Key Takeaway
Eccentric overload training using a flywheel device significantly reduced pain and improved calf muscle function in patients with chronic Achilles tendinopathy over a 12-week program.
Summary
This randomized controlled study by Silbernagel et al. (2001) evaluated the effects of eccentric overload training on patients with chronic Achilles tendon pain. The intervention group performed calf exercises on a flywheel device that provided eccentric overload, while the study also established the reliability of the clinical evaluation methods used to track outcomes including pain, strength, and functional performance. Patients in the eccentric overload group showed significant reductions in pain scores and meaningful improvements in calf muscle strength and endurance compared to baseline and controls. The flywheel device was particularly well-suited for this application because it delivers high eccentric loads through the full range of ankle dorsiflexion — the exact movement pattern that stresses the Achilles tendon. This early RCT was among the first to demonstrate that flywheel-based eccentric loading could be applied therapeutically to tendinopathy, laying groundwork for what has become a widely adopted approach in sports medicine and physiotherapy for managing chronic tendon conditions.