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:
* 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.
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,
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
Parallel
BFR 80
DeviceThe 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.
BFR40
DeviceThe 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.
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.
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.
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.
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.
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.
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Defence Medical Rehabilitation Centre, UK
Lead sponsor
University of Bath
Sponsor institution
Northumbria University
Collaborator
