remove the healthy leg, and lower slowly using only the affected leg (3-5 seconds) until the heel drops below the step surface
4. Do not push back up with the affected leg—rise again using the healthy leg
5. 3 sets × 15 reps, twice daily
6. Do 3 sets with the knee straight (targeting the gastrocnemius) and 3 sets with the knee slightly bent (targeting the soleus)
7. Moderate pain is allowed (VAS ≤5/10)
8. When you can complete the exercise pain-free, add resistance (books in a backpack or a weighted vest)

Progression timeline: It typically takes 12 weeks of consistent training to see significant improvement. Patience is key.

Note for insertional tendinopathy: The original Alfredson Protocol is not suitable for insertional tendinopathy (because lowering the heel below the step compresses the insertion site). For insertional tendinopathy, the exercise should be performed on a flat surface, without lowering the heel below ground level.

2. Patellar Tendinopathy (Jumper’s Knee)

At-risk populations: Cyclists (when the saddle is too low), runners, jumping athletes

Pain characteristics: Pain below the patella, especially during squats, stair climbing, or high-power pedaling on a bike

Isometric Loading Protocol:

Research by Rio et al. (2015) showed that isometric contractions can produce immediate pain relief (possibly through cortical-level pain inhibition mechanisms):

• Spanish Squat: Secure the lower legs with a strap, knees flexed at approximately 70-90°
• Hold the isometric contraction for 45 seconds
• 4-5 sets, 2-3 times daily
• Can be used as a warm-up before training to temporarily reduce pain

Progressive Loading Protocol:

1. Weeks 1-2: Isometric training (as above)
2. Weeks 3-4: Double-leg squats (controlled tempo, 3 seconds down, 3 seconds up)
3. Weeks 5-8: Single-leg squats, split squats
4. Weeks 9-12: Add speed and explosiveness (box jumps, jump squats)
5. From week 13: Return to sport-specific training

3. Rotator Cuff Tendinopathy

At-risk populations: Cyclists (prolonged weight-bearing through the hands), swimmers, triathletes

Common presentation: Pain in the front or side of the shoulder, especially with overhead arm elevation or reaching backward

Exercise Therapy Principles:

1. Isometric external rotation: Arm close to the body, elbow bent at 90°, perform isometric external rotation against a resistance band, hold for 30-45 seconds × 4 sets
2. Scapular stabilization training: Low rows, Y-T-W exercises
3. Progressive external/internal rotation resistance training: Resistance band, 3 × 12-15
4. Eccentric rotator cuff training: Using a dumbbell, slow eccentric lateral raises
5. Do not completely avoid overhead movements—instead, progress gradually from low loads

General Treatment Principles

Load Management Is the Core

Professor Cook’s famous quote: “Tendons like to be loaded, but they don’t like to be abused.”

• Do not rest completely (this leads to tendon deconditioning, making it more vulnerable when resuming training)
• Do not push through pain and ignore it (this accelerates degenerative changes)
• Find the “sweet spot”: allow mild to moderate discomfort (VAS ≤ 3-4/10), but pain should not continue to worsen for more than 24 hours after exercise

The “24-Hour Rule”

Assessing the tendon’s pain response after training:

• Pain during exercise ≤ 3-4/10 → Acceptable
• Pain returns to baseline within 24 hours after exercise → Load is appropriate
• Pain remains above baseline beyond 24 hours after exercise → Load is too high and needs adjustment

The Role of Anti-Inflammatory Drugs (NSAIDs)

Acute reactive stage: Short-term use (5-7 days) may be helpful

Chronic tendinopathy: Long-term use is not recommended

• May interfere with collagen synthesis
• Pain relief may lead athletes to overload the tendon
• Long-term use has gastrointestinal and renal side effects

Injection Therapy

Corticosteroid injections:

• Good short-term pain relief (2-4 weeks)
• But medium- to long-term results are inferior to exercise therapy
• May weaken tendon structure and increase the risk of rupture
• Generally not recommended for the Achilles tendon

PRP (Platelet-Rich Plasma) injections:

• Theoretically provide growth factors to promote healing
• Current evidence is inconsistent, and the effect is uncertain
• Relatively expensive (out-of-pocket cost in Taiwan approximately NT$10,000-20,000 per session)
• Can be considered as one option after failed conservative treatment

Special Considerations for Cyclists

• Saddle Height: Too low increases patellar tendon load; too high increases Achilles tendon load
• Crank Length: Shorter cranks reduce extreme angles at the knee and ankle joints
• Cadence: Low cadence with high torque places greater load on tendons
• Cleat Position: Cleats positioned too far forward increase Achilles tendon load

Medical Resources in Taiwan

• Sports Medicine Departments: Medical centers such as National Taiwan University Hospital, Linkou Chang Gung Memorial Hospital, and Kaohsiung Medical University Hospital
• Rehabilitation Departments: Provide physical therapy prescriptions and ultrasound/MRI examinations
• Physical Therapy Clinics: Look for therapists with expertise in sports injuries and familiarity with load management concepts
• Shockwave Therapy: Already widely available in Taiwan, partially covered by National Health Insurance, and an effective option for mid-stage treatment

Conclusion

Treating tendinopathy requires patience, discipline, and the right mindset. Forget the old thinking of “rest and let it heal,” and embrace the new paradigm of “progressive loading and long-term training.”

Twelve weeks of systematic exercise therapy outperforms any injection, medication, or passive treatment. Your tendons are tougher than you think, but they need the right stimulus to prove it.

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References

• Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br J Sports Med. 2009;43(6):409-416.
• Alfredson H, et al. Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis. Am J Sports Med. 1998;26(3):360-366.
• Rio E, et al. Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. Br J Sports Med. 2015;49(19):1277-1283.
• Malliaras P, et al. Patellar tendinopathy: clinical diagnosis, load management, and advice for challenging case presentations. J Orthop Sports Phys Ther. 2015;45(11):887-898.

Related Reading

• Tendinitis vs. Tendinopathy: An Overuse Injury Guide for Endurance Athletes
• Achilles Tendinopathy: Why Eccentric Training Is the Gold Standard for Rehabilitation
• Conservative Treatment for Achilles Tendinitis and Return-to-Training Criteria
• Tendon Pathology in Achilles Tendinopathy: Research on Neovascularization and Collagen Disorganization