Anthony M J Bull

Imperial College London | Imperial · Department of Bioengineering

The stretch reflex is a fundamental component of the motor system that orchestrates the coordinated muscle contractions underlying movement. At the heart of this process lie the muscle spindles (MS), specialized receptors finely attuned to fluctuations in tension within intrafusal muscle fibres. The tension variation in the MS triggers a series of...

Background Direct skeletal fixation, a surgical technique enabling the attachment of an external prosthesis directly to the bone through a percutaneous implant, offers an enticing solution for patients with lower limb amputations facing socket-related issues. However, understanding of its impact on musculoskeletal function remains limited. Methods...

Bone has the capability to adapt its density in response to mechanical stimuli through a process known as bone remodeling, which has been simulated in silico using various algorithms in several studies, with Strain Energy Density (SED) being a commonly used driving parameter. A spatial influence function has been introduced in addition to the remod...

Aims The survival of humeral hemiarthroplasties in patients with relatively intact glenoid cartilage could theoretically be extended by minimizing the associated postoperative glenoid erosion. Ceramic has gained attention as an alternative to metal as a material for hemiarthroplasties because of its superior tribological properties. The aim of this...

Introduction Rehabilitation after childhood lower limb loss is complex and dependent on multiple stakeholders and environmental factors. While research with adults underscores the importance of involving prosthetic limb users and caregivers in discussions to drive innovation, children are often excluded or not effectively engaged. This protocol lay...

Background Traumatic brain injury (TBI) is common in military campaigns and is a risk factor for dementia. A rme D Ser V ices Tr A uma and Rehabilitatio N Out C om E -TBI (ADVANCE-TBI) aims to ascertain neurological outcomes in UK military personnel with major battlefield trauma, leveraging advances in quantification of axonal breakdown markers lik...

Individuals with transfemoral lower limb amputations walk with adapted gait. These kinetic and kinematic compensatory strategies will manifest as differences in muscle recruitment patterns. It is important to characterize these differences to understand the reduced endurance, reduced functionality, and progression of co-morbidities in this populati...

Objective To elicit expert opinion and gain consensus on specific exercise intervention parameters to minimise hip bone mineral density (BMD) loss following traumatic lower limb amputation. Methods In three Delphi rounds, statements were presented to a panel of 13 experts from six countries. Experts were identified through publications or clinical...

Background Heart rate variability (HRV) is a marker of autonomic function. However, the reliability of short‐term HRV measurement in individuals with combat‐related traumatic injury (CRTI) remains undetermined. Methods An intra‐ and inter‐rater reliability study was conducted using a subsample (n = 35) of British servicemen with CRTI enrolled in t...

Osteoarthritis (OA) is a common chronic disease largely driven by mechanical factors, causing significant health and economic burdens worldwide. Early detection is challenging, making animal models a key tool for studying its onset and mechanically-relevant pathogenesis. This review evaluate current use of preclinical in vivo models and progressive...

Various non-electrocardiogram (ECG) based methods are considered reliable sources of heart rate variability (HRV) measurement. However, the ultra-short recording of a femoral arterial waveform has never been validated against the gold-standard ECG-based 300s HRV and was the aim of this study. A validity study was conducted using a sample from the f...

Objective Upper limb (UL) disability in people with UL amputation/s is well reported in the literature, less so for people with lower limb amputation/s. This study aimed to compare UL disability in injured (major trauma) and uninjured UK military personnel, with particular focus on people with upper and lower limb amputation/s. Methods A volunteer...

Background Respiration is a crucial determinant of autonomic balance and heart rate variability (HRV). The comparative effect of spontaneous versus paced breathing on HRV has been almost exclusively explored in healthy adults and never been investigated in an injured military cohort. Objective To examine the effect of spontaneous versus paced brea...

Background Currently, there is little available in-depth analysis of the biomechanical effect of different prostheses on the musculoskeletal system function and residual limb internal loading for persons with bilateral transfemoral/through-knee amputations (BTF). Commercially available prostheses for BTF include full-length articulated prostheses (...

B ackground This study investigated the relationship between combat-related traumatic injury (CRTI) and its severity and predicted cardiovascular disease (CVD) risk. Material and methods This was an analysis of comparative 10-year predicted CVD risk (myocardial infarction, stroke or CVD-death) using the QRISK®3 scoring-system among adults recruite...

Abstract Introduction Lower limb amputation results in reduced bone mineral density (BMD) on the amputated side. Exercise interventions have proven effective in improving BMD. However, such interventions have not been attempted in an amputee population. Exercises designed for people with intact limbs may not be suitable for amputees, due to joint l...

Introduction: Combat-related traumatic injury (CRTI) adversely affects heart rate variability (HRV). The mediating effect of mental and physical health factors on the relationship between CRTI, its severity and HRV has not been previously studied and investigated. Materials and methods: A cross-sectional mediation analysis of the ArmeD SerVices...

Background Combat-related traumatic injury (CRTI) has been linked to an increased cardiovascular disease (CVD) risk in servicemen returning from military operations. While Heart Rate Variability (HRV) has been established as an objective and non-invasive marker of CVD risk, the long-term impact of unselected CRTI on HRV has not been explored to dat...

Most cases of unilateral knee osteoarthritis (OA) progress to bilateral OA within 10 years. Biomechanical asymmetries have been implicated in contralateral OA development; however, gait analysis alone does not consistently detect asymmetries in OA patient gait. Stair ambulation is a more demanding activity that may be more suited to reveal between-...

Background: The relationship between acute combat-related traumatic injury (CRTI) to coronary flow reserve (CFR) and subclinical cardiovascular risk have not been examined and was the primary aim of this study. Methods and results: UK combat veterans from the ADVANCE cohort study (UK-Afghanistan War 2003-14) with traumatic limb amputations were...

The association between combat-related traumatic injury (CRTI) and bone health is uncertain. A disproportionate number of lower limb amputees from the Iraq and Afghanistan conflicts are diagnosed with osteopenia/osteoporosis, increasing lifetime risk of fragility fracture and challenging traditional osteoporosis treatment paradigms. The aim of this...

Purpose: A low-cost modular external fixator for the lower limb has been developed for global surgery use. The purpose of this study is to assess outcome measures in the first clinical use of the device. Methods: A prospective cohort study was conducted with patients recruited in two trauma hospitals. Initial clinical procedure data were collect...

Introduction: Due to loss in musculoskeletal capacity, there is an increased burden on the residual limbs of bilateral transfemoral and through-knee persons with limb loss. This reduced capacity is associated with an increased cost of walking that is detrimental to functionality. Compensatory gait strategies are adopted by this population. However,...

Major trauma is a condition that can result in severe bone damage. Customised orthopaedic reconstruction allows for limb salvage surgery and helps to restore joint alignment. For the best possible outcome three dimensional (3D) medical imaging is necessary, but its availability and access, especially in developing countries, can be challenging. In...

Introduction Outcomes of traumatic brain injury (TBI) are highly variable, with cognitive and psychiatric problems often present in survivors, including an increased dementia risk in the long term. Military personnel are at an increased occupational risk of TBI, with high rates of complex polytrauma including TBI characterising the UK campaign in A...

Amputation imposes significant challenges in locomotion to millions of people with limb loss worldwide. The decline in the use of the residual limb results in muscle atrophy that affects musculoskeletal dynamics in daily activities. The aim of this study was to quantify the lower limb muscle volume discrepancy based on magnetic resonance (MR) imagi...

A finite-element (FE) model, previously validated for underbody blast (UBB) loading, was used here to study the effect of stature and of mitigation systems on injury risk to the leg. A range of potential UBB loadings was simulated. The risk of injury to the leg was calculated when no protection was present, when a combat boot (Meindl Desert Fox) wa...

Background: This systematic review aims to ascertain how accurately 3D models can be predicted from two-dimensional (2D) imaging utilising statistical shape modelling. Methods: A systematic search of published literature was conducted in September 2022. All papers which assessed the accuracy of 3D models predicted from 2D imaging utilising stati...

This section presents the engineering tools that we currently have at our disposal when investigating blast injury science and engineering and notes the challenges that are yet to be addressed. This short overview describes the various areas that are addressed within the chapters of this section.KeywordsPhysical modellingComputational modellingEqui...

This chapter considers the forensic investigation of explosions with three sections each outlining methods to assist the Court.In Sect. 10.1, we describe the immediate aftermath and evidence collection indicating how clinical staff caring for victims may help or hinder this process. Thereafter follow two case studies of expert panel review.Section...

Computational modelling of how ectopic bone forms following blast injury can predict both the location and severity of the aberrant bone. As a loading-mediated process, this modelling uses the principle of Wolff’s Law combined with mechanobiological theory to investigate the effect of loading during treatment and rehabilitation. Small changes to th...

Heterotopic ossification (HO) is the process of de novo bone formation in non-osseous tissues and is common following blast-induced traumatic amputations. Inflammatory cytokines as well as mechanical loading play a key role in the initiation and the progression of the disease and therefore the downstream biomarkers under specific signal transductio...

Treating open fractures in long bones can be challenging and if not performed properly can lead to poor outcomes such as mal/non-union, deformity, and amputation. One of the most common methods of treating these fracture types is temporary external fixation followed by definitive fixation. The shortage of high-quality affordable external fixators i...

Major trauma is a condition that can result in severe bone damage. Customised orthopaedic reconstruction allows for limb salvage surgery and helps to restore joint alignment. For the best possible outcome three dimensional (3D) medical imaging is necessary, but its availability and access, especially in developing countries, can be challenging. In...

Background Surgeons remain hesitant to perform biceps tenodesis in athletes with type II superior labrum anterior-to-posterior tears due to the lack of reported clinical outcomes for individual overhead throwing sports and associated concerns that this may predispose the joint to instability. This study aimed to assess the effect of biceps tenodesi...

Functional motor redundancy enables humans to move with distinct muscle activation patterns while achieving a similar outcome. Since humans select similar strategies, there seems to be an optimal control. However, older adults move differently to young adults. The question is whether this is this due to an altered reinforcement scheme, altered sens...

Background Post-traumatic growth (PTG) is a positive psychological consequence of trauma. The aims of this study were to investigate whether combat injury was associated with deployment-related PTG in a cohort of UK military personnel who were deployed to Afghanistan, and whether post-traumatic stress disorder (PTSD), depression and pain mediate th...

Background: The long-term psychosocial outcomes of UK armed forces personnel who sustained serious combat injuries during deployment to Afghanistan are largely unknown. We aimed to assess rates of probable post-traumatic stress disorder (PTSD), depression, anxiety, and mental health-associated multimorbidity in a representative sample of serving a...

Electromagnetic (EM) tracking has been used to quantify biomechanical parameters of the lower limb and lumbar spine during ergometer rowing to improve performance and reduce injury. Optical motion capture (OMC) is potentially better suited to measure comprehensive whole-body dynamics in rowing. This study compared accuracy and precision of EM and O...

Objective The association between combat-related traumatic injury (CRTI) and cardiovascular risk is uncertain. This study aimed to investigate the association between CRTI and both metabolic syndrome (MetS) and arterial stiffness. Methods This was a prospective observational cohort study consisting of 579 male adult UK combat veterans (UK-Afghanis...

Introduction: The relationship between combat-related traumatic injury (CRTI) and cardiovascular risk is uncertain. Available data are largely derived from small retrospective or cross sectional studies. Hypothesis: This study was designed to investigate, prospectively, the link between CRTI and both metabolic syndrome (MetS) and arterial stiffness...

Osteoarthritis (OA) is a global health issue with myriad pathophysiological factors and is one of the most common causes of chronic disability in adults due to pain and altered joint function. The end stage of OA develops from a destructive inflammatory cycle, driven by the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumour necrosis facto...

Amputation of a major limb, and the subsequent return to movement with a prosthesis, requires the development of compensatory strategies to account for the loss. Such strategies, over time, lead to regional muscle atrophy and hypertrophy through chronic under or overuse of muscles compared to uninjured individuals. The aim of this study was to quan...

Improvised explosive devices (IEDs) used in the battlefield cause damage to vehicles and their occupants. The injury burden to the casualties is significant. The biofidelity and practicality of current methods for assessing current protection to reduce the injury severity is limited. In this study, a finite-element (FE) model of the leg was develop...

Rehabilitation is an important treatment for non‐insertional Achilles tendinopathy. To date, eccentric loading exercises (ECC) have been the predominant choice; however, mechanical evidence underlying their use remains unclear. Other protocols, such as heavy slow resistance loading (HSR), have shown comparable outcomes, but with less training time....

The cyamella is a rare, generally asymptomatic, knee sesamoid bone located in the proximal tendon of the popliteal muscle. Only two studies have investigated cyamella presence/absence in humans, putting ossified prevalence rates at 0.57%–1.8%. We aim to (a) determine cyamella prevalence in a Korean population, (b) examine coincident development of...

Objective: Customisation of musculoskeletal modelling using magnetic resonance imaging (MRI) significantly improves the model accuracy, but the process is time consuming and computationally intensive. This study hypothesizes that linear scaling to a lower limb amputee model with anthropometric similarity can accurately predict muscle and joint rea...

Capacity is the physiological ability of the neuromusculoskeletal systems; this declines with age. This decline in capacity may result in the inability to stand up (sit-to-stand, sit-to-walk), which is an important movement for independent living. Compensation, as a result of functional redundancy, is key in understanding how much age-related decli...

The prevention, mitigation and treatment of movement impairments, ideally, requires early diagnosis or identification. As the human movement system has physiological and functional redundancy, movement limitations do not promptly arise at the onset of physical decline. A such, prediction of movement limitations is complex: it is unclear how much de...

Goodwin, JE and Bull, AMJ. Novel assessment of isometric hip extensor function: reliability, joint angle sensitivity, and concurrent validity. J Strength Cond Res XX(X): 000-000, 2021-Closed-chain hip extension function has not been well examined. The aim of this study was to examine the reliability, joint angle sensitivity, muscle recruitment, and...

Aim In recent conflicts, most injuries to the extremities are due to blast resulting in a large number of lower limb amputations. These lead to heterotopic ossification (HO), phantom limb pain (PLP), and functional deficit. The mechanism of blast loading produces a combined facture and amputation. Therefore, to study these conditions, in vivo model...

Background Musculoskeletal modelling is a common means by which to non-invasively analyse movement. Such models have largely been used to observe function in both healthy and patient populations. However, utility in a clinical environment is largely unknown. The aim of this review was to explore existing uses of musculoskeletal models as a clinical...

Heterotopic ossification (HO) is the process of de novo bone formation in non-osseous tissues. HO can occur following trauma and burns and over 60% of military personnel with blast-associated amputations develop HO. This rate is far higher than in other trauma-induced HO development. This suggests that the blast effect itself is a major contributin...

Introduction The Afghanistan war (2003–2014) was a unique period in military medicine. Many service personnel survived injuries of a severity that would have been fatal at any other time in history; the long-term health outcomes of such injuries are unknown. The A rme D Ser V ices Tr A uma and Rehabilitatio N Out C om E (ADVANCE) study aims to dete...

Heavily loaded overhead training tasks, such as pull‐ups are an effective strength training and rehabilitation exercise requiring high muscle forces maintained over a large range of motion. This study used experiments and computational modelling to examine loading patterns during three different pull‐up variants and highlighted risks to vulnerable...

Background The critical shoulder angle (CSA) has been shown to be correlated with shoulder disease states. The biomechanical hypothesis to explain this correlation is that the CSA changes the shear and compressive forces on the shoulder. The objective of this study is to test this hypothesis by use of a validated computational shoulder model. Speci...

High functioning military transtibial amputees (TTAs)with well‐fitted state of the art prosthetics have gait that is indistinguishable from healthy individuals, yet they are more likely to develop knee osteoarthritis (OA)of their intact limbs. This contrasts with the information at the knees of the amputated limbs that has been shown to be at a sig...

Shortcomings in capabilities of below-knee (transtibial) prostheses, compared to their biological counterparts, still cause medical complications and functional deficit to millions of amputees around the world. Although active (powered actuation) transtibial prostheses have the potential to bridge these gaps, the current control solutions limit the...

Background: Bone shapes strongly influence force and moment predictions of kinematic and musculoskeletal models used in motion analysis. The precise determination of joint reference frames is essential for accurate predictions. Since clinical motion analysis typically does not include medical imaging, from which bone shapes may be obtained, scalin...

In healthy ageing, capacity declines in the neural, muscular, and skeletal systems, and each system decline has its effect on the execution of complex motor tasks. This decline in capacity can result in the inability to stand up (sit-to-stand, sit-to-walk), which is a key movement for independence. The mechanisms leading to mobility limitations or...

To prevent, mitigate and treat movement impairments, we need to recognize early signs of decline and understand how to best compensate for limitations. The mechanisms leading to movement impairments are complex, overlapping, and interdependent and the fields of biomechanics, motor control, and physiology must be combined to understand these mechani...

Introduction Un Critical Shoulder Angle (CSA) anormal a été identifié comme un élément participant à la survenue de pathologies comme les lésions de la coiffe des rotateurs (CSA important) ou l’omarthrose (CSA faible) dans de multiples études cliniques. Les hypothèses biomécaniques pour expliquer ces phénomènes sont qu’une modification du CSA entra...

Changes in movement pattern in low back pain (LBP) groups have been analysed by reporting predefined discrete variables. However, this approach does not consider the full kinematic data waveform and its dynamic information, potentially exposing the analysis to bias. Statistical Parametric Mapping (SPM) has been introduced and applied to 1 dimension...

Available open access here https://onlinelibrary.wiley.com/doi/full/10.1111/joa.13091 The fabella is a sesamoid bone located in the gastrocnemius behind the lateral femoral condyle. In humans, fabellae are 3.5 times more common today than they were 100 years ago, with prevalence rates varying between and within populations. In particular, fabella...

The ability to measure full six degrees-of-freedom knee joint kinematics is critical in the diagnosis of knee pathology. Soft tissue artifact (STA) remains the greatest source of error in measurement knee kinematics. The purpose of this study is to present a new femoral clamp to reduce STA at the thigh while preserving the natural gait pattern. Kne...

The ageing population has led to recent increases in musculoskeletal conditions, with muscle weakness a major contributor to functional decline. Understanding the early phases of muscle weakness will help devise treatments to extend musculoskeletal health. Little is understood of the effects of muscle weakness on everyday activities such as sit-to-...

By 2050 the proportion of over 65s is predicted to be 20% of the population. The consequences of an age-related reduction in muscle mass have not been fully investigated and, therefore, the aim of the present study was to quantify the muscle and joint contact forces using musculoskeletal modelling, during a sit-to-stand activity, to better explain...

Background and significance Blast injuries arising from high explosive weaponry is common in conflict areas. While blast injury characteristics are well recognised in the adults, there is a lack of consensus as to whether these characteristics translate to the paediatric population. Understanding blast injury patterns in this cohort is essential fo...

The aim of this poster (full article pending) is to introduce a general framework to describe mechanisms of movement limitations providing definitions of neuromusculoskeletal capacity, reserve, movement objectives, and compensation (CaReMoOC from now on). The framework can be generally applied to a variety of pathologies, patient or subject groups,...

In comparison to through knee amputees the outcomes for above‐the‐knee amputees are relatively poor; based on this novel techniques have been developed. Most current percutaneous implant based solutions for transfemoral amputees make use of high stiffness intramedullary rods for skeletal fixation which can have risks including infection, femoral fr...