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Updated: May 17, 2026
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A Passive Ankle Dorsiflexion Testing System for an In Vivo Model of Overuse-induced Tendinopathy
Published on: March 1, 2024
Achilles tendinopathy modulates force frequency characteristics of eccentric exercise
Nicole L Grigg1, Scott C Wearing, John M O'Toole
1Institute of Health and Biomedical Innovation, Queensland University of Technology, Kelvin Grove, Queensland, Australia. n.grigg@griffith.edu.au
Medicine and Science in Sports and Exercise
|October 18, 2012
Summary
Achilles tendinopathy alters vibration frequencies during eccentric exercise, showing lower frequencies in affected limbs compared to healthy controls. This difference may explain varied responses to eccentric rehabilitation in injured tendons.
Area of Science:
- Biomechanics
- Musculoskeletal Research
- Rehabilitation Science
Background:
- Eccentric exercise shows higher power in the 8-12 Hz bandwidth than concentric exercise.
- This 8-12 Hz vibration range is hypothesized to aid tendon repair.
- Previous studies focused only on healthy Achilles tendons.
Purpose of the Study:
- To compare force frequency characteristics of eccentric and concentric exercises.
- To investigate these characteristics in individuals with and without Achilles tendinopathy.
Main Methods:
- Eleven males with Achilles tendinopathy and nine healthy males participated.
- Kinematics and ground reaction forces (GRF) were recorded during eccentric and concentric ankle exercises.
- Ankle joint kinematics and GRF frequency power spectrum were analyzed.
Main Results:
- Eccentric exercise exhibited significantly more spectral power between 4.5-11.5 Hz than concentric exercise.
- No significant limb differences were found for concentric exercise.
- Eccentric exercise in the symptomatic limb showed a spectral peak shift to 9 Hz, unlike the 10 Hz peak in controls.
Conclusions:
- Achilles tendinopathy is associated with lower frequency vibrations during eccentric rehabilitation.
- This may be linked to altered neuromuscular activation and tendon stiffness in tendinopathy.
- Provides a rationale for differing biochemical responses to eccentric exercise in healthy vs. injured tendons.
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