Modern weapon-mounted technologies, such as novel sighting devices, detachable grenade launchers, and telescopic butt stocks, add considerable weight to weapons and alter the center of mass (COM). Currently, few objective studies have investigated the effects of these alterations on soldiers’ rifle handling. The purpose of this study was to examine the effect of weight and weight distribution on upper extremity muscular fatigue during static rifle aiming. Custom testing rigs were designed to allow the weight and COM of the in-service C7A2 assault rifle to be altered using supplementary weights and an adjustable rail system. Seven rifle configurations, each of which represented the weight and COM of a potential future design, were assessed. Soldiers performed static rifle holds with each of the rifle configurations. Upper extremity muscle activity was monitored using surface electromyography (EMG) and a subjective scale of perceived exertion. Dependent measures included muscular activity level (integrated EMG), rate of muscular fatigue (slope of the median power frequency), and subjective ratings of perceived exertion (Borg CR10 scale). The body areas exhibiting the most muscular strain throughout testing were also subjectively assessed using a body map. The results revealed that the muscle activation levels of the supporting arm were substantially greater (>30% increase) when the COM was shifted forward 7cm. This objective finding was supported by the soldiers’ subjective perceptions of muscle effort. Conversely, muscle activity levels did not make evident the effects of added weight; although this may have been largely due to the fact that muscle activity from the lower back was not captured. Rates of muscle fatigue were found to be greater in the anterior deltoid than other extremity muscles and fatigue levels were greater in the supporting arm than the trigger arm. However, using rates of fatigue it was not possible to differentiate between weight conditions and COM positions. Despite the limitations of this study, it has provided a starting point toward developing a standardized protocol for assessing muscular demands during rifle aiming. / Thesis (Master, Kinesiology & Health Studies) -- Queen's University, 2009-09-18 10:24:26.909

There are two opinions as to the effectiveness of the Pennsylvania Rifle during the Revolutionary War. On one hand it is alleged that the rifle was, at best, not particularly useful, and that its disadvantages outweighed its advantages. In contradiction to this we find that the British military appealed to London for rifles, and that the British government specified that there be a definite number of riflemen among the mercenaries they hired. Furthermore, according to Fortescue, the British military were forced to change their tactics, at least in part, because of the rifle. It is the purpose of this thesis to resolve this conflict by determining which of the two positions, if either ,is correct, or to determine the extent to which they may both be correct.

Thesis (M.A.)--University of Wisconsin--Madison, 1960. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [219]-224).

Thesis(M.S.)--Auburn University, 2006. / Abstract. Includes bibliographic references.

Fifty-two rifle naïve navy personnel underwent four days of simulated M16A1 live fire training in an artificial intelligent test bed trainer, followed by one day of live fire record qualification in the field. Prior to test bed training, subjects were administered the Army Physical Readiness Test (APRT) and assessed on their current level of physical fitness. At the end of test bed training the subjects participated in one of four exercise conditions (control, walk, job, or run) designed to elevate their hart rates. Immediately following exercise they shot a 10 round self-paced task at a scaled 250 meter target. Analysis of variance indicated no significant difference between fitness levels for the shot group size and standard deviation on the self-paced task. Significant differences were found based on exercise condition and heart rate during firing. Future research should utilize experienced marksmen and the exercise manipulation should occur immediately prior to live fire.

This study aims at evaluating the clinical outcomes with the use of Polymyxin B, antibiotic that is being increasingly used across the current needs of antimicrobial therapy. Was developed in the 40s for the treatment of gram-negative bacilli, and fell into disuse because of its toxicity, mainly renal. Despite this increased use is poorly understood its true efficacy and its toxicity profile (ZAVASCKI et al., 2010, p.71). Among the clinical outcomes analyzed the mortality at 30 days and the occurrence of acute kidney injury (AKI). This evaluation was made by means of a retrospective cohort study, based on data collection from medical records of adult patients admitted to the University Hospital of Santa Maria (HUSM), who received Polymyxin B for more than 48 hours. For evaluation of the nephrotoxicity RIFLE criteria were used. The diagnosis of infection was made according to the criteria of the National Health Surveillance Agency (Anvisa). We evaluated 53 patients, mean age 56 years, 29 (55%) men and 24 (45%) women. AKI occurred in 25 (53%) participants, with an average start of 8.5 (± 4.9) days. In thirty days, 12 (48%) patients showed improvement of renal function to pretreatment levels. Doses above 25 mg / kg / day and previous normal renal function, doses were positively correlated with worsening kidney. Regarding the clinical outcome observed that 29 (55%) had a favorable outcome at 14 days. Eighteen (34%) participants died within 30 days after initiation of treatment. As risk factors for death were found combined use with other active drug to BGN resistant to carbapenems (p-value 0.028, RR 13 CI 1.3 to 130), and SOFA score greater than eight (p-value <0.029, RR 1.3 CI 15 to 179). The conclusion is based on these findings, the mortality related to use of Polymyxin B is dependent on the degree of comorbidities presented by the patient (SOFA) and the use or not of combination therapy. This last finding may be due to a bias of severity of infection. When it was found that nephrotoxicity is an agent with nephrotoxic potential, and that the occurrence of AKI is influenced by the prescribed daily dosage. The fact of the LRA have been more frequent in patients without renal injury corroborates the hypothesis that greater care with other causative factors for AKI may decrease its occurrence in patients using polymyxin B. / Este estudo tem como objetivo a avaliação dos desfechos clínicos com a utilização da Polimixina B, antibiótico que vem sendo cada vez mais utilizado frente às necessidades atuais de terapia antimicrobiana. Foi desenvolvido na década de 40 para o tratamento de bacilos gram-negativos (BGN) e, entrou em desuso devido a sua toxicidade, principalmente renal. Apesar deste crescente uso permanece pouco entendidos a sua real eficácia e seu perfil de toxicidade (ZAVASCKI et al., 2010, p.71). Dentre os desfechos clínicos analisados incluíram-se a mortalidade em 30 dias e a ocorrência de lesão renal aguda (LRA). Essa avaliação foi feita por meio de uma coorte retrospectiva, baseada na coleta de dados do prontuário médico de pacientes adultos, internados no Hospital Universitário de Santa Maria (HUSM), que receberam Polimixina B por mais de 48 horas. Para avaliação da nefrotoxicidade foram utilizados os critérios Risk Injury Failure Loss Endstage renal disease(RIFLE). O diagnóstico das infecções foi feito conforme os critérios da Agência Nacional de Vigilância Sanitária (ANVISA). Foram avaliados 53 pacientes, com idade média de 56 anos, sendo 29 (55%) homens. Ocorreu LRA em 25 (47%) participantes, com média de início de 8,5 (±4,9) dias. Em trinta dias, 12 (48%) dos pacientes apresentaram melhora da função renal a níveis pré-tratamento. Doses superiores a 25 mg/Kg/dia e função renal prévia normal, tiveram correlação positiva com a piora renal. Quanto ao desfecho clínico observamos que 29 (55%) tiveram um desfecho favorável em 14 dias. Dezoito (34%) participantes faleceram em 30 dias após o início do tratamento. Como fatores de risco para o óbito foram encontrados o uso combinado com outra droga ativa para BGN resistente à carbapenêmicos (p-valor 0,028, RR 13 IC 1,3-130), e escore SOFA superior a oito (p-value <0.029, RR 15 CI 1,3 to 179). Conclui-se com base nesses achados, que a mortalidade relacionada com uso da Polimixina B é dependente do grau de co-morbidades apresentado pelo paciente (escore SOFA) e do uso ou não de terapia combinada. Podendo esse ultimo achado dever-se a um viés de gravidade da infecção. Quando a nefrotoxicidade encontrou-se que é um agente com potencial nefrotóxico, e que a ocorrência da LRA é influenciada pela dose diária prescrita. O fato da LRA ter sido mais frequente em pacientes sem lesão renal prévia corrobora com a hipótese de que um maior cuidado com outros fatores causadores de LRA pode diminuir sua ocorrência em pacientes que utilizam Polimixina B.

This thesis consisted of two main research themes: 1) The biomechanics of military load carriage, and 2) injuries and discomfort caused by load carriage. Although different in their methodological approaches, the two sections are linked and integral to each other. Harman et al (2000) suggest that the biomechanical analysis of military load carriage, and in particular the study of ground reaction forces (GRF), is relevant to the understanding and prevention oflower extremity injuries. The general aims of the biomechanical analysis of load carriage were to determine the effect that heavy load carriage, rifle carriage and load distribution has on GRF parameters. In addition to determining the mechanisms behind these potential changes, base-line data for British military load carriage systems (LCS) were also established. An important factor for the thesis was to consider the LCS as a single unit (where possible) and not its individual components, for example the backpack alone. The final biomechanical study involved a 3D, bi-Iateral gait analysis of load carriage; with this type of analysis being rare in the published literature. Results from the biomechanical studies showed that GRF parameters increased proportionally to applied load, even when heavy loads of up to 40 kg were carried. Also seen was an increase in mediolateral impulse and stance time with greater carried load. Another area which has received little or no attention in the literature is the effect of rifle carriage on gait. This thesis showed that rifle carriage changed basal gait patterns as observed in the GRF parameters. The most noteworthy results were an increase in impact peak and mediolateral impulse. The mechanism behind these changes is most likely to be a restriction of natural arm swing induced by rifle carriage. Distributing load more evenly around the body had limited effect on the GRF parameters measured. However, some important changes were observed. These were an increase in force minimum and a decrease in maximum braking force at the heaviest load. The latter effect has been strongly linked to an increase in the incidence of foot blisters within the literature. Finally, the gait analysis study showed significant increases in joint moments and torques with carried load. Also observed was a decrease in stride length and increase in percentage double support and stance. The main kinematic differences were a decrease in range of motion at the knee and pelvis rotation, and an increase in pelvis tilt as load is added. Four further studies were conducted in an effort to determine the discomfort and injury caused by load carriage. The first 3 studies collected sUbjective discomfort data via interviews, questionnaires and the use of comfort ratings. All of which were collected either during or after a prolonged period of load carriage by military personnel. Results gleaned from these studies showed that the upper limb is susceptible to short term discomfort following load carriage, whereas the lower limb is not. The lower limb may be at an increased risk of developing medium to long term injuries such as joint degradation and stress fractures. However, foot pain was rated as the most uncomfortable skeletal region of the body following a 1 hour field march with load, and blisters were experienced by around 60% of participants. Shoulder discomfort commences almost as soon as load is added and increases steadily with time. However, foot discomfort seems to increase more rapidly once the discomfort first materialises. This early development of shoulder or foot pain may be a risk factor for severe pain or non-completion of a period of prolonged load carriage. Finally, females experienced more discomfort in the hip joint and feet compared to males. (Continues...).

Thesis (M.S.)--Auburn University, 2007. / Abstract. Includes bibliographic references (ℓ. 54-62)

Thesis (M.A.)--Virginia Polytechnic Institute and State University, 1990. / Vita. Abstract. Includes bibliographical references (leaves 85-90). Also available via the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1974. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.