Effects of Resistance Training on Patellar Tendon Properties in People With Patellar Tendinoapthy

NCT07682051 | Enrolling By Invitation

• 1 other identifier: GZ. 39/255/63
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to investigate the effects of two different resistance training interventions on the structural, morphological, mechanical, and functional properties of the thigh muscles (in particular the quadriceps femoris) and the patellar tendon, in participants with current patellar tendinopathy.

Conditions

Patellar Tendinopathy

Outcome Measures

Primary Outcomes (8)

• Tendon Thickness

  Anteroposterior thickness of the patellar tendon (in milimiters) measures by B-Mode Ultrasound (Aixplorer V12.3 Supersonic Imaging, France) with a SuperLinear 15-4 MHz probe. Three images at the same position will be taken for further analysis with the software ImageJ.

  From enrollment to the end of training at 12 weeks

• Tendon sitffness

  Stiffness of the patellar tendon (in kilopascal) will be measured with Shear-Wave Elastrography (Aixplorer V12.3, Supersonic Imaging, France). The measurement site is 0.5cm from the patellar apex, and five videos of 15 seconds will be recorded for further analysis with Matlab.

  From enrollment to the end of training at 12 weeks

• Tendon CSA

  Cross-sectional area of the patellar tendon (in centimiters) on its proximal, middle and distal part, will be measured with B-Mode Ultrasound (Aixplorer V12.3, Supersonic Imaging, France). Three images per site, accounting for a total of 9 images, will be taken for further analysis with the software ImageJ.

  From enrollment to the end of training at 12 weeks

• Fascicle length

  Length of the fascicles of the vastus lateralis muscle (in centimiters) will be measures with Extended Field of View (Panoramic) B-Mode Ultrasound (Aixplorer V12.3, Supersonic Imaging, France). Five images will be taken for further analysis with the software ImageJ.

  From enrollment to the end of training at 12 weeks

• Muscle Strength

  Maximum voluntary isometric torque of the knee extensors (in newton per meters) will be measured with the Isomed2000, Germany device. Three trials will be performed, with three minutes of rest in between, and the trial with the maximum peak torque will be taken for analysis.

  From enrollment to the end of training at 12 weeks

• 1 repetition maximum

  Maximum strength of the leg press and knee extension exercises (in kilograms) will be measured with the leg press and knee extension devices (compass540, Physiomed, Germany). Participants will perform repetitions with increasing weights, until they can perform a maximum of eight repetitions with a specific weight. This weight will be then used to estimate their maximum 1RM, to further calculate the training loads.

  From enrollment to the end of training at 12 weeks

• Overall Pain

  Pain assessed at rest and during a single-leg-decline squat (SLDS) will be assessed with the numerical rating scale of 11 points called Visual Analogue Scale (VAS). Higher values mean higher pain levels.

  From enrollment to the end of training at 12 weeks

• Functionality

  Functionality assessed with the VISA-P Questionnaire. This questionnaire includes 10 questions with a score from 0 to 10, for a maximum questionnaire score of 100 points. Higher scores mean better functionality.

  From enrollment to the end of training at 12 weeks

Secondary Outcomes (5)

• Tendon Neovascularization

  From enrollment to the end of training at 12 weeks

• Young's Modulus

  From enrollment to the end of training at 12 weeks

• Muscle Thickness

  From enrollment to the end of training at 12 weeks

• Muscle Stiffness

  From enrollment to the end of training at 12 weeks

• Jump Height

  From enrollment to the end of training at 12 weeks

Study Arms (2)

Eccentric Training

EXPERIMENTAL

Participants between 18 and 50 years of age with patellar tendinopathy who will receive the eccentric intervention only.

Other: Eccentric Training

Heavy-Slow Resistance Training

EXPERIMENTAL

Participants between 18 and 50 years of age with patellar tendinopathy who will receive the heavy-slow resistance training intervention only.

Other: Heavy-Slow Resistance Training

Interventions

Eccentric Training OTHER

The intervention consists of 12 weeks of resistance training, with a frequency of three times per week. Participants in this group will perform two exercises on a leg press and knee extension machine at their own training facility. This intervention has a repetition time of four seconds, with only the eccentric phase of the movement being performed. They will rest between two and three minutes between sets and will perform the exercises as long as their pain level is less than or equal to four on a pain scale from 0-10. The training parameters are the following, applying to both leg press and knee extension exercises: Week 1: 3 sets of 15 repetitions at 60% of their 1-repetition maximum (1RM) Week 2 and 3: 3 sets of 12 repetitions at 70% of their 1RM Week 4 and 5: 3 sets of 10 repetitions at 75% of their 1RM Week 6 to 12: 4 sets of 8 repetitions at 80% of their 1RM.

Also known as: ECC

Eccentric Training

Heavy-Slow Resistance Training OTHER

The intervention consists of 12 weeks of resistance training, with a frequency of three times per week. Participants in this group will perform two exercises on a leg press and knee extension machine at their own training facility. This intervention has a repetition time of four seconds, of which two seconds will be spent on the concentric phase and two seconds on the eccentric phase of the movement being performed. They will rest between two and three minutes between sets and will perform the exercises as long as their pain level is less than or equal to four on a pain scale from 0-10. The training parameters are the following, applying to both leg press and knee extension exercises: Week 1: 3 sets of 15 repetitions at 60% of their 1-repetition maximum (1RM) Week 2 and 3: 3 sets of 12 repetitions at 70% of their 1RM Week 4 and 5: 3 sets of 10 repetitions at 75% of their 1RM Week 6 to 12: 4 sets of 8 repetitions at 80% of their 1RM.

Also known as: HSRT

Heavy-Slow Resistance Training

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Between 18 and 50 years of age
• Pain at the inferior pole of the patella, longer than 3 months
• Active lifestyle (sport/exercise minimum 3 times per week)
• No previous injuries or surgeries on the affected leg

You may not qualify if:

• Corticoid injections in the last 6 months
• Current intake of pain or non-steroidal anti-inflammatory drugs
• Additional tendinopathy treatments in the last 6 months (i.e., physical therapy, shock-wave therapy, drug interventions, etc.)
• Neuromuscular or cardiovascular associated diseases or conditions

Sponsors & Collaborators

• University of Graz: lead

Study Sites (1)

University of Graz

Graz, Styria, 8010, Austria

Location

Study Officials

• Josefina Manieu Seguel, M.Sc.

  University of Graz

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Research Assistant - PhD Student

Model Details: The study is designed as a randomized controlled trial (RCT). This means the participants will be randomly assigned to one of two intervention groups: * Eccentric group: the intervention group will perform an eccentric resistance training protocol for 12 weeks. This means the focus is on the deceleration or "return" part of the movement. * Heavy-slow resistance training: this group will perform both the concentric and the eccentric parts of the exercises for 12 weeks. In simple words, a closer-to-normal strength training protocol.

Study Record Dates

• First Submitted: June 23, 2026
• First Posted: July 2, 2026
• Study Start: July 1, 2026
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): November 30, 2027
• Last Updated: July 2, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: The IPD and supporting information will be available starting June 2026, archived and available to the specific members mentioned above for a period of 10 years (June 2036).
• Access Criteria: The supervisor and the senior postdoctoral researcher will have access to the information. They will have access to the metrics of the outcome variables of each participant. This includes: tendon stiffness, tendon thickness, tendon cross-sectional area, tendon neovascularization, tendon Young's modulus, muscle thickness, muscle stiffness, fascicle length, strength test results, jump height, pain scores, and questionnaire scores. They will have access through a secure University server that stores the data under the principal investigator's name, which allows selective access to specified people.

Locations

AU (1)