Cross-cultural Adaptation of the TENDINopathy Severity Assessment-Achilles (TENDINS-A) for the Spanish Population and Evaluation of Its Reliability and Validity in Accordance With COSMIN Recommendations
Conditions: Achilles Tendinopathy
Sponsor: Cardenal Herrera University

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
GENERAL STUDY INFORMATION AND INFORMED CONSENT 
 
UNIVERSITY CEU CARDENAL HERRERA  
 
Principal investigator: Dr. José Miguel Soria López 
 
TITLE: Cross-cultural adaptation of the TENDINopathy Severity Assessment–
Achilles. (TENDINS-A) for the Spanish population and evaluation of its reliability 
and validity in accordance with COSMIN recommendations. 
 
Research and Ethics Committee of CEU Cardenal Herrera University Number: CEEI 
24/558 
NCT ID: xxxxxxxxxxx   
DATE: Nov 28, 2025 
 
 
 

 
 
GENERAL STUDY INFORMATION 
 
TITLE: Cross-cultural adaptation of the TENDINopathy Severity Assessment–
Achilles. (TENDINS-A) for the Spanish population and evaluation of its reliability 
and validity in accordance with COSMIN recommendations: A Methodological / 
Psychometric validation study 
 
Mr. Dr. José Miguel Soria López, Biologist, principal investigator and researcher reports 
that: 
This project aims to carry out a Spanish cross-cultural adaptation of the TENDINS-A 
questionnaire, a patient-reported outcome measure (PROM) originally developed in 
English. 
To achieve this, an initial translation process will be performed following Beaton’s 
recommendations, resulting in a first translated version to be used for the validation studies 
of the questionnaire in Spanish. 
The study will be conducted in collaboration with various sports organizations and 
physiotherapy clinics. Individuals diagnosed with Achilles tendinopathy who consent to 
participate will be asked to complete three questionnaires at baseline (VISA-A, FAOS, and 
TENDINS-A) and, 48 hours later, the TENDINS-A retest. 
The data collected across groups and time points will allow the determination of whether 
the translated questionnaire demonstrates reliability, validity, responsiveness, and feasibility 
comparable to those of the original version. 
The general data of the subject will be collected (name, age, sex, physical variables and 
clinical history). The article must be sent with comfortable clothes The day that sea cited by 
the researcher, previous notice. Personal data is recognized in this study.  
 
The personal data are confidential, apply to the protection of personal data (Organic Law 
15/1999, December 13) and any other thing that may be applicable. 
 
This study was approved by the Research and Ethics Committee of CEU Cardenal Herrera 
University (CEEI24/558) 
 
 
 
 

 
INFORMED CONSENT 
  
Mr/Mrs................................................................................................... with Number 
identification ....................................... .. freely and voluntarily, I DECLARE: 
 
That I have read the information contained in this document about the general information 
of the study. 
 
I have been informed that all tests are simple to perform and do not produce harmful effects 
on health. They will be carried out in appropriate facilities and will be carried out by 
qualified and specialized personnel. 
 
I have also been informed that, the data collected in this study will be treated confidentially, 
applying the current legislation on protection of personal data (Organic Law 15/1999, of 
December 13) and any other applicable. 
 
Therefore, I give my consent and I authorize Mr. José Miguel Soria López, to carry out the 
detailed study in this document with the help of the necessary personnel with the 
appropriate qualification and specialization. 
 
In Elche, to ...... of .......................................... of 202 
 
Firm 

 
 
 
 
 
 
 
 
 
 
 
 
 
STUDY PROTOCOL PLAN AND STADISTICAL ANALYSIS PLAN (SAP)  
 
UNIVERSITY CEU CARDENAL HERRERA  
 
Principal investigator: Dr. José Miguel Soria López 
 
TITLE: Cross-cultural adaptation of the TENDINopathy Severity Assessment–
Achilles. (TENDINS-A) for the Spanish population and evaluation of its reliability 
and validity in accordance with COSMIN recommendations. 
 
 
Research and Ethics Committee of CEU Cardenal Herrera University Number: CEEI 
24/558 
 
NCT ID: XXXXXXXXXXX 
DATE: Nov 28, 2025 
 
 
 
 

 
STUDY PROTOCOL PLAN 
 
Objectives: 
The objectives of our study have been the following: 
 
General: 
 
• To perform the cross-cultural adaptation of the TENDINS-A questionnaire into the 
Spanish language. 
• To validate the content of the Spanish version of the TENDINS-A questionnaire in 
relation to the original version. 
• To assess its psychometric properties in the target Spanish population. 
 
 
 
Volunteers who want to participate in the study will read the general information of the 
study and sign the informed consent to participate in the study. 
 
Once the informed consent has been read and delivered, the evaluator will check that 
they meet the inclusion criteria. After the data collection, a randomization (Epidat V4.0) 
of the selected subjects will be carried out to assign them to one of the intervention 
groups. 
 
Patients must present Achilles pathology and will be recruited through a network of 
physiotherapy clinics distributed across Spain. 
 
The physiotherapist responsible for their treatment will invite them to participate in the 
study by providing a QR code granting access to all relevant study documentation. This 
documentation will include a checkbox in which the patient must indicate that, after 
reading all the pertinent information, they consent to participate. Without this explicit 
consent, marked via the checkbox, participation will not be possible. 
 
Once consent is provided, the patient will gain access to three questionnaires to be 
completed at the same time: VISA-A, FAOS, and TENDINS-A. After 48 hours, they will 
receive a link to complete the TENDINS-A retest. 
 

 
When the participant has completed all four questionnaires (VISA-A, FAOS, TENDINS-
A, and the TENDINS-A retest), their participation in the study will be considered 
complete. 
 
The sample size will be calculated following COSMIN recommendations, aiming for a 
minimum of more than 100 participants to ensure excellent reliability. 
 
 
 

 
Statistical Analysis Plan (SAP) 
 
The statistical analyses required for the structural validation and assessment of the 
psychometric properties will be performed using IBM SPSS Statistics (v29.0.2.0), Jamovi 
(v2.3.28.0), or Microsoft Excel (v16.77.1).