Key Exercise Parameters in Achilles Tendinopathy Rehabilitation: Expert Consensus

Why It Matters

Achilles tendinopathy (AT)—persistent tendon pain and loss of function related to mechanical loading—affects 6% of the general population, up to 24% of elite athletes, and more than 50% of long-distance runners. Despite established protocols, recurrence rates remain high (23–43%), and long-term symptoms persist in as many as 60% of cases.

Exercise remains the cornerstone of management, but uncertainty exists around the optimal exercise parameters. A study gathered 17 international expert consensus to clarify which aspects of heel raise exercise (a standard AT intervention) matter most.

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Key Findings for Therapists

1. Contraction Intensity – The Most Critical Factor

• High contraction intensity drives tendon adaptation.
• Tendon strain of 4.5–6.5% is required to stimulate remodeling.
• High loads (70–90% MVC) appear most effective, though inter-individual variability means even lower intensities may sometimes be sufficient.
• Clinically: aim for heavy, controlled loading, but balance against risk of overloading.

2. Loading Volume – Sets, Reps & Time Under Tension (TUT)

• Consensus: important for both midportion & insertional AT.
• Sufficient stimulus is needed, but excessive or insufficient volume may hinder adaptation.
• Experts favored slow, prolonged contractions over fast, short ones.
• Total TUT was especially emphasized for midportion AT.
• Clinically: progress volume gradually, and tailor sets/reps to both tendon capacity and psychological tolerance.

3. Type of Contraction

• No clear superiority of eccentric vs concentric vs isometric—all can load the tendon effectively.
• Plyometrics play a distinct role, best reserved for later stages to prepare for high functional demands.
• Clinically: use a variety of contraction types, individualized to deficits identified in assessment.

4. Range of Dorsiflexion

• Insertional AT: avoid deep dorsiflexion in early stages, as it increases compressive load against the calcaneus.
• Midportion AT: full range recommended as soon as tolerated, to reflect functional demands.
• Clinically: protect insertional tendons early, then progressively restore full ROM.

5. Pain as a Guide

• Pain did not reach consensus as a primary exercise parameter.
• Instead, pain is best used as a regulatory tool—helping clinicians titrate load intensity and volume.
• Education around “acceptable pain” is essential to reduce kinesiophobia and improve adherence.

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Practical Implications for Therapists

• Prioritise contraction intensity: ensure sufficient tendon strain while avoiding overload.
• Volume matters: prescribe adequate sets/reps and TUT, using slower tempos early on.
• Match contraction type to stage: eccentric/isometric early, add plyometrics later.
• Respect insertional mechanics: avoid excessive dorsiflexion early, progress gradually.
• Pain is feedback, not failure: use it to regulate, not avoid, tendon loading.

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Conclusion

This expert consensus study provides clinicians with a clearer framework for exercise prescription in AT:

• Midportion AT → focus on contraction intensity, TUT, sets/reps, and contraction type.
• Insertional AT → contraction intensity + careful management of dorsiflexion range.