Presence of Pain Shows Greater Effect Than Tendon Structural Alignment During Landing Dynamics

The goal of this observational study is to investigate the relationship between temporal, kinetic, and kinematic jump variables and patellar tendons' structure in athletes. The main research questions are:

Does the structure of the patellar tendon relate to the temporal, kinetic, and kinematic variables of different jumps?

To answer these questions, participants will undergo a UTC (Ultrasound Tissue Characterization) scan of the patellar tendon and perform two vertical jump: a countermovement jump and tuck jump test.

Study Overview

• Status: Completed
• Conditions: Athletes; Patellar Tendon

• Study Type: Observational
• Enrollment (Actual): 39

Contacts and Locations

Study Locations

• Portugal
  • Porto, Portugal, 4200-072
    • Escola Superior de Saúde do Instituto Politécnico do Porto

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

The target population for this study consisted of volleyball athletes aged 18 to 35, of both sexes.

Description

Inclusion Criteria:

• aged between 18-30 years;
• competing in the highest-level Portuguese volleyball league with a minimum of 10 years of volleyball practice.

Exclusion Criteria:

• presence of injuries or discomfort that impeded maximal jumping tests;
• history of surgery within the last 12 months;
• illness during data collection

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
Athletes; Included volunteer participants were aged between 18-30 years, competing in the highest-level Portuguese volleyball league with a minimum of 10 years of volleyball practice. Participants were excluded in presence of injuries or discomfort that impeded maxi- mal jumping tests, history of surgery within the last 12 months or illness during data collection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Tendon Structure	Ultrasound Tissue Characterization (UTC) captures tendon structure and quantifies the number of altered fibers. This technology classifies tendon structure into four echo types, reflecting tendon integrity and fibrillar organization. Data collection for the patellar tendon will be conducted with participants seated, hips and knees at 90° flexion, and feet supported on a stable surface. For the Achilles tendon, the participants will be lying down with ankle in neutral position. This positioning ensures the probe is aligned transversely to the tendons, enabling the acquisition of optimal ultrasound images without anisotropy. Ultrasound parameters will be standardized for all scans: a 40-second B-mode ultrasound using a 7-10 Hz linear transducer, with the probe attached to a tracking device that moves automatically along the tendon's perpendicular axis, capturing consecutive images at 0.2 mm intervals. A single scan of the tendons will be performed for each knee.	Baseline
Jump Variables	The data collection protocol includes the following tasks: countermovement jump and tuck jump test. Kinematic variables will be analyzed by recording the spatial positions of reflective markers placed on specific anatomical regions. Data will be captured using the Qualisys Motion Capture System (version 2021.2). Ground reaction forces will be measured using a force platform connected to a signal amplifier. The platform records the three components of ground reaction forces-anteroposterior, mediolateral, and vertical-via four sensors. The image capture hardware is connected to the Qualisys USB Analog Acquisition interface, synchronizing temporal, kinetic, and kinematic data with the Qualisys Track Manager (QTM) software.	baseline

Collaborators and Investigators

• Sponsor: Escola Superior de Tecnologia da Saúde do Porto
• Collaborators: Universitat Internacional de Catalunya

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2023
• Primary Completion (Actual): July 31, 2023
• Study Completion (Actual): July 31, 2023

Study Registration Dates

• First Submitted: February 10, 2025
• First Submitted That Met QC Criteria: February 10, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 14, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: patellar tendon; jump performance; UTC; tendon structure
• Other Study ID Numbers: FIS-2022-06

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
• product manufactured in and exported from the U.S.: No