Military training-related abdominal injuries and diseases: Common types, prevention and treatment.

Military training is intense, difficult and often dangerous, so all kinds of injuries or diseases frequently occur during training. Most of the previous studies and reviews on military training-related injuries focused on musculoskeletal system, whereas there are no reviews of abdominal injuries and diseases. Although the incidence of military training-related abdominal injuries and diseases is relatively low, the patients' condition is often critical especially in the presence of abdominal organ injury, leading to multi-organ dysfunction syndrome and even death. This paper elaborates on common types of military training-related abdominal injuries and diseases as well as the prevention and treatment measures, which provides some basis for scientific and reasonable training and improvement of medical security.

Transcholecystic Contrast-Enhanced Ultrasound-Guided Percutaneous Transhepatic Biliary Drainage for Central Bile Duct Protection During Thermal Tumor Ablation.

Intraductal cooling via a percutaneous transhepatic biliary drainage tube holds great promise in facilitating thermal ablation of liver tumors adjacent to the central bile ducts. However, the difficulties and complications associated with puncturing nondilated bile ducts are greater than those associated with puncturing dilated bile ducts. As reported here, percutaneous transcholecystic contrast-enhanced ultrasound was performed in 7 patients to visualize the nondilated bile ducts and guide percutaneous transhepatic biliary drainage, thus facilitating the intraductal cooling-assisted thermal ablation process. The procedures were technically successful in all 7 patients, and no major complications were recorded during the follow-up period.

Morbid Obesity's Silver Lining: An Armor for Hollow Viscus in Blunt Abdominal Trauma.

BACKGROUND: Morbid obesity is usually accompanied by both subcutaneous and visceral fat accumulation. Fat can mimic an air bag, absorbing the force of a collision. We hypothesized that morbid obesity is mechanically protective for hollow viscus organs in blunt abdominal trauma (BAT). METHODS: The National Trauma Data Bank (NTDB) was queried for BAT patients from 2013 to 2015. We looked at the rate of gastrointestinal (GI) tract injuries in all BAT patients with different BMIs. A subset analysis of BAT patients with operative GI tract injuries was performed to evaluate the need for abdominal operation. Multivariate analyses were carried out to identify factors independently associated with increased GI tract injuries and associated abdominal operations. RESULTS: A total of 100,459 BAT patients were evaluated in the NTDB. Patients with GI tract injury had a lower proportion of morbidly obese patients [body weight index (BMI) ≥ 40 kg/m2)] (3.7% vs. 4.2%, p = 0.015) and instead had more underweight patients (BMI < 18.5) (5.9% vs. 5.0%, p < 0.001). The risk of GI tract injury decreased 11.6% independently in morbidly obese patients and increased 15.7% in underweight patients. Of the patients with GI tract injuries (N = 11,467), patients who needed a GI operation had a significantly lower proportion of morbidly obese patients (3.2% vs. 5.3%, p < 0.001). The risk of abdominal operation for GI tract injury decreased 57.3% independently in morbidly obese patients. Compared with underweight patients, morbidly obese patients had significantly less GI tract injury (6.0% vs. 13.3%, p < 0.001) and associated abdominal operation rates (65.2% vs. 73.3%, p < 0.001). CONCLUSION: Obesity is protective in BAT. This translates into lower rates of GI tract injury and operation in morbidly obese patients. In contrast, underweight patients appear to suffer a higher rate of GI tract injury and associated GI operations.

Previous Laparotomy Scar Preventing Abdominal Injury from Gunshot Wound.

Diagnostic laparoscopy has been used in select patients with penetrating abdominal trauma. Here we present a case report where a midline surgical scar from a previous trauma laparotomy potentially prevented intra-abdominal injury. Furthermore, laparoscopy was used to exclude other intra-abdominal injuries and retrieve the projectile from within a hematoma cavity. This avoided the morbidity of a trauma laparotomy.

An experimental study in six fresh human cadavers using a novel approach to avoid abdominal wall incisions in total colectomy: totally transanal laparoendoscopic single-site pull-through colectomy with J-pouch creation.

BACKGROUND: The use of transanal laparoscopic access to completely avoid abdominal wall incisions represents the most current evolution in minimally invasive surgery. The combination of single-site surgery and natural orifice transluminal endoscopic surgery (NOTES™) can be used for totally transanal laparoendoscopic pull-through colectomy with J-pouch creation (TLPC-J). The aim of the present study was to provide evidence for the feasibility of TLPC-J in adult human cadavers. METHODS: TLPC-J was performed in six fresh adult human cadavers. The procedure involved endorectal submucosal dissection from 1 cm above the dentate line to a point above the peritoneal reflection, where the rectal muscle was divided circumferentially. The edge of the mucosal cuff was closed distally in order to prevent fecal contamination and the endorectal tube was placed back into the abdomen. A Triport+™ or QuadPort+™ system was introduced transanally, and it served as a multiport device (MD). Resection of the entire colon, mobilization of the distal ileal segment, and extracorporeal suture of the ileal J-loop were performed via the transanal approach. The J-pouch was created using Endo GIA™. After removal of the MD, the J-pouch was sutured to the rectal wall. RESULTS: TLPC-J was performed in all cadavers, with a mean operation duration of 236 ± 22 min. Conversion to either transabdominal laparoscopy or laparotomy was not required in any of the cadavers. No bowel perforation or damage to other organs was observed. The use of a curved endoscope greatly facilitated visualization during transanal laparoscopic dissection for partial and total colectomy, making the procedure feasible. All specimens were retrieved through the anus, eliminating the need for additional transabdominal incisions. CONCLUSIONS: TLPC-J was technically feasible in adult human cadavers, and abdominal wall incisions were not required. However, clinical studies are needed to determine its feasibility in living adults.

Injury patterns of rear seat occupants in frontal impact: an in-depth crash investigation study.

OBJECTIVE: Rear seat occupants are now at a higher risk of injury relative to front seat occupants and there is a need for enhanced protection. This study aimed to examine the pattern of injury, injury mechanisms and injury sources to restrained motor vehicle rear seat occupants involved in a frontal impact. METHODS: Cases involving restrained rear seat occupants aged 9 years and older involved in frontal crashes were prospectively collected from in-depth crash investigations collected in New South Wales and Victoria, Australia, between 2000 and 2010. Structured occupant and driver interviews were conducted to ascertain crash parameters, medical records were reviewed and detailed injury descriptions were recorded using the abbreviated injury scale (AIS). Vehicle and scene inspections were also conducted and injury sources determined. RESULTS: The dataset included 29 rear seat occupants aged 9-80 years. AIS2+ injuries were most commonly observed in the chest and abdomen. Chest injuries were more commonly observed in older occupants, while abdominal and thoracolumbar spine injuries were mostly observed in younger occupants. The seat belt was the most common source of injury to rear seat occupants. CONCLUSIONS: The seat belt is the most common source of injury to rear seat passengers in frontal impact with variations in injury with age. There is a need to provide appropriate belt fit and better control seat belt loads for rear seat passengers. This could be achieved, at least in part, with existing technologies currently used in front seat positions, although novel technologies may also be useful.

Defining the essential anatomical coverage provided by military body armour against high energy projectiles.

INTRODUCTION: Body armour is a type of equipment worn by military personnel that aims to prevent or reduce the damage caused by ballistic projectiles to structures within the thorax and abdomen. Such injuries remain the leading cause of potentially survivable deaths on the modern battlefield. Recent developments in computer modelling in conjunction with a programme to procure the next generation of UK military body armour has provided the impetus to re-evaluate the optimal anatomical coverage provided by military body armour against high energy projectiles. METHODS: A systematic review of the literature was undertaken to identify those anatomical structures within the thorax and abdomen that if damaged were highly likely to result in death or significant long-term morbidity. These structures were superimposed upon two designs of ceramic plate used within representative body armour systems using a computerised representation of human anatomy. RESULTS AND CONCLUSIONS: Those structures requiring essential medical coverage by a plate were demonstrated to be the heart, great vessels, liver and spleen. For the 50th centile male anthropometric model used in this study, the front and rear plates from the Enhanced Combat Body Armour system only provide limited coverage, but do fulfil their original requirement. The plates from the current Mark 4a OSPREY system cover all of the structures identified in this study as requiring coverage except for the abdominal sections of the aorta and inferior vena cava. Further work on sizing of plates is recommended due to its potential to optimise essential medical coverage.

Guidelines for chest drain insertion may not prevent damage to abdominal viscera.

OBJECTIVES: Guidelines to improve the ease and safety of chest drain insertion recommend using the fifth intercostal space, around the midaxillary line (MAL). This study aimed to assess whether compliance with published guidelines reliably ensured such placement and avoided the potentially serious complications of subdiaphragmatic insertion and peripheral nerve injury. METHODS: Three international guidelines were assessed by identifying the intercostal space for chest drain insertion using 16 cadavers (32 sides) at a point 1 cm anterior to MAL. The European Trauma Course method was compared with the British Thoracic Society's 'safe triangle' and the ATLS course technique. RESULTS: The level most commonly found was the sixth intercostal space (43%; 41 of 96 sides). Overall the sixth space or below was found in 83% of insertions (80 of 96 sides). In the fifth intercostal space, the long thoracic nerve ran posterior to the marker placed in all cases and the lateral cutaneous branches of intercostal nerves arose anteriorly to the marker in all but one case. CONCLUSIONS: The results suggest these guidelines may result in insertion of chest drains below the fifth intercostal space, potentially risking injury to subdiaphragmatic structures. Peripheral nerves of the lateral thoracic wall appear safe from incisions 1 cm anterior to MAL.

Finding the fifth intercostal space for chest drain insertion: guidelines and ultrasound.

OBJECTIVES: International guidelines exist for chest drain insertion and recommend identifying the fifth intercostal space or above, around the midaxillary line. In a recent study, applying these guidelines in cadavers risked insertion in the 6th intercostal space or below in 80% of cases. However, there are limitations of cadaveric studies and this investigation uses ultrasound to determine the intercostal space identified when applying these guidelines in healthy adult volunteers. METHODS: On each side of the chest wall in 31 volunteers, the position for drain insertion was identified using the European Trauma Course method, Advanced Trauma Life Support (ATLS) method, British Thoracic Society's 'safe triangle' and the 'traditional' method of palpation. Ultrasound imaging was used to determine the relationship of the skin marks with the underlying intercostal spaces. RESULTS: Five methods were assessed on 60 sides. In contrast to the cadaveric study, 94% of skin marks lay over a safe intercostal space. However, the range of intercostal spaces found spanned the second to the seventh space. In 44% of women, the inferior boundary of the 'safe triangle' and the ATLS guidelines located the sixth intercostal space or below. CONCLUSIONS: Current guidelines often identify a safe site for chest drain insertion, although the same site is not reproducibly found. In addition, women appear to be at risk of subdiaphragmatic drain insertion when the nipple is used to identify the fifth intercostal space. Real-time ultrasonography can be used to confirm the intercostal space during this procedure, although a safe guideline is still needed for circumstances in which ultrasound is not possible.

The impact of seat belts and airbags on high grade renal injuries and nephrectomy rate in motor vehicle collisions.

PURPOSE: Motor vehicle collisions are the most common cause of blunt genitourinary trauma. We compared renal injuries with no protective device to those with seat belts and/or airbags using NTDB. Our primary end point was a decrease in high grade (grades III-V) renal injuries with a secondary end point of a nephrectomy rate reduction. MATERIALS AND METHODS: The NTDB research data sets for hospital admission years 2010, 2011 and 2012 were queried for motor vehicle collision occupants with renal injury. Subjects were stratified by protective device and airbag deployment. The AIS was converted to AAST renal injury grade and nephrectomy rates were evaluated. Intergroup comparisons were analyzed for renal injury grades, nephrectomy, length of stay and mortality using the chi-square test or 1-way ANOVA. The relative risk reduction of protective devices was determined. RESULTS: A review of 466,028 motor vehicle collisions revealed a total of 3,846 renal injuries. Injured occupants without a protective device had a higher rate of high grade renal injuries (45.1%) than those with seat belts (39.9%, p = 0.008), airbags (42.3%, p = 0.317) and seat belts plus airbags (34.7%, p <0.001). Seat belts (20.0%), airbags (10.5%) and seat belts plus airbags (13.3%, each p <0.001) decreased the nephrectomy rate compared to no protective device (56.2%). The combination of seatbelts and airbags also decreased total hospital length of stay (p <0.001) and intensive care unit days (p = 0.005). The relative risk reductions of high grade renal injuries (23.1%) and nephrectomy (39.9%) were highest for combined protective devices. CONCLUSIONS: Occupants of motor vehicle collisions with protective devices show decreased rates of high grade renal injury and nephrectomy. Reduction appears most pronounced with the combination of seat belts and airbags.

Pediatric nonaccidental abdominal trauma: what the radiologist should know.

Abdominal injury in nonaccidental trauma (NAT) is an increasingly recognized cause of hospitalization in abused children. Abdominal injuries in NAT are often severe and have high rates of surgical intervention. Certain imaging findings in the pediatric abdomen, notably bowel perforation and pancreatic injury, should alert the radiologist to possible abuse and incite close interrogation concerning the reported mechanism of injury. Close inspection of the imaging study is warranted to detect additional injury sites because these injuries rarely occur in isolation. When abdominal injury is suspected in known or speculated NAT, computed tomography (CT) of the abdomen and pelvis with intravenous contrast material is recommended for diagnostic and forensic evaluation. Although the rate of bowel injury is disproportionately high in NAT, solid organs, including the liver, pancreas, and spleen, are most often injured. Adrenal and renal trauma is less frequent in NAT and is generally seen with multiple other injuries. Hypoperfusion complex is a constellation of abdominal CT findings that indicates current or impending decompensated shock and is most often due to severe neurologic impairment in NAT. Although abdominal injuries in NAT are relatively uncommon, knowledge of injury patterns and their imaging appearances is important for patient care and protection.

Frontal-Crash Occupant Protection in the Rear Seat: Submarining and Abdomen/Pelvis Response in Midsized Male Surrogates.

Frontal-crash sled tests were conducted to assess submarining protection and abdominal injury risk for midsized male occupants in the rear seat of modern vehicles. Twelve sled tests were conducted in four rear-seat vehicle-bucks with twelve post-mortem human surrogates (PMHS). Select kinematic responses and submarining incidence were compared to previously observed performance of the Hybrid III 50th-percentile male and THOR-50M ATDs (Anthropomorphic Test Devices) in matched sled tests conducted as part of a previous study. Abdominal pressure was measured in the PMHS near each ASIS (Anterior Superior Iliac Spine), in the inferior vena cava, and in the abdominal aorta. Damage to the abdomen, pelvis, and lumbar spine of the PMHS was also identified. In total, five PMHS underwent submarining. Four PMHS, none of which submarined, sustained pelvis fractures and represented the heaviest of the PMHS tested. Submarining of the PMHS occurred in two out of four vehicles. In the matched tests, the Hybrid III never underwent submarining while the THOR-50M submarined in three out of four vehicles. Submarining occurred in vehicles having both conventional and advanced (pretensioner and load limiter) restraints. The dominant factors associated with submarining were related to seat pan geometry. While the THOR-50M was not always an accurate tool for predicting submarining in the PMHS, the Hybrid III could not predict submarining at all. The results of this study identify substantive gaps in frontal-crash occupant protection in the rear seat for midsized males and elucidates the need for additional research for rear-seat occupant protection for all occupants.

Abdominal impacts of handlebar injuries in the PIPER child model: a prevention study.

Aim: Analysis of data from bicycle accidents reveals that handlebar impacts are a significant cause of injury, particularly among children. Despite existing safety regulations, such as helmet requirements, little attention is given to abdominal injuries. The aim of this study is to investigate the influence of handlebar ends on abdominal loading during bicycle crashes. Methods: This study delves into the impact of five different handlebar designs on abdominal injuries during bicycle crashes, using finite element simulations with detailed Human Body Models (HBMs) of a six-year-old child (PIPER child model, Version 0.99.0). Four impact locations were identified in the injury scenario, selected according to the anatomical location of the most commonly injured organs, liver, pancreas, spleen and abdomen. Results: Grip design features, such as shape and rigidity, significantly influence injury outcomes. Grips designed specifically for children demonstrate superior performance in reducing abdominal loading and injury metrics compared to standard grips. The highest injury potential was seen in a damaged handlebar end. Conclusion: These findings underscore the importance of improved handlebar designs and standardized safety measures, especially for children. Implementation of such measures could mitigate the significant health and economic burden associated with handlebar-related injuries and enhance overall bicycle safety for children.

Trend of severe abdominal injuries from bicycle accidents in children: a preventable condition.

AIM: Bicycle riding is a common recreational and sport activity enjoyed by many children. Bicycle accidents are a common cause of abdominal injuries. We aim to establish the trend and the associated risk factor(s) of bicycle-related abdominal injuries. METHODS: A retrospective review of all children admitted following bicycle accidents to a single tertiary referral centre was carried out over an approximately 5-year period. The data were tabulated and regression analyses were carried out. RESULTS: Over the study period, 196 children were admitted into the Emergency Department. Abdominal injuries (16%) were the third largest group after orthopaedic and head injuries. There were 19 major visceral injuries, seven of whom underwent major surgeries. Forty-two percent (8/19) of these major injuries were related to stunts. Over the same period, no child with head injury required any surgical intervention. In addition, there was a definite trend that abdominal injuries were accounting for greater percentage of bicycle-related injuries in children. CONCLUSIONS: Severe intra-abdominal trauma following bicycle injuries appears to be seen more often in adolescent males, especially when related to BMX stunts. These injuries have surpassed head injuries as the prime cause of morbidity from bicycle accidents. These injuries are largely preventable.

NOTES: 'pre-dilatation' as a remedy for technical issues during transgastric access.

OBJECTIVE: To identify and resolve procedural issues during transgastric access for the Natural Orifice Translumenal Endoscopic Surgery (NOTES), where feasibility and safety is established in animals and humans. However, several technical problems during viscerotomy result in considerable delay or procedure failure. METHODS: Gastrotomy was performed under general anaesthesia in survival canine models. Single channel (adult) colonoscope was used. Anterior gastric wall was punctured in mid corpus region with needle knife method and percutaneous endoscopic gastrotomy (PEG) technique in separate dogs. Post-operatively, animal was observed for 2 weeks but it was immediately sacrifised if the creation of viscerotomy had failed. Postmortem examination of these animals focused on the cause of failure and detection of visceral injury. On account of frequent complications, needle knife method was replaced with percutaneous endoscopic gastrotomy technique. Visceral aperture was successfully accomplished with over-the-wire (OTW) balloon dilators after 'pre-dilatation' of the primary puncture with over-the-wire plastic bougies. RESULTS: Gastrotomy was performed in dogs (23) using two methods: needle knife (4) and PEG (19). Initially, there were 5 failures: needle knife (3); PEG (2). The failures resulted from organ damage (2) and inability to insert over-the-wire balloon dilator into gastric puncture (3). The needle knife method was abandoned due to major complications in 4 animals: gastric bleeding (2); liver rupture (1); penetrating injury to anterior abdominal wall (1). Viscerotomy was achieved in (17) consecutive cases by 'pre-dilating' the site of initial puncture. There was no mortality. CONCLUSION: 'Pre-dilatation' with over-the-wire plastic dilators is recommended for the creation of gastrotomy.

Validating the danger of vehicular protective devices and bowel injury.

INTRODUCTION: Protective devices such as seat belts and airbags have improved the safety of motor vehicle occupants, but limited data suggest they may be associated with increased blunt bowel (small bowel or colon) injuries (BI). Unfortunately, this risk is unquantified. METHODS: We analyzed the National Trauma Data Bank (2017-2019) using ICD-10 codes to identify adult motor vehicle occupants with BI who underwent surgical repair. We used logistic regression modeling to compare the risk of undergoing surgical repair for BI after using a protective device. RESULTS: Of 2,848,592 injured patients, 475,546 (16.7%) were motor vehicle occupants. Only 1.2% (n = 5627/475,546) of patients underwent a bowel repair or resection. Using a seat belt only was associated with an adjusted OR of 2.09 (95% CI 1.91, 2.28) for undergoing a bowel repair/resection when adjusting for Injury Severity Score (ISS) and age. Airbag deployment without a seat belt had an adjusted OR of 1.46 (95% CI 1.31, 1.62), while both devices combined conferred an OR of 3.27 (95% CI 3.02, 3.54). However, using a seat belt was protective against death with an OR of 0.50 (95% CI 0.48, 0.53), adjusted for age, sex, Charlson Comorbidity Score, and ISS. CONCLUSION: Seat belts and airbags are essential public health safety interventions and protect against death in motor vehicle-associated injuries. However, patients involved in MVCs with airbag deployment or while wearing a seat belt are at an increased risk of bowel injury requiring surgery compared to unrestrained patients, despite these events being relatively uncommon.

Mitigation of abdominal scars during MR-guided focused ultrasound treatment of uterine leiomyomas with the use of an energy-blocking scar patch.

PURPOSE: To assess the clinical potential of using an energy-blocking scar patch for magnetic resonance-guided focused ultrasound (MRgFUS) treatment of uterine leiomyomas in patients with abdominal scars. MATERIALS AND METHODS: A prospective, nonrandomized, single-arm study was conducted in 20 patients (mean age, 41.1 y; range, 33-51 y) with symptomatic leiomyomas (mean volume, 170 cm(3); range, 10-689 cm(3)) and abdominal scars (mean width, 3.3 mm; range, 1.5-8 mm; mean length, 131.6 mm; range, 86-178 mm) who underwent MRgFUS with an isolating patch covering the scar. Scar patches composed of US-blocking material were placed on patients' skin to cover the scar before treatment. Immediately after each treatment, contrast-enhanced T1-weighted MR images were acquired, and the nonperfused volume (NPV) ratio was measured to determine the technical success of the treatment. Patients were followed for 3 months after treatment for any procedure-related adverse events. RESULTS: All treatments were completed with no technical problems. No serious adverse events were reported during treatments and during 3 months of follow-up. The mean NPV ratio was 53.5% ± 21%. CONCLUSIONS: The scar patch provides an effective treatment option for patients with uterine leiomyomas and scars in the beam path, who were previously excluded from MRgFUS treatment as a result of an increased risk of skin burns.

How to reduce the risk of organ injuries during surgical instrument insertion in laparoscopic surgery: Pushing/pressing force analysis using forceps with sensors.

INTRODUCTION: In laparoscopic surgery, surgical instruments are inserted from a trocar to the target organ in a blind fashion, which carries a risk of organ injury. To clarify the risks associated with surgical instrument insertion, we measured grip strength and pushing/pressing force during surgical instrument insertion in laparoscopic surgery. METHODS: Using forceps with sensors inside a trocar, 10 urologists performed a laparoscopic procedure in pigs, in which they were asked to touch the abdominal wall. The surgeons closed their eyes during the procedure and stopped moving the forceps when they felt them come into contact with the abdominal wall. They were ordered to grip the forceps strongly or softly and to move them rapidly or slowly during the procedure. Grip strength and the pushing/pressing force when the forceps hit the abdominal wall were measured and analyzed. RESULTS: The mean pushing/pressing force when the surgeons gripped the forceps strongly and moved them rapidly (strong/rapid), strongly/slowly, softly/rapidly, and softly/slowly were 2.8, 2.0, 1.7, and 1.1 N, respectively. The pushing/pressing force was significantly greater when the surgeons gripped the forceps strongly, regardless of the forceps speed (P < .001). The pushing/pressing force was significantly greater when the surgeons moved the forceps rapidly, regardless of grip strength (P < .001). CONCLUSIONS: When surgeons insert laparoscopic instruments through trocars, the instruments should be gripped softly and moved slowly to avoid organ injuries.

Effects of seat belts worn by pregnant drivers during low-impact collisions.

OBJECTIVE: The aim of this study was to understand the injury mechanisms of pregnant drivers and associated fetal outcomes. STUDY DESIGN: Frontal and rear impact tests using a dummy representing the anthropometry of a pregnant woman were conducted. RESULTS: In frontal impact tests without a seat belt, abdominal pressure peaked at the point where the dummy contacted the steering wheel. Rear impact tests without a seat belt showed that the dummy moved forward because of rebound and contacted the steering wheel, which was avoided when a seat belt was worn. CONCLUSION: Wearing a seat belt reduces abdominal pressure or prevents contact with the steering wheel during collisions.

Defining the medical coverage of ballistic protection to the pelvis and thigh.

INTRODUCTION: Pelvis, lower limb and associated genital injury caused by explosive devices was responsible for mortality and considerable long-term morbidity for the UK Armed Forces during combat operations in Afghanistan, resulting in the issue of a pelvic protection system in 2010. The aim of this current research was to determine the medical coverage of the pelvis and thigh and to define the vertical dimensions of ballistic protective material for future pelvic protection (PP). METHOD: CT scans from 120 male UK Armed Forces personnel were analysed to identify the anthropometric landmarks and vertical boundaries of coverage for the pelvis and thigh. Pelvic height was the vertical distance between the upper border of the iliac crest in the midaxillary plane to the most inferior point of the ischial tuberosity of the pelvis. Upper thigh height was proposed as a 100 mm fixed distance below the ischial tuberosities, enabling a tourniquet to be reproducibly applied. These distances were compared with the ballistic component of the five sizes of tier 1 PP using a paired t-test. RESULTS: The vertical components of coverage measured using CT scans were all significantly less (p<0.01) compared with all five sizes of tier 1 PP; for example, the ballistic component of the smallest size of tier 1 PP measured 410 mm, which was larger than the 99th percentile male, which measured 346 mm on CT scans. CONCLUSIONS: While all sizes of tier 1 PP provide coverage to the pelvis and upper thigh structures, there is an opportunity to optimise future PP. For example, comparing the large size of tier 1 PP to the 50th percentile male demonstrated an opportunity to reduce the ballistic protective component by 31%. Reducing the quantity of material used will improve heat dissipation and user comfort and reduce material mass and acquisition costs.