Clinical trial NCT04550013: Blood Flow Restriction Training for Treatment of Chronic Patellar Tendinopathy
Official title: The Effect of Low-Load Resistance Training With Blood Flow Restriction for Treatment of Chronic Patellar Tendinopathy - A Randomized Clinical Trial
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Patellar Tendinopathy
Jumper's Knee
Keywords: Patellar tendinopathy
Overuse Injury
Rehabilitation
Lead sponsor: Bispebjerg Hospital
Sponsor class: OTHER
Collaborators: name: University College Absalon
name: Danske Fysioterapeuter
First posted: 2020-09-16
Enrollment: 36
Sex: MALE
Minimum age (years): 18
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief 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.

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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
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)
timeFrame: Baseline-12 weeks.
Secondary outcomes:
measure: Single-Leg Decline Squat test
timeFrame: Baseline, 3, 6 weeks + 1 year follow-up
measure: Pain rating on Numeric Rating Scale (NRS; 0 = no pain; 10 = worst imaginable pain) during training.
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Self-reported activity level of sporting activities (hours/week)
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Doppler activity using Ultrasonography power Doppler
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Tendon thickness measured using Ultrasonography
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Muscle cross-sectional area measured using Ultrasonography
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Muscle structure measured by MRI
timeFrame: Baseline and 12 weeks
measure: Tendon dimensions measured by MRI
timeFrame: Baseline and 12 weeks
measure: Isometric Muscle Strength
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Pain Pressure Threshold
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
measure: Adverse events
timeFrame: Baseline-12 weeks + 1 year follow-up
measure: Victorian Institute of Sports Assessment - Patellar Tendinopathy
timeFrame: Baseline, 3, 6 and 12 weeks + 1 year follow-up
Other outcomes:
Locations:
city: Copenhagen
country: Denmark
facility: Department of Physical and Occupational Therapy / Institute of Sports Medicine Copenhagen, Bispebjerg Hospital
Study officials:
affiliation: Bispebjerg Hospital
name: Mikkel Holm Hjortshøj Jensen, MSc
role: PRINCIPAL_INVESTIGATOR
References: