Patellar TendinopathyNCT04550013
Blood Flow Restriction Training for Treatment of Chronic Patellar Tendinopathy
A study testing Heavy-Slow Resistance training and Low-Load Blood Flow Restriction training in people with Patellar Tendinopathy and Jumper's Knee, run by Bispebjerg Hospital at 1 site in Denmark.
Trial summary
The purpose of this study is to investigate the clinical and functional outcome of a 12-week rehabilitation regime consisting of Low-Load Blood Flow Restriction compared to Heavy-Slow Resistance training in male patients with chronic unilateral patellar tendinopathy. Read more about this study
- Who is it for?
- Ages 18 to 70 years, men only
- Conditions the study is for
- Patellar Tendinopathy, Jumper's Knee
- What is being tested?
- Heavy-Slow Resistance training and Low-Load Blood Flow Restriction training
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteDenmark
- Study dates
- 1 Aug 2020to 23 Sep 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 70 years
- Men only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Unilateral patellar tendinopathy
- Chronic (symptoms >3 months)
- Pain of ≥ 4 during preferred sporting activity on the numerical pain rating scale (NRS; with 0 being no pain and 10 being the worst imaginable pain)
- Ultrasonographical tendon swelling
- Ultrasonographical hypo-echoic area with doppler
Who cannot join
- Bilateral tendinopathy
- Cardiovascular diseases
- Diabetes
- Smoking
- Previous surgery or trauma to the knee joint with an effect on the presenting clinical condition
- Participants must not have been enrolled in a resistance based-rehabilitation program for the affected patellar tendon within the previous three months
- Previous corticosteroid injection for patellar tendinopathy
Trial locations and contacts
1 site in 1 country.
Denmark1 site
Department of Physical and Occupational Therapy / Institute of Sports Medicine Copenhagen, Bispebjerg Hospital
Copenhagen, 2400
About this study
Official title: The Effect of Low-Load Resistance Training With Blood Flow Restriction for Treatment of Chronic Patellar Tendinopathy - A Randomized Clinical Trial
The purpose of this study is to investigate the clinical and functional outcome of a 12-week rehabilitation regime consisting of Low-Load Blood Flow Restriction compared to Heavy-Slow Resistance training in male patients with chronic unilateral patellar tendinopathy.
Read the detailed description
Chronic tendinopathy represents a considerable problem in both elite and recreational athletes, and symptoms may affect athletic performance and reduce or even result in retirement from sports participation. The current best treatment is considered to be heavy-slow resistance training (HSRT); however, not all patients are able to cope with heavy exercise loads. Therefore, low-load strength training performed under partial blood flow restriction may be a clinically relevant rehabilitation tool.
This project aims to investigate a new innovative intervention to treat chronic unilateral patellar tendinopathy in male individuals using strength training with low-load muscle contractions performed under partial blood flow restriction (LL-BFR), and to compare the resulting treatment outcome to that of the current best practice (HSRT). Specifically, the effect of LL-BFR will be investigated using a randomized controlled trial design with two groups; 1) a low-load blood flow restriction training program, and 2) a heavy-load slow strength training program. A total sample size of 36 participants are needed when assuming a 10 % dropout.
The training protocol consist of three weekly training sessions during a 12-week rehabilitation period. The primary outcome is measured using the Single-Leg Decline Squat at 12-week.
If LL-BFR proves to be an effective treatment strategy for tendinopathy, it can easily be implemented in daily clinical practice.
- Conditions
- Patellar Tendinopathy, Jumper's Knee
- Being tested
- Heavy-Slow Resistance training, Low-Load Blood Flow Restriction training
- Keywords
- Patellar tendinopathy, Overuse Injury, Rehabilitation
- Medical subject headings
- Cumulative Trauma Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Heavy-Slow Resistance trainingOther
Resistance training for knee extensors. The exercise will be performed at 80% of 1 RM and slowly (6 s/repetition).
Low-Load Blood Flow Restriction trainingOther
Resistance training for knee extensors. The exercise will be performed at 30% of 1 RM and with a relative Artery Occlusion Pressure of 80%
| Study group | Role | What they receive |
|---|---|---|
| Heavy-Slow Resistance training | Active comparator | Heavy-Slow Resistance training. Three times weekly for 12 weeks. Receives: Other: Heavy-Slow Resistance training |
| Low-Load Blood Flow Restriction training | Experimental | Low-Load Blood Flow Restriction training. Three times weekly for 12 weeks Receives: Other: Low-Load Blood Flow Restriction training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline - 12 weeks using the clinical functional test Single-Leg Decline Squat measured on the Numerical Rating Scale (NRS; 0= no pain, 10 = worst imaginable pain)
Single-Leg Decline Squat is a reliable patellar tendon pain provocation test used to assess pain during function.
Measured: Baseline-12 weeks.
Secondary outcomes (12)
Single-Leg Decline Squat test
A reliable patellar tendon pain provocation test, will be used to assess pain during function using the Numerical Rating Scale (NRS; 0= no pain, 10 = worst imaginable pain)
Measured: Baseline, 3, 6 weeks + 1 year follow-up
Pain rating on Numeric Rating Scale (NRS; 0 = no pain; 10 = worst imaginable pain) during training.
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Self-reported activity level of sporting activities (hours/week)
Participants will self-report how many hours a week they are performing sporting activities: We will monitor to see if they decrease, maintain or increase hours per week of sporting activity
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Doppler activity using Ultrasonography power Doppler
Using Ultrasonography, we will measure Doppler activity within the affected tendon and use ImageJ for the analysis
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Tendon thickness measured using Ultrasonography
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Muscle cross-sectional area measured using Ultrasonography
We will measure the muscle thickness of vastus lateralis using ultrasonography
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Muscle structure measured by MRI
Measured: Baseline and 12 weeks
Tendon dimensions measured by MRI
Measured: Baseline and 12 weeks
Isometric Muscle Strength
Maximal muscle strength of the knee extensors is obtained during a maximal isometric voluntary contractions
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Pain Pressure Threshold
Measured by a handheld pressure algometry at most painful site, Apex Patellar, Tibialis Anterior and Extensor Carpi Radialis.
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Adverse events
Participants will self-report adverse events during intervention period and at 1 year follow-up
Measured: Baseline-12 weeks + 1 year follow-up
Victorian Institute of Sports Assessment - Patellar Tendinopathy
The VISA-P is a questionnaire that assesses symptoms, simple test of function, and the ability to play sports. Max score for asymptomatic is 100 and worst score is 0
Measured: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Sep 2020
- Study start1 Aug 2020
- Primary completion30 Dec 2022
- Study completion23 Sep 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Patellar TendinopathyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 36 participants (actual)
Sponsor and investigators
- Lead sponsor
- Bispebjerg Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- University College Absalon, Danske Fysioterapeuter
- Responsible party
- Principal investigator, Mikkel Holm Hjortshøj Jensen, Bispebjerg Hospital
- Investigators
- Mikkel Holm Hjortshøj Jensen, MSc, Principal investigator, Bispebjerg Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04550013
- Sponsor's protocol ID
- A2359
- Status last verified
- Jan 2023
- First submitted
- 20 Aug 2020
- Last updated
- 18 Jan 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Hjortshoej MH, Juneja H, Svensson RB, Herzog RB, Lundgaard-Nielsen M, Nielsen FK, Wulff MW, Olsen AE, Nybing JD, Hansen P, Petersen J, Kjaer M, Aagaard P, Magnusson SP, Couppe C. Effect of Low-Load Blood-Flow Restricted Training Versus Heavy Slow Resistance Training in Unilateral Patellar Tendinopathy: A Randomized Clinical Trial. Scand J Med Sci Sports. 2025 Dec;35(12):e70186. doi: 10.1111/sms.70186.
PubMed 41452311
Study at a glance
From the registry record, last updated by the sponsor on 18 Jan 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Low-Load Resistance Training With Blood Flow Restriction for Treatment of Chronic Patellar Tendinopathy - A Randomized Clinical Trial
- ClinicalTrials.gov ID
- NCT04550013
- Acronym / sponsor ID
- A2359
- Conditions
- Patellar Tendinopathy, Jumper's Knee
- Keywords
- Patellar tendinopathy, Overuse Injury, Rehabilitation
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 36 participants (actual)
- Lead sponsor
- Bispebjerg HospitalUniversity, hospital or other
- Collaborators
- University College Absalon, Danske Fysioterapeuter
- Study start
- 1 Aug 2020 (actual)
- Primary completion
- 30 Dec 2022 (actual)
- Study completion
- 23 Sep 2023 (estimated)
- First posted
- 16 Sep 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to investigate the clinical and functional outcome of a 12-week rehabilitation regime consisting of Low-Load Blood Flow Restriction compared to Heavy-Slow Resistance training in male patients with chronic unilateral patellar tendinopathy.
Detailed description
Chronic tendinopathy represents a considerable problem in both elite and recreational athletes, and symptoms may affect athletic performance and reduce or even result in retirement from sports participation. The current best treatment is considered to be heavy-slow resistance training (HSRT); however, not all patients are able to cope with heavy exercise loads. Therefore, low-load strength training performed under partial blood flow restriction may be a clinically relevant rehabilitation tool.
This project aims to investigate a new innovative intervention to treat chronic unilateral patellar tendinopathy in male individuals using strength training with low-load muscle contractions performed under partial blood flow restriction (LL-BFR), and to compare the resulting treatment outcome to that of the current best practice (HSRT). Specifically, the effect of LL-BFR will be investigated using a randomized controlled trial design with two groups; 1) a low-load blood flow restriction training program, and 2) a heavy-load slow strength training program. A total sample size of 36 participants are needed when assuming a 10 % dropout.
The training protocol consist of three weekly training sessions during a 12-week rehabilitation period. The primary outcome is measured using the Single-Leg Decline Squat at 12-week.
If LL-BFR proves to be an effective treatment strategy for tendinopathy, it can easily be implemented in daily clinical practice.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Heavy-Slow Resistance training | Active comparator | Other: Heavy-Slow Resistance trainingHeavy-Slow Resistance training. Three times weekly for 12 weeks. |
| Low-Load Blood Flow Restriction training | Experimental | Other: Low-Load Blood Flow Restriction trainingLow-Load Blood Flow Restriction training. Three times weekly for 12 weeks |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Unilateral patellar tendinopathy
- Chronic (symptoms >3 months)
- Pain of ≥ 4 during preferred sporting activity on the numerical pain rating scale (NRS; with 0 being no pain and 10 being the worst imaginable pain)
- Ultrasonographical tendon swelling
- Ultrasonographical hypo-echoic area with doppler
Key exclusion criteria (7 listed)
- Bilateral tendinopathy
- Cardiovascular diseases
- Diabetes
- Smoking
- Previous surgery or trauma to the knee joint with an effect on the presenting clinical condition
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Heavy-Slow Resistance trainingResistance training for knee extensors. The exercise will be performed at 80% of 1 RM and slowly (6 s/repetition). | Other | Heavy-Slow Resistance training |
| Low-Load Blood Flow Restriction trainingResistance training for knee extensors. The exercise will be performed at 30% of 1 RM and with a relative Artery Occlusion Pressure of 80% | Other | Low-Load Blood Flow Restriction training |
Primary outcome
Change from baseline - 12 weeks using the clinical functional test Single-Leg Decline Squat measured on the Numerical Rating Scale (NRS; 0= no pain, 10 = worst imaginable pain)
Time frame: Baseline-12 weeks.
Single-Leg Decline Squat is a reliable patellar tendon pain provocation test used to assess pain during function.
12 secondary outcomes
Single-Leg Decline Squat test
Time frame: Baseline, 3, 6 weeks + 1 year follow-up
Pain rating on Numeric Rating Scale (NRS; 0 = no pain; 10 = worst imaginable pain) during training.
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Self-reported activity level of sporting activities (hours/week)
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Doppler activity using Ultrasonography power Doppler
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Tendon thickness measured using Ultrasonography
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Muscle cross-sectional area measured using Ultrasonography
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Muscle structure measured by MRI
Time frame: Baseline and 12 weeks
Tendon dimensions measured by MRI
Time frame: Baseline and 12 weeks
Isometric Muscle Strength
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Pain Pressure Threshold
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Adverse events
Time frame: Baseline-12 weeks + 1 year follow-up
Victorian Institute of Sports Assessment - Patellar Tendinopathy
Time frame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jan 2023.
- Derived from this study: PubMed 41452311Hjortshoej MH, Juneja H, Svensson RB, Herzog RB, Lundgaard-Nielsen M, Nielsen FK, Wulff MW, Olsen AE, Nybing JD, Hansen P, Petersen J, Kjaer M, Aagaard P, Magnusson SP, Couppe C. Effect of Low-Load Blood-Flow Restricted Training Versus Heavy Slow Resistance Training in Unilateral Patellar Tendinopathy: A Randomized Clinical Trial. Scand J Med Sci Sports. 2025 Dec;35(12):e70186. doi: 10.1111/sms.70186.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mikkel Holm Hjortshøj Jensen, MSc principal investigator
Bispebjerg Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Heavy-Slow Resistance training and Low-Load Blood Flow Restriction training in people with Patellar Tendinopathy and Jumper's Knee, run by Bispebjerg Hospital at 1 site in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 18 Jan 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline - 12 weeks using the clinical functional test Single-Leg Decline Squat measured on the Numerical Rating Scale (NRS; 0= no pain, 10 = worst imaginable pain) (time frame: Baseline-12 weeks.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04550013, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Jan 2023.