Does Resistance Training Protocol Change Micromorphology in Achilles Tendinopathy?

May 2, 2026 updated by: Stanislav Machač, Ph.D, University Hospital, Motol
This work is designed as a prospective cohort study, in which the effects of a protocol of 12-week resistance training loading the Achilles tendon in patients with Achilles tendinopathy (AT) will be monitored. It is estimated that at least 20 patients will participate. In addition, there will be a small control group of healthy participants which will not complete the same protocol, but will be monitored for natural changes in same objectives. Group of patients will be instructed to perform a training protocol.

Study Overview

Status

Withdrawn

Conditions

Intervention / Treatment

Detailed Description

The research within one participant will last a total of 26 weeks from the initial to the final examination and will include control measurements at 6 and 12 weeks from the beginning of therapy. Potential participants will be selected based on the recommendation of a specialist doctor and their suitability will be assessed according to the inclusion criteria. They will then be invited to an initial examination. This will include an objective examination by a physiotherapist, a subjective assessment by the patient and an ultrasonographic (USG) examination followed by a micromorphological analysis using special software. At the end of the initial examination, the participant will be informed about training protocol.

Study Type

Interventional

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Czechia
      • Prague, Czechia
        • University Hospital Motol and 2nd Faculty of Medicine, Charles University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • the patient shows symptoms of Achilles tendinopathy (pain, swelling and dysfunction in the area of Achilles tendon), which at least partially limit his quality of life during normal or sporting activities,
  • the patient is in the age group of 18-60 years,
  • the patient has difficulties in only one lower limb; the second, asymptomatic limb will be considered the reference,
  • the patient is not aware of any mechanical damage to the tendon in symptomatic limb in the past (e.g. partial or complete rupture as a result of an injury),
  • the patient has not undergone any treatment aimed at AS in the last 3 months (surgery, corticoid application, plasma therapy, shock waves, physiotherapy, etc.), objective US examination of AS shows structural changes (expansion, neovascularization, focal hypoechoic areas, etc.).

Exclusion Criteria:

  • patient has been diagnosed with a rheumatic disease or a disease of the central nervous system
  • patient is aware of mechanical damage to the Achilles tendon as a result of an injury in the past.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Non-Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Resistance training protocol
Participants in this group will complete a 12-week ankle dorsiflexion resistance training protocol according to Silbernagel. It is a series of heel rise exercises with a gradual progression of load according to defined criteria, which the patient practices every day.
Other: Achilles Tendon Loading Exercise Protocol According to Silbernagel
It is a 12-week Silbernagel ankle dorsiflexion resistance training protocol. It is a series of exercises with a gradual progression of load according to defined criteria, which the patient practices every day.
No Intervention: Participants with healthy tendons

Participants in this group are considered healthy based on subjective judgment followed by clinical and ultrasound examination of the Achilles tendon.

In this group, no specific treatment will be performed, only Achilles tendon will be monitored through time.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Peak Spatial Frequency Radius at the site of Pathology
Time Frame: Change of initial values at 26 weeks follow up after beginning of the therapy.
Measured by spatial frequency analysis software from ultrasound picture in mm-1. In a linear view with specific settings of ultrasound machine, the site of the largest pathology is selected, then the image is saved and uploaded to the software that evaluates the PSFR parameter.
Change of initial values at 26 weeks follow up after beginning of the therapy.
Change in Tendon Diameter at the Place of Maximum Tendon Width
Time Frame: Change of initial values at 26 weeks follow up after beginning of the therapy.
Measured by tools in ultrasound machine in mm2. In linear view is selected maximal width place, then the tendon diameter is measured using device tools.
Change of initial values at 26 weeks follow up after beginning of the therapy.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in VISA-A Questionnaire Score
Time Frame: Change of initial values at 39 weeks follow up after beginning of the therapy.
The VISA-A questionnaire is standardized questionnaire for patients with Achilles tendinopathy. The results are recorded in points (0-100 points). The higher score indicates patients better condition.
Change of initial values at 39 weeks follow up after beginning of the therapy.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University Hospital, Motol

Investigators

  • Study Chair: Stanislav Machac, PhD, University Hospital Motol and 2nd Faculty of Medicine, Charles University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 1, 2023

Primary Completion (Estimated)

May 1, 2024

Study Completion (Estimated)

May 1, 2024

Study Registration Dates

First Submitted

August 19, 2023

First Submitted That Met QC Criteria

August 19, 2023

First Posted (Actual)

August 24, 2023

Study Record Updates

Last Update Posted (Actual)

May 7, 2026

Last Update Submitted That Met QC Criteria

May 2, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • EK-402 /22b

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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