Is There a Mechanistic Reason for the Response or Non-response to Isometric Exercise in Tendinopathy?

In early phase tendinopathy, isometric exercises are seen as ideal to provide pain relief to patients. This approach is mainly based on a paper by Rio et al (2016), where they found that isometric exercises of a certain load magnitude and time (5 repetitions of 45 second hold at 70% of maximum) gave 100% pain relief for 45 minutes in patients with patellar tendinopathy. This then helps patients to perform their more heavy load exercises during rehabilitation, which would otherwise be too painful.

Unfortunately, the study of Rio et al only consisted of 6 participants, and recent papers have contradicted the findings. In Achilles tendinopathy, plantar fasciopathy and lateral elbow tendinopathy, the pain relief was not consistently present, with "responders" and "non-responders" being found in these studies. Also, a study yet to be published (poster at conference), replicating Rio et al, also found a heterogeneous response, debunking the "one size fits all" approach that seemed to work.

However, in our understanding, isometric exercises do have a crucial role in early tendinopathy management, but the way the exercise is performed, in which position, what magnitude of load, time under tension, … has an important influence. The same protocol (5 repetitions of 45 second hold at 70% of maximum) might lead to big inter-individual differences. Therefore, there might be a mechanistic reason why some patients respond, and others do not.

Fortunately, the P.I. of this current trial application has recently optimized an ultrasound-based method to quantify local tendon deformation during exercises. The main purpose of this trial is therefore to evaluate the local tendon deformation pattern of patients with tendinopathy during isometric exercises and evaluate whether there is an interindividual difference in pattern between "responders" and "non-responders".

Study Overview

• Status: Unknown
• Conditions: Tendinopathy
• Intervention / Treatment: Diagnostic test: Evaluation of local tendon deformation

• Study Type: Observational
• Enrollment (Anticipated): 20

Contacts and Locations

Study Locations

• Belgium
  • Vlaams-Brabant
    • Leuven, Vlaams-Brabant, Belgium, 3000
      • University Hospitals
      • Contact: Stijn Bogaerts

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: N/A
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients visiting the sports medicine consultation of the University Hospitals and presenting with complaints of patellar tendinopathy will be screened for eligibility.

Description

Inclusion Criteria:

- Clinical diagnosis of patellar tendinopathy, consisting of

• pain located at the proximal part of the patellar tendon
• painful at palpation the proximal part of the patellar tendon
• Numeric Rating Scale > 1/10 with squat on decline (20°) board

Exclusion Criteria:

• previous treatment for patellar tendinopathy
• rupture of patellar tendon on ultrasound
• unclear differential diagnosis with patellofemoral pain
• concomitant neuromuscular disorders

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Responders; Patients suffering from patellar tendinopathy who have complete pain resolution after performing isometric exercises.	Diagnostic test: Evaluation of local tendon deformation; Ultrasound-based speckle tracking to evaluate the local tendon tissue displacement during isometric exercise.
Non-responders; Patients suffering from patellar tendinopathy who do not have complete pain resolution after performing isometric exercises.	Diagnostic test: Evaluation of local tendon deformation; Ultrasound-based speckle tracking to evaluate the local tendon tissue displacement during isometric exercise.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Local tendon tissue displacement in three layers of the tendon (deep, middle and superficial layer); as measured by ultrasound-based speckle tracking	Millimeter	Immediately during isometric exercise

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Non-uniform displacement; as measured by ultrasound-based speckle tracking	% (measure for relative displacement of the superficial layer of the tendon versus the deep layer, and then divided by the mean total displacement of the three layers combined)	Immediately during isometric exercise

Collaborators and Investigators

• Sponsor: Universitaire Ziekenhuizen KU Leuven

Study record dates

Study Major Dates

• Study Start (Anticipated): August 1, 2019
• Primary Completion (Anticipated): January 1, 2020
• Study Completion (Anticipated): July 1, 2020

Study Registration Dates

• First Submitted: February 13, 2019
• First Submitted That Met QC Criteria: February 18, 2019
• First Posted (Actual): February 21, 2019

Study Record Updates

• Last Update Posted (Actual): February 22, 2019
• Last Update Submitted That Met QC Criteria: February 20, 2019
• Last Verified: February 1, 2019

More Information

Terms related to this study

• Keywords: ultrasound; isometric; speckle; patellar
• Additional Relevant MeSH Terms: Wounds and Injuries; Musculoskeletal Diseases; Muscular Diseases; Tendon Injuries; Tendinopathy
• Other Study ID Numbers: SBogaerts

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