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PainLIMITLESSNCT06621914

Is Low-load Resistance Training With Blood Flow Restriction Feasible During Rehabilitation of Military Personnel With Lower Limb Injuries? Phase One RCT.

A study testing BFR 80 and BFR40 in people with Pain and Persistent Pain, run by Defence Medical Rehabilitation Centre, UK at 1 site in United Kingdom.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

Pain can be one of the primary limiting factors to progress following musculoskeletal injury and may be caused by trauma or degenerative changes. There are few exercise rehabilitation interventions able to relieve pain, thereby reducing the number of military personnel fit for operations. Read more about this study

Who is it for?
Ages 18 to 55 years
Conditions the study is for
Pain, Persistent Pain, Musculoskeletal Pain
What is being tested?
BFR 80 and BFR40
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
28 participants
Where
1 siteUnited Kingdom
Study dates
28 Oct 2024to 30 Jun 2026
Phase
Interventional
Are there results?
Not yet: the study is under way

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 55 years
  • All sexes
  • No healthy volunteers
  • Adult

Who may be able to join

  • Serving UK military personnel,
  • Aged 18-55,
  • Has unilateral lower limb injury whereby pain is the primary limiting factor hindering progression, as diagnosed by relevant consultant and team,
  • Reduced occupational employability and function,
  • Scheduled to attend DMRC Stanford Hall for 3 week residential rehabilitation course.

Who cannot join

  • MSK-Specific Exclusion Criteria
  • Any medical contraindication related to BFR*
  • Non-musculoskeletal or serious pathological condition (i.e. Inflammatory arthropathy, infection or tumour)
  • Spinal or referred pain from non-local pain source
  • Any pre-diagnosed physical impairment or co-morbidities (including cardio-vascular disease) precluding the safe participation in the rehabilitation programme and/or assessment procedures
  • Corticosteroid or analgesic injection intervention to the affected area within the previous 7 days
Show all 19Show fewer
  • Currently pregnant, or have not yet completed a return to work assessment following the birth of your child.
  • Medical-Related Exclusion Criteria
  • History of cardiovascular disease (hypertension, peripheral vascular disease, thrombosis/embolism, ischaemic heart disease, myocardial infarction),
  • History of the following musculoskeletal disorders: rheumatoid arthritis, avascular necrosis or osteonecrosis, severe osteoarthritis
  • History of the following neurological disorders: Alzheimer's disease, amyotrophic lateral sclerosis, peripheral neuropathy, Parkinson's disease, severe traumatic brain injury,
  • Varicose veins in the lower limb,
  • Acute viral or bacterial upper or lower respiratory infection at screening,
  • Known or suspected lower limb chronic exertional compartment syndrome (CECS) (tourniquet raises intra-compartmental muscle pressure),
  • Surgical insertion of metal components at the position of cuff inflation,
  • History of any of the following conditions or disorders not previously listed: diabetes, active cancer,
  • History of elevated risk of unexplained fainting or dizzy spells during physical activity and/or exercise that causes loss of balance,
  • Increased risk of haemorrhagic stroke, exercise induced rhabdomyolysis,
  • Currently pregnant.

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United Kingdom1 site, 1 recruiting
  • Defence Medical Rehabilitation Centre, Stanford Hall

    Loughborough, Leicestershire, LE12 5QW

    Peter Ladlow, PhD, +44 1509 251 500 ext. ext 3407, peter.ladlow100@mod.gov.uk

    Peter Ladlow, PhD

    Recruiting

Other trials in United Kingdom

About this study

Official title: The Effects of Different Blood Flow Restriction Training Methodologies During the Rehabilitation of Military Personnel With Lower Limb Musculoskeletal Injuries Primarily Limited by Pain: a 2 Part Randomised Controlled Trial (Phase One)

Pain can be one of the primary limiting factors to progress following musculoskeletal injury and may be caused by trauma or degenerative changes. There are few exercise rehabilitation interventions able to relieve pain, thereby reducing the number of military personnel fit for operations. Low load blood flow restriction (BFR) exercise has been shown to elicit an analgesic response and promote beneficial physiological changes in a variety of clinical populations.

This two phase study, aims to:

Read more
  • Determine the most effective and feasible BFR resistance exercise protocol for reducing pain in UK military patients.
  • Determine the efficacy of an optimal BFR exercise protocol for reducing pain and improving rehabilitation outcomes in UK military patients.
  • Identify key physiological mechanisms underpinning any beneficial effect of BFR exercise on pain.

Consequently, results from this study will have direct clinical application and will aid best practice guidelines for the management of pain across Defence Rehabilitation by influencing the future rehabilitation paradigm. The investigators believe the results and impact will be far reaching, providing invaluable insight and knowledge to the clinical and scientific community to not only those embedded within Defence Rehabilitation, but also those working in civilian sector organisations and professional sport also.

Being tested
BFR 80, BFR40
Keywords
blood flow restriction, persistent pain, hypoalgesia
Medical subject headings
Pain, Musculoskeletal Pain

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • BFR 80Device

    Also called Blood flow restriction training, Occlusion training

    The intervention involves placing a pneumatic tourniquet system over the proximal thigh. The cuff is inflated to 80% of limb occlusion pressure during lower limb strengthening exercises. These exercises include leg press and knee extensor exercises. Four sets (30,15,15,15 repetitions) performed at 20% of one repetition maximum.

  • BFR40Device

    Also called Blood flow restriction training, Occlusion training

    The intervention involves placing a pneumatic tourniquet system over the proximal thigh. The cuff is inflated to 40% of limb occlusion pressure during lower limb strengthening exercises. These exercises include leg press and knee extensor exercises. Four sets (30,15,15,15 repetitions) performed at 20% of one repetition maximum.

Study groups in NCT06621914
Study groupRoleWhat they receive
BFR80ExperimentalLow load blood flow restriction training with high-pressure cuff (80% AOP) in addition to standard residential rehabilitation consisting of; (1) exercise-based therapy delivered in group settings and individually to address a variety of physical components relating to their pathology (e.g., balance and co-ordination, cardiovascular endurance, mobility and flexibility, motor control and dynamic stability, and muscular strength), (2) patient education sessions (e.g., activity modification, behavioural change, and focusing on pain management), and (3) one-on-one support sessions (e.g., dietetics, occupational therapy, physiotherapy, podiatry, prosthesis/orthosis specialists, social workers, and speech and language therapists).
Receives: Device: BFR 80
BFR40Active comparatorLow load blood flow restriction training with low-pressure cuff (40% AOP) in addition to standard residential rehabilitation consisting of; (1) exercise-based therapy delivered in group settings and individually to address a variety of physical components relating to their pathology (e.g., balance and co-ordination, cardiovascular endurance, mobility and flexibility, motor control and dynamic stability, and muscular strength), (2) patient education sessions (e.g., activity modification, behavioural change, and focusing on pain management), and (3) one-on-one support sessions (e.g., dietetics, occupational therapy, physiotherapy, podiatry, prosthesis/orthosis specialists, social workers, and speech and language therapists).
Receives: Device: BFR40

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Brief Pain Inventory

    The BPI is a patient administered, multi-dimensional, pain assessment tool commonly used within musculoskeletal clinical practice. Higher scores on the 9-item short form indicate greater interference with function, or greater pain intensity.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

Secondary outcomes (21)
  1. Pressure Pain Threshold Testing

    Pressure pain threshold assessment can help define regions of mechanical hypersensitivity, a common trait of central sensitisation. By utilising a digital pressure algometer (1cm^2 probe, Model FPX 50, Wagner Instruments, USA), the amount of pressure at which the sensation of pressure becomes unpleasant is deemed the PPT, with lower pressure values being indicative of central sensitisation.

    Measured: Pre-intervention (day 0), daily (before, immediately-post, and 1hr-post each BFR session; days 1-5), post-intervention (day 5) and at follow-up (day 8).

  2. Lower Extremity Function Scale

    The LEFS is a patient-reported outcome measure that measures functional status in patients with lower limb musculoskeletal injury. Ability to perform 20 activities, ranging from walking to running on uneven ground, are self-reported from 0-4 with higher scores indicating better function.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  3. Isometric Mid-Thigh Pull

    The isometric mid-thigh pull is a test that can assess multiple derivatives of maximal lower-limb muscle strength including, peak force, rate of force development and limb asymmetry. The participant is asked to stand on force plates (set within a mid-thigh pull rig) and then pull on the mid-thigh bar at maximal force.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  4. 5-RM Testing

    5-RM assessment on leg press and leg/knee extension machines (leg/knee extension pre-intervention only) to assess the participants strength, and inform % load for intervention period.

    Testing procedure: 5-minute cycling warm up, followed by 10-rep exercise specific warm up, and then successive attempts at performing a 5RM on injured limb only.

    The authors acknowledge that due to the likely interference effect of a pain response, performing a 'maximum effort' physical task in a lower limb injured cohort is unlikely to yield a true measure of MSK performance. It is more accurate to describe outcome scores as providing an 'indication' of participant performance and progression. We will highlight this as a potential weakness in our study but feel this is a challenge in the measurement of muscle force / strength in all MSK injury research. All outcomes measured will be implemented and recorded based upon a best effort at the time of assessment.

    Measured: Pre-intervention (day 0) and follow-up (day 8).

  5. Numerical Pain Rating Scale

    To assess the feasibility and tolerability of the BFR-RT interventions, a participant monitoring booklet will be used throughout the intervention period.

    The Numerical Pain Rating Scale (NPRS) for injury-specific pain and localised muscle soreness will be collected pre-intervention, immediately post-intervention, and 1-hour post-intervention for each BFR-RT session.

    Measured: Daily (before, immediately-post, and 1 hour-post each BFR session; days 1-5).

  6. Sessional Rate of Perceived Exertion

    To assess the feasibility and tolerability of the BFR-RT interventions, a participant monitoring booklet will be used throughout the intervention period.

    Sessional Rate of Perceived Exertion (scored 0-10; 0=no effort, 10=maximal effort) will be collected following each BFR-RT session.

    Measured: Daily (immediately post-intervention; day 1-5).

  7. Training Load

    To assess the feasibility and tolerability of the BFR-RT interventions, a participant monitoring booklet will be used throughout the intervention period.

    To quantify training load, the following calculation will be conducted following each BFR-RT session; sets x reps x load (kg).

    Specific Example:

    BFR-RT Leg Press at 25kg

    1 set x 30 reps + 3 sets x 15 reps = 75 reps 75 (reps) x 25 (kg) = 1875 (training load)

    Measured: Daily (immediately post-intervention; day 1-5).

  8. Copenhagen Hip and Groin Score

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Copenhagen Hip and Groin Score is a patient administered, multi-dimensional, pain assessment tool commonly used to assess symptomatic and functional burden associated with hip and groin pathology. Scored from 0-100, lower scores on the HAGOS represent greater symptomatic and functional burden. The MCID per domain is 8, 8, 9, 10, 11, and 12 points for hip-related QOL, symptoms, pain, sport and recreation activities, ADL, and participation in physical activities, respectively.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  9. Foot and Ankle Disability Index

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Foot and Ankle Disability Index is a 26-item ankle and foot specific, patient-reported, questionnaire which considers ADLs, function, pain and sleep. Each item is scored from 0 (unable to do/unbearable pain) to 4 (no difficulty at all/no pain), with a total point value reaching a maximum of 104; however, the PROM is scored as a percentage and a lower percentage indicates greater levels of disability and/or pain. To date, no MCID has been reported for the Foot and Ankle Disability outcome measure.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  10. Leeds Assessment of Neuropathic Symptoms and Signs

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Leeds Assessment of Neuropathic Symptoms and Signs is a self-reported questionnaire with a primary aim of distinguishing pain of a neuropathic origin, without the need for clinical assessment. The questionnaire consists of 7 questions, with a higher score suggesting the pain is predominantly of neuropathic origin. To date, no MCID has been reported for the Leeds Assessment of Neuropathic Symptoms and Signs.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  11. Non-Arthritic Hips Score

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Non-Arthritic Hips Score is a 20-item, self-reported, questionnaire covering four domains (activities, function, pain and symptoms), in patients without arthritic pathology. The summative score for Non-Arthritic Hips Score is between 0-100, with 100 representing a perfectly functioning hip. The MCID for this outcome measure is 8-points.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  12. Victorian Institute for Sport Assessment - Gluteal

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Victorian Institute for Sport Assessment - Glutealwas designed to evaluate the severity of disability in greater trochanteric pain syndrome populations. Formulated in the same manner as other Victorian Institute of Sport Assessment tendinopathy measures, the Victorian Institute for Sport Assessment - Gluteal is scored out of 100, with a greater score associated with greater function and less symptom impairment. There is currently no MCID reported within the literature for the Victorian Institute for Sport Assessment - Gluteal.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  13. Victorian Institute for Sport Assessment - Hamstring

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Victorian Institute for Sport Assessment - Hamstring was designed in the style of previous Victorian Institute of Sport Assessment tendinopathy outcome measures, but specifically to evaluate the severity of symptoms, function and ability to play sports in those with proximal hamstring tendinopathy. Scored out of 100, with higher scores being associated with greater function and less symptomatic impairments. A 4-point reduction was reported in the literature as being the threshold required to detect for true change when the standard error of measurement is considered; however, an MDIC of 22-points has been reported.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  14. Victorian Institute for Sport Assessment - Patella

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Victorian Institute for Sport Assessment - Patella is an 8 question, patient-reported measure developed specifically to subjectively assess the severity of symptoms, function and ability to play sports in those with patella tendinopathy . Scored out of 100, a greater score is associated with greater function and less symptom impairment, with 0 being the theoretical minimum score. The MCID for the Victorian Institute for Sport Assessment - Patella is 13-points.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  15. Daily Morning Wellbeing

    To assess the feasibility and tolerability of the BFR-RT interventions, a participant monitoring booklet will be used throughout the intervention period.

    Daily morning wellbeing questions (fatigue, muscle soreness, sleep quality, stress levels and mood) will be asked each morning on a Likert scale (1-5), before the first BFR-RT session.

    Measured: T2, Daily (before BFR session; days 1-5).

  16. Knee Injury and Osteoarthritis Outcome Score

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Knee Injury and Osteoarthritis Outcome Score is a five domain, patient-administered questionnaire, used to monitor disease course and outcomes following knee injury/OA or surgery. The five domains, ADL, knee-related QOL, other symptoms, pain, and sport and recreation function, are scored on a 0-100 scale, with a higher score indicating better function and less symptoms. The MCID for the Knee Injury and Osteoarthritis Outcome Score is 10-points for each domain.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  17. Victorian Institute for Sport Assessment - Achilles

    A single injury-specific outcome measure will also be collected at Day 0, Day 5 and Day 8.

    The Victorian Institute for Sport Assessment - Achilles is a patient-reported questionnaire designed to assess the severity of Achilles tendinopathy. With questions focused on the domains of function in ADLs, pain, and sporting activity, the questionnaire is scored out of 100 (100 = asymptomatic); however, a score less than 60 is often seen in Achilles tendinopathy populations. The MCID is set at 14-points for mid-portion Achilles tendinopathy, and 6.5 points for insertional tendinopathy.

    Measured: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).

  18. Musculoskeletal Health Questionnaire

    The MSK-HQ is a self-reported questionnaire that allows people with musculoskeletal conditions to report their symptoms and quality of life in a standardised way. This outcome measure is taken at baseline only (T0).

    Measured: T0, Pre-Admission (Day 0).

  19. Health Anxiety Depression Scale

    The Hospital Anxiety and Depression Scale (HADS) is a 14-item self-reported measure designed to assess anxiety and depression symptoms in medical patients, with emphasis on reducing the impact of physical illness on the total score. This outcome measure is taken at baseline only (T0).

    Measured: T0, Pre-Admission (Day 0).

  20. Demographics Questionnaire

    Personal and demographic characteristics including age, body height, body mass, body mass index, duration of symptoms, previous injuries, previous treatment, military occupation, duration of military service, smoking and drinking habits. This outcome measure is taken at baseline only (T0).

    Measured: T0, Pre-Admission (Day 0).

  21. Medication Record Sheet

    The medication record sheet is utilised to show what current medications each participant is using for their pathology. The drug name, drug purpose, dose size and frequency is noted. This outcome measure is taken at baseline only (T0).

    Measured: T0, Pre-Admission (Day 0).

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 Oct 2024
  2. Study start28 Oct 2024
  3. Primary completion29 May 2026 (estimated)
  4. Study completion30 Jun 2026 (estimated)

Resources

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
Model description
The overall study is a two phase RCT. Phase one will investigate two different BFR-RT protocols (high- vs low-pressure) for 1-week (7x BFR-RT sessions in 5 days). Phase two will take the BFR-RT protocol that elicited the greatest improvement in symptoms (high- or low-pressure) and compare that to conventional Uk Defence Rehabilitation practices over a 3 week period (21x BFR-RT sessions over 15 days).
Masking
None (open label)
Enrolment
28 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06621914
Sponsor's protocol ID
2318/MODREC/24a
Acronym
LIMITLESS
Status last verified
Nov 2024
First submitted
23 Sep 2024
Last updated
23 Apr 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: Upon reasonable request, grouped data (i.e., data that cannot individually identify participants) may be shared to other research groups for the advancement of research and clinical practices, by the chief investigator.

Publications

  • Gray L, Coppack RJ, Barker-Davies R, Cassidy RP, Bennett AN, Caplan N, Atkinson G, Bradshaw L, Chauhan J, Lunt KM, Hughes L, Ladlow P. Efficacy and acceptability of different blood flow restriction training interventions during the rehabilitation of military personnel with lower limb musculoskeletal injuries: protocol for a two-phase randomised controlled trial. BMJ Open. 2025 May 26;15(5):e096643. doi: 10.1136/bmjopen-2024-096643.

    PubMed 40425246

Questions about this trial

What is this clinical trial studying?

A study testing BFR 80 and BFR40 in people with Pain and Persistent Pain, run by Defence Medical Rehabilitation Centre, UK at 1 site in United Kingdom.

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 19 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: looking for participants now, as of the sponsor's last update on 23 Apr 2025. 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 United Kingdom. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Peter Ladlow, PhD (+44 1509 251 500 ext. ext 3407, peter.ladlow100@mod.gov.uk), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Brief Pain Inventory (time frame: Pre-intervention (day 0), post-intervention (day 5) and at follow-up (day 8).). 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 NCT06621914, 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 23 Apr 2025.

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