Early Implementation of Plyometric Exercises in the Rehabilitation of Individuals Suffering From Lower-Extremity Tendinopathies

NCT06774547 | Recruiting

• 1 other identifier: N-20240042
• Study Type: interventional
• Target: 120
• Locations: 1 country
• Sites: 1

Brief Summary

This clinical trial aims to compare the effectiveness of an early plyometric exercise approach with traditional heavy, slow resistance training in treating tendinopathies of the Achilles tendon, patellar tendon, and plantar fascia. These conditions, commonly seen in general and rheumatology practices, cause pain, reduced function, and stiffness, often leading to prolonged recovery and incomplete return to full physical activity. The study hypothesizes that introducing plyometric exercises early in rehabilitation will improve jump function after 12 weeks and reduce re-injury rates within 52 weeks compared to traditional methods. The study is a randomized clinical trial including 120 participants aged 18-50 with tendinopathy in one of the targeted areas. Participants must regularly engage in running or jumping sports, have symptoms for at least three months, and meet other inclusion criteria. Exclusion criteria include recent surgery or specific medical conditions. Both groups will perform exercises three times weekly for 12 weeks, tailored to their tendinopathy. The intervention group will add progressive plyometric exercises to the standard strength training performed by the control group. Plyometric training will consist of three levels, with patients self-assessing readiness to progress. The primary outcome is the change in the plyometric quotient, a measure of functional ability, based on a jump test using a force platform at 0 and 12 weeks. Secondary outcomes include dynamic strength, jump height, patient-reported symptoms (via questionnaires), return to sport, training compliance, adverse events, pain thresholds, re-injury rates, and psychological readiness for sports. Assessments will occur at baseline, 12 weeks, and 52 weeks.

Conditions

Achilles Tendinopathy; Patellar Tendinopathy; Plantar Fasciopathy

Outcome Measures

Primary Outcomes (1)

• Plyometric quotient

  The plyometric quotient is calculated by dividing the flight time by the contact time during single-leg hops and has good to excellent reliability. The test is performed on a force plate where the participant is instructed to perform 25 hops at a frequency of around two hops per second standing on their affected limb (or most symptomatic if they have bilateral symptoms). The first three and last two hops are excluded, which means that 20 hops are used to assess the flight time and contact time.

  From baseline to the 12-week follow-up

Secondary Outcomes (15)

• Plyometric quotient

  From baseline to the 52-week follow-up

• Dynamic strength

  Baseline to the 12-week and 52-week follow-ups

• Drop countermovement jump height

  From baseline to the 12-week and 52-week follow-ups

• Drop countermovement contact time

  From baseline to the 12-week and 52-week follow-ups

• Victorian Institute of Sports Assessment - Achilles (VISA-A)

  Baseline to the 12-week and 52-week follow-ups

Study Arms (2)

Plyometrics

EXPERIMENTAL

Performing both heavy-slow resistance training and the plyometric protocol

Other: Heavy-slow resistance training; Other: Plyometric exercise

Control

ACTIVE COMPARATOR

Perform heavy-slow resistance training

Other: Heavy-slow resistance training

Interventions

Heavy-slow resistance training OTHER

Heavy-slow resistance training consists of a progressive protocol of dynamic exercises where the relative load increases over time from a weight that can only be lifted 15 times (i.e., 15 repetition maximum) during the first week to a relative load of 6 repetition maximum from Week 9 to 12. The exercises are performed unsupervised three days per week separated by a minimum of 48 hours. There are two exercises that are performed for four sets separated by a 2-minute rest. Participants with Achilles tendinopathy or plantar fasciopathy perform seated and standing weighted heel raises and participants with patellar tendinopathy perform a free-standing squat and a seated leg press. Tolerable pain during the exercises is allowed.

Control; Plyometrics

Plyometric exercise OTHER

The progressive plyometric programme consists of three different levels and is performed unsupervised three times per week separated by a minimum of 48 hours. Each level consists of several exercise sets that are separated by 2-minute rest intervals. Participants' self-evaluated readiness to progress to a higher level will guide the progression. Level 1 includes free-standing double-legged plyometric exercises where they push off the ground and lift their heels while maintaining contact with it. If the participant feels they can do more, they will progress to Level 2, where participants increase the relative load during the dynamic exercises and start performing plyometric double-legged jumps. At the highest level, Level 3, the relative load during the exercises is further increased, and the plyometric exercises are to be performed as single-legged hops. Tolerable pain during the exercises is allowed.

Plyometrics

Eligibility Criteria

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

You may qualify if:

• participants are required to have performed either recreational running or participated in sports that include running or jumping activities (e.g., football, basketball, handball, volleyball) at least once per week for at least three months immediately prior to pain onset
• have had symptoms for at least three months
• have pain/soreness with palpation of the tendon/fascia
• mean pain during the past week of at least 2 on a 0 to 10 Numerical Rating Scale
• pain during a pain provocation test (patellar tendinopathy: five single-legged decline squats, Achilles tendinopathy and plantar fasciopathy: ten single-legged heel raises)

You may not qualify if:

• previous lower-extremity surgery
• other lower-extremity musculoskeletal conditions that have required treatment by a healthcare professional during the past three months
• pregnancy
• diabetes
• history of inflammatory systemic diseases (e.g., rheumatoid arthritis or spondylarthritis)
• having received an injection with corticosteroid within the past six months.

Sponsors & Collaborators

• Aalborg University: lead
• Department of Physiotherapy, University College of Northern Denmark: collaborator

Study Sites (1)

University College of Northern Denmark

Aalborg, 9220, Denmark

RECRUITING

MeSH Terms

Interventions

Plyometric Exercise

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Central Study Contacts

Henrik Riel, PhD

CONTACT

0045 72691014; heri@ucn.dk

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: Postdoc

Study Record Dates

• First Submitted: January 3, 2025
• First Posted: January 14, 2025
• Study Start: September 18, 2025
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): January 1, 2028
• Last Updated: March 4, 2026

Record last verified: 2026-03

Locations

DK (1)