The Hypoalgesic Effects of BFR Training in Nonspecific Shoulder Pain.

The Hypoalgesic Effects of BFR Training in Nonspecific Shoulder Pain. A Study Protocol of a Crossover Randomized Controlled Clinical Trial

The primary objective of the present study is to evaluate if a single acute BFR low load- exercise bout would reduce pain in patients with nonspecific shoulder pain and whether the potential hypoalgesia will be maintained after a 45-minute physical therapy shoulder exercise session. BFR exercise will be compared to a sham BFR exercise protocol. We hypothesize that the participants in the BFR group in will experience reduced pain and will be able to complete a scapula and rotator cuff muscles exercise loading program with reduced pain until the end of the exercise program.

Study Overview

• Status: Completed
• Conditions: Shoulder Pain; Shoulder Impingement; BFR
• Intervention / Treatment: Device: Blood flow restriction (BFR) with low load resistance training

Detailed Description

Shoulder pathologies are the 3rd most common musculoskeletal condition encountered by health professionals in their day-to-day clinical practice, followed by low back pain and neck pain. It is noteworthy that approximately 40%-54% of patients report ongoing pain lasting between 1-3 years , causing a huge economic burden both on the national health care system but also to the patients. The pathologies associated with development of shoulder pain are numerous, however, in recent years the research community dealing with musculoskeletal shoulder pain has emphasized the need to break free from diagnostic terminologies that refer to precise clinical diagnosis, since such a thig is nearly impossible to happen, due to the low validity and diagnostic accuracy of the special tests available to the clinician. In addition, the need to detach from diagnostic labels becomes even more intense if one takes into account the inability to correlate symptoms and clinical status with pathological findings in diagnostic tests. Nonspecific shoulder pain is an umbrella term that includes non-traumatic musculoskeletal disorders of the shoulder.

Therapeutic exercise is the mainstay of conservative treatment and appears to be a powerful tool in the hands of clinicians to improve pain, mobility, and function of the shoulder in individuals with nonspecific shoulder pain . There are several mechanisms that are hypothesized to explain the benefits of exercise in nonspecific shoulder pain. The neuromuscular mechanism is the most frequently mentioned and is commonly explained as strengthening of the rotator cuff inhibiting pain. Other mechanisms proposed are: tissue factors (e.g. tendon remodeling, blood flow improvement etc.), neuro-endocrine-immune (e.g. exercise induced hypoalgesia, central and peripheral nervous system adaptations etc) and physiological mechanisms (e.g. improvements in self-efficacy and coping with pain etc).

The BFR method is a type of training with parallel partial restriction of arterial inflow and complete venous outflow restriction in muscle tissue that is usually combined with parallel execution of low-load resistance exercises. Blood flow restriction is achieved by using special cuffs applied to both the upper and lower extremities. During the last decade the popularity of this technique seems to be growing rapidly due to its beneficial effects on increasing muscle strength and muscle hypertrophy in healthy adults and clinical population but also its acute hypoalgetic effect on healthy population by significantly increasing the patient pain thresholds. However, to date there is only one published study examining the acute hypoalgetic effects of BFR training in a clinical population, showing beneficial adaptations in reducing pain in people with patellofemoral pain

The primary objective of the present study is to evaluate if a single acute BFR low load- exercise bout would reduce pain in patients with nonspecific shoulder pain and whether the potential hypoalgesia will be maintained after a 45-minute physical therapy shoulder exercise session. BFR exercise will be compared to a sham BFR exercise protocol. We hypothesize that the participants in the BFR group in will experience reduced pain and will be able to complete a scapula and rotator cuff muscles exercise loading program with reduced pain until the end of the exercise program.

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Cyprus
  • Nicosia, Cyprus, 2404
    • European University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Adults presenting with nonspecific shoulder pain will be recruited using the following eligibility criteria:

Inclusion Criteria:

• Age >18≤40 years considering that the prevalence for degenerative rotator cuff tendinopathy increases from the age of 40 and above
• Shoulder pain intensity > 4/10 NPRS when performing active glenohumeral abduction and/or isometric resistance to glenohumeral external rotation from 0° of abduction.
• Duration of symptoms > 3 weeks (to avoid an inflammatory clinical picture).

Exclusion Criteria:

• Positive drop arm test (important indication for rotator cuff tear)
• Cervical radiculopathy having a positive specific spurling test or neurological symptoms in the upper limb
• Passive deficit in range of motion (ROM) > 2 levels of motion, where according to the literature it is an indication of frozen shoulder
• Body Mass Index (BMI) > 28
• Previous shoulder surgery
• Previous humerus fracture
• Cancer
• Rheumatic diseases
• Systemic pathologies (e.g. diabetes, rheumatism, fibromyalgia)
• History of previous neurological diseases
• History of thrombosis
• Cardiovascular pathologies
• Neurological diseases
• Long-term use of corticosteroids
• Injury or surgery < 1 month related to the shoulder girdle
• Hypertension (> 140/90mmHg)
• Anti-inflammatory treatment in the last 2 weeks
• Injectable therapy (last 3 months)
• Previous experience/knowledge of the BFR technique
• Inability to write and read Greek

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Blood flow restriction (BFR) with low load resistance training; A single BFR exercise (Biceps curl with dumbell) will be perform. The initial resistance load for performing the above exercise will correspond to 5% of the body weight of each participant (±0.250 kg). Participants will be asked to perform 4 sets of bicep curls. The first set will consist of repetitions until failure (inability to follow the rhythm or inability to perform an additional contraction) followed by 3 sets of 15 repetitions with 30 seconds rest between sets. In case that for any of the participants will not be able to complete all the repetitions, or they are unable to follow the pace of the metronome, the resistance load will be reduced by 0.5 kg. Vascular Occlusion Pressure will be set at 50-60% of the complete occlusion pressure for the intervention group .Five minutes after the execution of the biceps curl exercise, each participant will receive a specific training which will consist of six therapeutic exercises targeting in loading the rotator cuff and scapula muscles	Device: Blood flow restriction (BFR) with low load resistance training; Combination of low load resistance exercise in the upper limb with the addition of blood flow restriction or sham-blood flow restriction.
Placebo Comparator: Sham-Blood flow restriction (sham-BFR) with low load resistance training; Same procedure as experimental . The only difference between the two groups regarding the intervention will be the percentage of blood flow restriction cuff pressure. In the sham BFR group, as much pressure as 2 fingers can penetrate the cuff will be automatically applied via MADUP®, where based on the literature seems not to promote adaptations related to the use of the method.	Device: Blood flow restriction (BFR) with low load resistance training; Combination of low load resistance exercise in the upper limb with the addition of blood flow restriction or sham-blood flow restriction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	Baseline
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	15 minutes (1st session)
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	1 hour (1st session)
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	2nd session (> 72 hours after 1st session)
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	15 minutes (2nd session)
Pressure pain detection threshold assessment	PPDT's will assess using a hand-held mechanical pressure algometer in local and remote areas	1 hour (2nd session)
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	Baseline
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	15 minutes (1st session)
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	1 hour (1st session)
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	2nd session (> 72 hours after 1st session)
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	15 minutes (2nd session)
Maximal pain and strength in isometric shoulder external rotation	The MVIC of shoulder external rotation will be assessed using a hand held dynamometer. Additionally, the maximum value from 3 successful trials (no >15% difference between the 3 trials) will be used for statistical analysis. In addition, participants will be asked to rate their pain based on the NPRS scale (0-10) during the test.	1 hour (2nd session)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	Baseline (1st session)
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	15 minutes (1st session)
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	1 hour (1st session)
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	2nd session (> 72 hours after 1st session)
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	15 minutes (2nd session)
Pain during active shoulder Abduction	Pain during active shoulder abduction (0 to 180°) in standing in a NPRS scale	1 hour (2nd session)
Patient-perceived pain change	patient-perceived pain change using a global rating of change scale (GROC) based on a 7-point Likert scale ranging from "Much better - a very important improvement" to "Much worse - an important aggravation" (Jaeschke, 1986)	15 minutes (1st session)
Patient-perceived pain change	patient-perceived pain change using a global rating of change scale (GROC) based on a 7-point Likert scale ranging from "Much better - a very important improvement" to "Much worse - an important aggravation" (Jaeschke, 1986)	1 hour (1st session)
Patient-perceived pain change	patient-perceived pain change using a global rating of change scale (GROC) based on a 7-point Likert scale ranging from "Much better - a very important improvement" to "Much worse - an important aggravation" (Jaeschke, 1986)	2nd session (> 72 hours after 1st session)
Patient-perceived pain change	patient-perceived pain change using a global rating of change scale (GROC) based on a 7-point Likert scale ranging from "Much better - a very important improvement" to "Much worse - an important aggravation" (Jaeschke, 1986)	15 minutes (2nd session)
Patient-perceived pain change	patient-perceived pain change using a global rating of change scale (GROC) based on a 7-point Likert scale ranging from "Much better - a very important improvement" to "Much worse - an important aggravation" (Jaeschke, 1986)	1 hour (2nd session)
Shoulder Pain and Disability Index (SPADI) questionnaire	Shoulder Pain and Disability Index (SPADI) questionnaire which assesses the pain and difficulty experienced by the participant in daily activities of the upper extremity. The questionnaire is translated into Greek and cross-culturally weighted to the Greek population (Vrouva et al., 2016).	Baseline
Shoulder Pain and Disability Index (SPADI) questionnaire	Shoulder Pain and Disability Index (SPADI) questionnaire which assesses the pain and difficulty experienced by the participant in daily activities of the upper extremity. The questionnaire is translated into Greek and cross-culturally weighted to the Greek population (Vrouva et al., 2016).	2nd session (> 72 hours after 1st session)
Participant's rating of perceived exertion (RPE)	RPE using a modified Borg's scale (Borg CR10) immediately following the blood flow restriction or sham- blood flow restriction exercise session. The scale has been shown to be an valid alternate tool for estimating the exertion and intensity levels during resistance training (Brandt, 2013 ).	15 minutes (1st session)
Participant's rating of perceived exertion (RPE)	RPE using a modified Borg's scale (Borg CR10) immediately following the blood flow restriction or sham- blood flow restriction exercise session. The scale has been shown to be an valid alternate tool for estimating the exertion and intensity levels during resistance training (Brandt, 2013 ).	15 minutes (2nd session)

Collaborators and Investigators

• Sponsor: European University Cyprus

Study record dates

Study Major Dates

• Study Start (Actual): February 27, 2024
• Primary Completion (Actual): November 21, 2024
• Study Completion (Actual): November 21, 2024

Study Registration Dates

• First Submitted: July 6, 2023
• First Submitted That Met QC Criteria: July 13, 2023
• First Posted (Actual): July 21, 2023

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 16, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Keywords: Shoulder pain; BFR
• Additional Relevant MeSH Terms: Shoulder Injuries; Pain; Neurologic Manifestations; Musculoskeletal Diseases; Wounds and Injuries; Joint Diseases; Arthralgia; Shoulder Pain; Shoulder Impingement Syndrome
• Other Study ID Numbers: EUC

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No