An interventional study of Eccentric exercise and extracorporeal shock wave therapy and Beta-hydroxy-beta-methylbutyrate (HMB) in Patellar Tendinopathy, sponsored by Universidad Complutense de Madrid. Not yet recruiting at 1 site in Spain. Open to participants aged 18 Years to 49 Years. Per ClinicalTrials.gov, last updated 2026-03-12.
Sponsored by Universidad Complutense de Madrid · Not applicable, Interventional, and Treatment
This randomized, double-blind, placebo-controlled clinical trial evaluates the effects of oral beta-hydroxy-beta-methylbutyrate (HMB) supplementation combined with an eccentric exercise and extracorporeal shockwave rehabilitation program on pain, tendon morphology, and neuromuscular performance in athletes with patellar tendinopathy.
Thirty athletes with a confirmed diagnosis of patellar tendinopathy are randomized to receive either HMB supplementation (3 g/day) or placebo during an 8-week rehabilitation program. Participants are evaluated at baseline, week 4, and week 8.
The primary outcome is pain and functional limitation assessed using the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire. Secondary outcomes include patellar tendon thickness measured by ultrasound imaging, countermovement jump (CMJ) performance, and neuromuscular performance variables derived from an incremental squat test using a linear position transducer.
The aim of the study is to determine whether HMB supplementation enhances clinical recovery and neuromuscular performance when combined with a standardized rehabilitation program compared with placebo.
Patellar tendinopathy is a degenerative tendon disorder frequently observed in athletes involved in jumping and running sports. The condition is characterized by localized tendon pain, functional impairment, and structural alterations of the patellar tendon. Standard rehabilitation programs commonly include eccentric exercise protocols and extracorporeal shockwave therapy to promote tendon adaptation and pain reduction.
Beta-hydroxy-beta-methylbutyrate (HMB), a metabolite of the amino acid leucine, has been associated with anti-catabolic effects and improved muscle recovery. HMB supplementation may potentially enhance neuromuscular adaptations and recovery during rehabilitation programs.
This study evaluates the effects of HMB supplementation when combined with a standardized rehabilitation program including eccentric exercise and extracorporeal shockwave therapy in athletes with patellar tendinopathy.
This randomized, double-blind, placebo-controlled clinical trial includes 30 athletes aged 18 to 49 years with clinically diagnosed patellar tendinopathy. Participants are randomly assigned to one of two groups:
HMB Group: Participants receive oral HMB supplementation (3 g/day) combined with eccentric exercise and extracorporeal shockwave therapy.
Placebo Group: Participants receive placebo capsules (sucrose) combined with the same eccentric exercise and extracorporeal shockwave therapy program.
The intervention lasts 8 weeks. Assessments are performed at baseline, week 4, and week 8.
The primary outcome measure is the VISA-P questionnaire, which assesses pain and functional limitations related to patellar tendinopathy. Secondary outcome measures include patellar tendon thickness measured by ultrasound imaging, countermovement jump (CMJ) performance, and neuromuscular performance variables obtained from an incremental squat test using a linear position transducer, including peak power, peak power relative to body mass, and mean velocity at peak power.
Exercise sessions follow a structured eccentric decline squat protocol combined with periodic extracorporeal shockwave therapy sessions using a Storz Medical MP100 device.
The objective of the study is to determine whether HMB supplementation improves clinical outcomes, tendon thickness, and neuromuscular performance compared with placebo when both groups follow the same rehabilitation program.
397 studies on the registry are indexed under Tendinopathy; 77 are open to participants now.
This study's planned enrollment of 30 is below the median of 48 across 332 interventional studies indexed under Tendinopathy.
Browse Tendinopathy studies →Universidad Complutense de Madrid is the lead sponsor of 206 studies on the registry; 64 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants receive beta-hydroxy-beta-methylbutyrate (HMB) supplementation in combination with a rehabilitation program consisting of eccentric exercise and extracorporeal shock wave therapy.
Other: Eccentric exercise and extracorporeal shock wave therapy · Dietary Supplement: Beta-hydroxy-beta-methylbutyrate (HMB)
Participants receive placebo supplementation in combination with a rehabilitation program consisting of eccentric exercise and extracorporeal shock wave therapy.
Other: Eccentric exercise and extracorporeal shock wave therapy
Participants undergo a standardized rehabilitation program consisting of eccentric exercise and extracorporeal shock wave therapy.
Participants ingest 3 g/day of beta-hydroxy-beta-methylbutyrate (HMB) in capsule form, administered 60 minutes before each eccentric training session during the 8-week intervention period.
VISA-P Score
Change in pain and functional limitation assessed using the Victorian Institute of Sport Assessment-Patella (VISA-P) questionnaire. Scores range from 0 to 100, with higher scores indicating better function and lower pain levels.
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Patellar tendon thickness
Change in patellar tendon thickness (mm) measured by ultrasound imaging using a standardized longitudinal scanning protocol
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Countermovement Jump (CMJ)
hange in countermovement jump (CMJ) height measured in centimeters using a contact platform. Participants will perform three maximal attempts, and the highest value will be recorded
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Peak Power (PP) during squat test
Change in peak power (PP) measured in watts during an incremental squat test using a linear position transducer.
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Peak Power Relative to Body Mass (PPkg)
Change in peak power relative to body mass (PPkg) measured in watts per kilogram during an incremental squat test using a linear position transducer.
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Mean Velocity at Peak Power (PPmv)
Change in mean velocity at peak power (PPmv) measured in meters per second during an incremental squat test using a linear position transducer.
Time frame: Baseline (PRE), Week 4 (INT), and Week 8 (POST)
Plan to share: No
Start is estimated for Mar 2026; primary completion for Jun 2026, 3 months later.
Of 174 non-industry interventional studies with no phase under Tendinopathy, half reached primary completion within 20 months of starting (the median), counting those still running; a quarter within 7 and three quarters within 37. This study's planned 3 months is below that.
Counting every sponsor, half of 183 studies reached it within 20 months; a quarter within 7 and three quarters within 37.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Feb 2026. You cannot join it, but the record below documents what was studied.
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