Eccentric loading for tendon rehabilitation

Controlled eccentric load is the primary evidence-based stimulus for repairing tendinopathy.

Why it works

Tendons are mechanosensitive: controlled tensile load stimulates tenocytes to produce collagen and remodel disorganized tissue. Eccentric loading applies high, sustained tension through the tendon at longer lengths, which appears to be a particularly potent remodeling signal. The classic Alfredson heel-drop protocol for Achilles tendinopathy operationalizes exactly this principle and remains among the best-supported non-surgical treatments.

How to do it

1. Get a diagnosis from a physiotherapist before loading — not all tendon pain is the same.
2. For Achilles: stand on a step, raise both heels, then lower on the affected side only over 3 seconds.
3. Perform 3 sets of 15 repetitions, twice daily — the Alfredson protocol volume.
4. Expect some pain during loading (up to 5/10); sharp or worsening pain should stop the session.

Evidence

Eccentric tendon loading protocols have strong clinical and trial support for Achilles and patellar tendinopathy, with many patients achieving durable symptom resolution without surgery. Alfredson's original 1998 trial of the heavy-load heel-drop protocol saw chronic Achilles patients return to pre-injury activity, establishing the reference protocol still used today. (rct)

Evidence is strongest for Achilles and patellar tendons. Results vary; some patients do not respond and require additional interventions. Physiotherapist supervision is strongly recommended.

Sources

• Alfredson et al. (1998), "Heavy-load eccentric calf muscle training for the treatment of chronic Achilles tendinosis," American Journal of Sports Medicine
• Alfredson H, Pietilä T, Jonsson P, Lorentzon R (1998). "Heavy-Load Eccentric Calf Muscle Training for the Treatment of Chronic Achilles Tendinosis." American Journal of Sports Medicine, 26(3), 360-366.

Common mistake

Stopping when it first hurts. Controlled pain during eccentric tendon loading is expected and — within limits — is part of the therapeutic process. Stopping too early prevents the remodeling stimulus.