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  • Journal article
    Greenberg N, Bull A, Wessely S, 2016,

    Chilcot: Physical and mental legacy of Iraq war on UK service personnel

    , BMJ, Vol: 354, ISSN: 0959-8138
  • Journal article
    Barnett-Vanes A, Sharrock A, Eftaxiopoulou T, Arora H, Macdonald W, Bull AM, Rankin SMet al., 2016,

    CD43Lo classical monocytes participate in the cellular immune response to isolated primary blast lung injury

    , Journal of Trauma and Acute Care Surgery, Vol: 81, Pages: 500-511, ISSN: 2163-0763

    BACKGROUND: Understanding of the cellular immune response to primary blast lung injury (PBLI) is limited, with only the neutrophil response well documented. Moreover, its impact on the immune response in distal organs remains poorly understood. In this study, a rodent model of isolated primary blast injury was used to investigate the acute cellular immune response to isolated PBLI in the circulation and lung; including the monocyte response, and investigate distal sub-acute immune effects in the spleen and liver 6hr after injury. METHODS: Rats were subjected to a shock wave (~135kPa overpressure, 2ms duration) inducing PBLI or sham procedure. Rat physiology was monitored and at 1, 3 and 6 hr thereafter blood, lung, and Broncho-alveolar lavage fluid (BALF) were collected and analysed by flow cytometry (FCM), ELISA and Histology. In addition, at 6hr spleen and liver were collected and analysed by FCM. RESULTS: Lung histology confirmed pulmonary barotrauma and inflammation. This was associated with rises in CXCL-1, IL-6, TNF-α and albumin protein in the BALF. Significant acute increases in blood and lung neutrophils and CD43Lo/His48Hi (classical) monocytes/macrophages were detected. No significant changes were seen in blood or lung 'non-classical' monocyte, NK, B or T Cells. In the BALF, significant increases were seen in neutrophils, CD43Lo monocyte-macrophages and MCP-1. Significant increases in CD43Lo and Hi monocyte-macrophages were detected in the spleen at 6hr. CONCLUSIONS: This study reveals a robust and selective response of CD43Lo/His48Hi (classical) monocytes - in addition to neutrophils - in blood and lung tissue following PBLI. An increase in monocyte-macrophages was also observed in the spleen at 6hr. This profile of immune cells in the blood and BALF could present a new research tool for translational studies seeking to monitor, assess or attenuate the immune response in blast injured patients. EVIDENCE: Experimental laboratory study.WC- 300.

  • Journal article
    Buckeridge EM, Weinert-Aplin RA, Bull AM, McGregor AHet al., 2016,

    Influence of foot-stretcher height on rowing technique and performance

    , Sports Biomechanics, Vol: 15, ISSN: 1752-6116

    Strength, technique, and coordination are crucial to rowing performance, but external interventions such as foot-stretcher set-up can fine-tune technique and optimise power output. For the same resultant force, raising the height of foot-stretchers on a rowing ergometer theoretically alters the orientation of the resultant force vector in favour of the horizontal component. This study modified foot-stretcher heights and examined their instantaneous effect on foot forces and rowing technique. Ten male participants rowed at four foot-stretcher heights on an ergometer that measured handle force, stroke length, and vertical and horizontal foot forces. Rowers were instrumented with motion sensors to measure ankle, knee, hip, and lumbar–pelvic kinematics. Key resultant effects of increased foot-stretcher heights included progressive reductions in horizontal foot force, stroke length, and pelvis range of motion. Raising foot-stretcher height did not increase the horizontal component of foot force as previously speculated. The reduced ability to anteriorly rotate the pelvis at the front of the stroke may be a key obstacle in gaining benefits from raised foot-stretcher heights. This study shows that small changes in athlete set-up can influence ergometer rowing technique, and rowers must individually fine-tune their foot-stretcher height to optimise power transfer through the rowing stroke on an ergometer.

  • Journal article
    Bull AMJ, Eftaxiopoulou T, Persad L, 2016,

    Assessment of Performance Parameters of a Series of Five ‘Historical’ Cricket Bat Designs

    , Proceedings of the Institution of Mechanical Engineers, Part P: Journal of Sports Engineering and Technology, Vol: 231, Pages: 57-62, ISSN: 1754-3371

    The performance of five different bat designs, from different eras spanning from 1905 to 2013, was assessed to addressthe question whether the changes in bat design over the years have resulted in a performance advantage to the batsman.Moment of inertia and ‘freely suspended’ vibration analysis tests were conducted, as these physical properties have beendirectly associated with rebound characteristics of the bats. Results showed that changes in the blade’s profile such asdistribution of the blade’s weight along the edges and closer to the toe have resulted in a clear performance advantageof the newest bats in comparison with older designs. These results add to the weight of evidence in cricket that thegame has changed to the benefit of the batsman and additional changes to bat design are conceivable as modern engineeringtools are applied to further optimise performance.

  • Journal article
    Amabile C, Bull A, Kedgley A, 2016,

    The centre of rotation of the shoulder complex and the effect of normalisation

    , Journal of Biomechanics, Vol: 49, Pages: 1938-1943, ISSN: 1873-2380

    Shoulder motions consist of a composite movement of three joints and one pseudo-joint, which together dictate the humerothoracic motion. The purpose of this work was to quantify the location of the centre of rotation (CoR) of the shoulder complex as a whole. Dynamic motion of 12 participants was recorded using optical motion tracking during coronal, scapular and sagittal plane elevation. The instantaneous CoR was found for each angle of elevation using helical axes projected onto the three planes of motion. The location of an average CoR for each plane was evaluated using digitised and anthropometric measures for normalisation. When conducting motion in the coronal, scapular, and sagittal planes respectively, the coefficients for locating the CoRs of the shoulder complex are −61%, −61%, and −65% of the anterior-posterior dimension – the vector between the midpoint of the incisura jugularis and the xiphoid process and the midpoint of the seventh cervical vertebra and the eighth thoracic vertebra; 0%, −1%, and −2% of the superior-inferior dimension – the vector between the midpoint of the acromioclavicular joints and the midpoint of the anterior superior iliac spines; and 57%, 57%, and 78% of the medial-lateral dimension −0.129 times the height of the participant. Knowing the location of the CoR of the shoulder complex as a whole enables improved participant positioning for evaluation and rehabilitation activities that involve movement of the hand with a fixed radius, such as those that employ isokinetic dynamometers.

  • Book chapter
    Campos-Pires R, Dickinson R, 2016,

    Modelling Blast Brain Injury

    , Blast Injury Science and Engineering A Guide for Clinicians and Researchers, Editors: Clasper, Bull, Mahoney, Publisher: Springer, Pages: 173-182, ISBN: 9783319218670

    The consequences of blast traumatic brain injury (blast-TBI) in humans are largely determined by the characteristics of the trauma insult and, within certain limits, the individual responses to the lesions inflicted (1). In blast-TBI the mechanisms of brain vulnerability to the detonation of an explosive device are not entirely understood. They most likely result from a combination of the different physical aspects of the blast phenomenon, specifically extreme pressure oscillations (blast-overpressure wave), projectile penetrating fragments and acceleration-deceleration forces, creating a spectrum of brain injury that ranges from mild to severe blast-TBI (2). The pathophysiology of penetrating and inertially-driven blast-TBI has been extensively investigated for many years. However, the brain damage caused by blast-overpressure is much less understood and is unique to this type of TBI (3). Indeed, there continues to be debate about how the pressure wave is transmitted and reflected through the brain and how it causes cellular damage (4). No single model can mimic the clinical and mechanical complexity resulting from a real life blast-TBI (3). The different models, non-biological (in silico or surrogate physical) and biological (ex vivo, in vitro or in vivo), tend to complement each other.

  • Book chapter
    Newell N, Masouros SD, 2016,

    Testing and development of mitigation systems for tertiary blast

    , Blast Injury Science and Engineering A Guide for Clinicians and Researchers, Editors: Bull, Clasper, Mahoney, Publisher: Springer, Pages: 249-255, ISBN: 9783319218670

    Biomechanics in blast is a key discipline in blast injury science and engineering that addresses the consequences of high forces, large deformations and extreme failure and thus relates closely to knowledge of materials science (Chap. 3) and ...

  • Journal article
    Newell N, Salzar R, Bull AMJ, Masouros SDet al., 2016,

    A validated numerical model of a lower limb surrogate to investigate injuries caused by under-vehicle explosions

    , Journal of Biomechanics, Vol: 49, Pages: 710-717, ISSN: 0021-9290

    Under-vehicle explosions often result in injury of occupants׳ lower extremities. The majority of these injuries are associated with poor outcomes. The protective ability of vehicles against explosions is assessed with Anthropometric Test Devices (ATDs) such as the MIL-Lx, which is designed to behave in a similar way to the human lower extremity when subjected to axial loading. It incorporates tibia load cells, the response of which can provide an indication of the risk of injury to the lower extremity through the use of injury risk curves developed from cadaveric experiments. In this study an axisymmetric finite element model of the MIL-Lx with a combat boot was developed and validated. Model geometry was obtained from measurements taken using digital callipers and rulers from the MIL-Lx, and using CT images for the combat boot. Appropriate experimental methods were used to obtain material properties. These included dynamic, uniaxial compression tests, quasi-static stress-relaxation tests and 3 point bending tests. The model was validated by comparing force-time response measured at the tibia load cells and the amount of compliant element compression obtained experimentally and computationally using two blast-injury experimental rigs. Good correlations between the numerical and experimental results were obtained with both. This model can now be used as a virtual test-bed of mitigation designs and in surrogate device development.

  • Journal article
    Eftaxiopoulou T, Barnett-Vanes A, Arora H, Macdonald W, Nguyen TTN, Itadani M, Sharrock AE, Britzman D, Proud WG, Bull AMJ, Rankin SMet al., 2016,

    Prolonged but not short duration blast waves elicit acute inflammation in a rodent model of primary blast limb trauma

    , Injury, Vol: 47, Pages: 625-632, ISSN: 0020-1383

    BackgroundBlast injuries from conventional and improvised explosive devices account for 75% of injuries from current conflicts; of these over 70% involve the limbs. Variable duration and magnitude of blast wave loading occurs in real-life explosions and is hypothesised to cause different injuries. While a number of in-vivo models report the inflammatory response to blast injuries, the extent of this response has not been investigated with respect to the duration of the primary blast wave. The relevance is that explosions in open air are of short duration compared to those in confined spaces. MethodsHind limbs of adult Sprauge-Dawley rats were subjected to focal isolated primary blast waves of varying overpressure (1.8-3.65kPa) and duration (3.0-11.5ms), utilising a shock tube and purpose built experimental rig. Rats were monitored during and after blast. At 6 and 24hrs after exposure blood, lungs, liver and muscle tissue were collected and prepared for histology and flow cytometry.ResultsAt 6hrs increases in circulating neutrophils and CD43Lo/His48Hi monocytes were observed in rats subjected to longer duration blast waves. This was accompanied by increases in circulating pro-inflammatory chemo/cytokines KC and IL-6. No changes were observed with shorter duration blast waves irrespective of overpressure. In all cases, no histological damage was observed in muscle, lung or liver. By 24hrs post-blast all inflammatory parameters had normalised. ConclusionsWe report the development of a rodent model of primary blast limb trauma that is the first to highlight an important role played by blast wave duration and magnitude in initiating acute inflammatory response following limb injury in the absence of limb fracture or penetrating trauma. The combined biological and mechanical method developed can be used to further understand the complex effects of blast waves in a range of different tissues and organs in-vivo.

  • Book
    Southgate DFL, Childs PRN, Bull AMJ, 2016,

    Sports Innovation, Technology and Research

    , Publisher: World Scientific, ISBN: 9781786340412

    Sports Innovation, Technology and Research gives an insight into recent research and design projects at Imperial College London. It presents the on-going development of a diverse range of areas from elite rowing performance to impact protection to sporting amenities in communities.Also included are descriptions of some of the latest innovations that have been developed as part of the Rio Tinto Sports Innovation Challenge, an initiative that tasked engineering students to design, build and implement Paralympic and other sporting equipment. It offers a glimpse at the breadth of creativity that can be achieved when human centred design is applied to an area such as disabled sport. It also shows the potential that design and engineering have to contribute to healthy lifestyles and the generation of whole new sporting domains.

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