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1.
Eur Radiol ; 34(4): 2457-2467, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37776361

RESUMO

OBJECTIVES: Diffusion-weighted imaging (DWI) with simultaneous multi-slice (SMS) acquisition and advanced processing can accelerate acquisition time and improve MR image quality. This study evaluated the image quality and apparent diffusion coefficient (ADC) measurements of free-breathing DWI acquired from patients with liver metastases using a prototype SMS-DWI acquisition (with/without an advanced processing option) and conventional DWI. METHODS: Four DWI schemes were compared in a pilot 5-patient cohort; three DWI schemes were further assessed in a 24-patient cohort. Two readers scored image quality of all b-value images and ADC maps across the three methods. ADC measurements were performed, for all three methods, in left and right liver parenchyma, spleen, and liver metastases. The Friedman non-parametric test (post-hoc Wilcoxon test with Bonferroni correction) was used to compare image quality scoring; t-test was used for ADC comparisons. RESULTS: SMS-DWI was faster (by 24%) than conventional DWI. Both readers scored the SMS-DWI with advanced processing as having the best image quality for highest b-value images (b750) and ADC maps; Cohen's kappa inter-reader agreement was 0.6 for b750 image and 0.56 for ADC maps. The prototype SMS-DWI sequence with advanced processing allowed a better visualization of the left lobe of the liver. ADC measured in liver parenchyma, spleen, and liver metastases using the SMS-DWI with advanced processing option showed lower values than those derived from the SMS-DWI method alone (t-test, p < 0.0001; p < 0.0001; p = 0.002). CONCLUSIONS: Free-breathing SMS-DWI with advanced processing was faster and demonstrated better image quality versus a conventional DWI protocol in liver patients. CLINICAL RELEVANCE STATEMENT: Free-breathing simultaneous multi-slice- diffusion-weighted imaging (DWI) with advanced processing was faster and demonstrated better image quality versus a conventional DWI protocol in liver patients. KEY POINTS: • Diffusion-weighted imaging (DWI) with simultaneous multi-slice (SMS) can accelerate acquisition time and improve image quality. • Apparent diffusion coefficients (ADC) measured in liver parenchyma, spleen, and liver metastases using the simultaneous multi-slice DWI with advanced processing were significantly lower than those derived from the simultaneous multi-slice DWI method alone. • Simultaneous multi-slice DWI sequence with inline advanced processing was faster and demonstrated better image quality in liver patients.


Assuntos
Neoplasias Hepáticas , Respiração , Humanos , Reprodutibilidade dos Testes , Neoplasias Hepáticas/diagnóstico por imagem , Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos
2.
J Strength Cond Res ; 38(6): e304-e309, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38320231

RESUMO

ABSTRACT: Roberts, BM, Staab, JS, Caldwell, AR, Sczuroski, CE, Staab, JE, Lutz, LJ, Reynoso, M, Geddis, AV, Taylor, KM, Guerriere, KI, Walker, LA, Hughes, JM, and Foulis, SA. Sex does not affect changes in body composition and insulin-like growth factor-I during US Army basic combat training. J Strength Cond Res 38(6): e304-e309, 2024-Insulin-like growth factor 1 (IGF-I) has been implicated as a biomarker of health and body composition. However, whether changes in body composition are associated with changes in IGF-I is unclear. Therefore, we examined the relationship between body composition changes (i.e., fat mass and lean mass) and total serum IGF-I levels in a large cohort of young men ( n = 809) and women ( n = 397) attending US Army basic combat training (BCT). We measured body composition using dual energy x-ray absorptiometry and total serum IGF-I levels during week 1 and week 9 of BCT. We found that pre-BCT lean mass ( r = 0.0504, p = 0.082) and fat mass ( r = 0.0458, p = 0.082) were not associated with pre-BCT IGF-I. Body mass, body mass index, body fat percentage, and fat mass decreased, and lean mass increased during BCT (all p < 0.001). Mean (± SD ) IGF-I increased from pre-BCT (176 ± 50 ng·ml -1 ) to post-BCT (200 ± 50 ng·ml -1 , p < 0.001). Inspection of the partial correlations indicated that even when considering the unique contributions of other variables, increases in IGF-I during BCT were associated with both increased lean mass ( r = 0.0769, p = 0.023) and increased fat mass ( r = 0.1055, p < 0.001) with no sex differences. Taken together, our data suggest that although changes in IGF-I weakly correlated with changes in body composition, IGF-I, in isolation, is not an adequate biomarker for predicting changes in body composition during BCT in US Army trainees.


Assuntos
Composição Corporal , Fator de Crescimento Insulin-Like I , Militares , Humanos , Masculino , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like I/análise , Feminino , Composição Corporal/fisiologia , Adulto Jovem , Fatores Sexuais , Absorciometria de Fóton , Adulto , Estados Unidos , Adolescente , Peptídeos Semelhantes à Insulina
3.
Calcif Tissue Int ; 110(5): 605-614, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35171303

RESUMO

For decades researchers reported that pre-menopausal women who engage in extensive endurance exercise and have menstrual dysfunction can develop low bone mineral density (BMD) or osteoporosis. More recently, low energy availability has been recognized as the initiating factor for low BMD in these women. Furthermore, the relationship between low energy availability and poor skeletal health is not exclusive to women engaging in endurance exercise. Rather, both males and females commonly experience endocrine dysfunction resulting from low energy availability and high exercise levels that degrades skeletal health. Consequences to skeletal health can range from short-term changes in bone metabolism and increased risk of bone stress injuries to long-term consequences of low BMD, such as osteoporosis and related fragility fractures. The degree to which low energy availability degrades skeletal health may be dependent on the length and extent of the energy deficit. However, the complex relationships between under-fueling, short- and long-term skeletal consequences and the factors that mediate these relationships are not well described. In this review, we discuss the consequences of low energy availability on sex hormones and skeletal health in two highly-active populations-athletes and military trainees-and provide a summary of existing knowledge gaps for future study.


Assuntos
Doenças Ósseas , Osteoporose , Adulto , Atletas , Densidade Óssea , Metabolismo Energético , Exercício Físico , Feminino , Humanos , Masculino
4.
Int J Sport Nutr Exerc Metab ; 32(5): 325-333, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35523419

RESUMO

Bone stress injuries (BSIs) are common among athletes and have high rates of recurrence. However, risk factors for multiple or recurrent BSIs remain understudied. Thus, we aimed to explore whether energy availability, menstrual function, measures of bone health, and a modified Female Athlete Triad Cumulative Risk Assessment (CRA) tool are associated with a history of multiple BSIs. We enrolled 51 female runners (ages 18-36 years) with history of ≤1 BSI (controls; n = 31) or ≥3 BSIs (multiBSI; n = 20) in this cross-sectional study. We measured lumbar spine, total hip, and femoral neck areal bone mineral density by dual-energy X-ray absorptiometry, bone material strength index using impact microindentation, and volumetric bone mineral density, microarchitecture, and estimated strength by high-resolution peripheral quantitative computed tomography. Participants completed questionnaires regarding medical history, low-energy fracture history, and disordered eating attitudes. Compared with controls, multiBSI had greater incidence of prior low-energy fractures (55% vs. 16%, p = .005) and higher modified Triad CRA scores (2.90 ± 2.05 vs. 1.84 ± 1.59, p = .04). Those with multiBSI had higher Eating Disorder Examination Questionnaire (0.92 ± 1.03 vs. 0.46 ± 0.49, p = .04) scores and a greater percentage difference between lowest and highest body mass at their current height (15.5% ± 6.5% vs. 11.5% ± 4.9% p = .02). These preliminary findings indicate that women with a history of multiple BSIs suffered more prior low-energy fractures and have greater historical and current estimates of energy deficit compared with controls. Our results provide strong rationale for future studies to examine whether subclinical indicators of energy deficit contribute to risk for multiple BSIs in female runners.


Assuntos
Síndrome da Tríade da Mulher Atleta , Fraturas de Estresse , Absorciometria de Fóton , Adolescente , Adulto , Atletas , Densidade Óssea , Estudos Transversais , Feminino , Fraturas de Estresse/etiologia , Humanos , Adulto Jovem
5.
Aust Occup Ther J ; 69(6): 703-713, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35949169

RESUMO

INTRODUCTION: Australian and New Zealand accreditation standards for occupational therapy courses mandate consumer involvement in the design, delivery, and evaluation of courses. Consumer involvement in medical, dental, and nursing education has been evidenced as a factor for increasing student empathy. To date, there has been no known research on the impact of mental health consumer involvement on occupational therapy students' empathy. The aim of this study was to investigate if occupational therapy students who receive teaching from a mental health consumer demonstrate higher levels of empathy compared with students who receive teaching delivered by occupational therapy academics. METHODS: Pre-post, quasi experimental, two group comparison design was used to measure second-year student empathy pre and post a consumer-led teaching tutorial. Students (N = 217) were randomised into two groups across three university campuses: 'teaching as usual group' (control) or 'consumer-led' group (experimental group). The Jefferson Scale of Empathy was used to measure student empathy. RESULTS: N = 138 matched scales were returned. Little difference in empathy scales was detected between groups. The 'consumer-led' group increased for the empathy scale by 3.4(95% CI: 0.7,6.1, p = 0.014) but was not statistically significant compared to 1.3(95% CI: -1.0,3.5, p = 0.267) for the control group. Both groups scored highly on empathy. CONCLUSION: This study found that occupational therapy students had pre-existing high levels of empathy. The challenge for future research is to identify appropriate ways to measure the impact of mental health consumer involvement on occupational therapy curriculum and students.


Assuntos
Empatia , Terapia Ocupacional , Humanos , Terapia Ocupacional/educação , Saúde Mental , Austrália , Estudantes
6.
Int J Obes (Lond) ; 45(3): 659-665, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33414487

RESUMO

INTRODUCTION: U.S. Army Basic Combat Training (BCT) prepares new recruits to meet soldier physical demands. It also serves as a model of physical changes in healthy young nonobese women and men during an intensive 10-week training program without diet restriction. In this prospective observational study, we quantified the changes in lean mass and body fat induced by BCT in a large sample of men and women undergoing the same physical training program. METHODS: Young women (n = 573) and men (n = 1071) meeting Army health and fitness recruitment standards volunteered to provide DXA-derived body composition data at the beginning and end of BCT. RESULTS: During BCT, there was no change in body mass in women and a 1.7-kg loss in men. Relative body fat (%BF) declined by an average of 4.0 ± 2.4 and 3.4 ± 2.8 percentage points (±SD) for women and men, respectively. The greatest predictor of change in %BF during BCT for both sexes was %BF at the beginning of training. Women and men gained an average 2.7 ± 1.6 kg and 1.7 ± 2.0 kg of lean mass during BCT. CONCLUSIONS: Army BCT produced significant effects on body composition despite minimal changes in total body mass. These findings demonstrate the ability of a 10-week sex-integrated physical training program to positively alter body composition profiles of young adults.


Assuntos
Composição Corporal/fisiologia , Militares/estatística & dados numéricos , Condicionamento Físico Humano , Aptidão Física/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos , Adulto Jovem
7.
Exerc Sport Sci Rev ; 48(3): 140-148, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32568926

RESUMO

We review evidence supporting an updated mechanostat model in bone that highlights the central role of osteocytes within bone's four mechanoadaptive pathways: 1) formation modeling and 2) targeted remodeling, which occur with heightened mechanical loading, 3) resorption modeling, and 4) disuse-mediated remodeling, which occur with disuse. These four pathways regulate whole-bone stiffness in response to changing mechanical demands.


Assuntos
Regeneração Óssea , Reabsorção Óssea , Osteócitos/fisiologia , Adaptação Fisiológica , Animais , Fenômenos Biomecânicos , Osso Cortical/fisiologia , Humanos , Estresse Mecânico , Suporte de Carga/fisiologia
8.
Intern Med J ; 50(9): 1134-1138, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32929820

RESUMO

Association between tumour necrosis alpha inhibitors and weight gain has been reported. We examined weight change in our cohort of inflammatory bowel disease patients treated with infliximab (IFX) for over 12 months, its associations and financial implications. Two-thirds of patients gained weight during the course of therapy. The mean change in weight after 12 months of IFX therapy was 3.3 (±6.5) kg.


Assuntos
Doenças Inflamatórias Intestinais , Fator de Necrose Tumoral alfa , Estudos de Coortes , Humanos , Doenças Inflamatórias Intestinais/induzido quimicamente , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab/efeitos adversos , Aumento de Peso
9.
Calcif Tissue Int ; 105(1): 68-76, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31011765

RESUMO

Musculoskeletal injuries, such as stress fracture, are responsible for over 10-million lost-duty days among U.S. Army Soldiers. During Basic Combat Training (BCT), an 8- to 10-week program that transforms civilians into Soldiers, women are four times more likely than men to sustain a stress fracture. In this work, we performed high-resolution peripheral quantitative computed tomography scans on the ultradistal tibia of 90 female recruits [age = 21.5 ± 3.3 (mean ± standard deviation) years] before the start of BCT and after 8 weeks into BCT. Then, we divided the scanned bone volume into four sectors-lateral, posterior, medial, and anterior-and computed the bone density and microarchitectural parameters in each of the four sectors pre- and post-BCT. We used linear mixed models to estimate the mean difference for bone density and microarchitectural parameters, while controlling for age, race, and pre-BCT body mass index. Our results revealed that the total volumetric bone mineral density, trabecular volumetric bone mineral density, and trabecular thickness increased (p < 0.05) in each of the four sectors. In addition, cortical thickness and trabecular bone volume/total volume increased in both medial and posterior sectors (p < 0.05). Overall, six and five out of nine parameters improved in the medial and posterior sectors, respectively, after BCT. In conclusion, the heightened physical activity during BCT led to the most beneficial bone adaptation in the medial and posterior sectors of the ultradistal tibia, which is indicative of higher loading in these sectors during activities performed in the course of BCT.


Assuntos
Densidade Óssea/fisiologia , Osso e Ossos/patologia , Militares , Tíbia/patologia , Absorciometria de Fóton/métodos , Adulto , Exercício Físico/fisiologia , Feminino , Humanos , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
10.
BMC Musculoskelet Disord ; 20(1): 282, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31185965

RESUMO

BACKGROUND: Musculoskeletal injuries (MSKIs) are common in military trainees and present a considerable threat to occupational fitness, deployability, and overall military readiness. Despite the negative effects of MSKIs on military readiness, comprehensive evaluations of the key known and possible risk factors for MSKIs are lacking. The U.S. Army Research Institute of Environmental Medicine (ARIEM) is initiating a large-scale research effort, the ARIEM Reduction in Musculoskeletal Injury (ARMI) Study, to better understand the interrelationships among a wide range of potential MSKI risk factors in U.S. Army trainees in order to identify those risk factors that most contribute to MSKI and may be best targeted for effective mitigation strategies. METHODS: This prospective study aims to enroll approximately 4000 (2000 male and 2000 female) U.S. Army trainees undergoing Basic Combat Training (BCT). Comprehensive in-person assessments will be completed at both the beginning and end of BCT. Participants will be asked to complete surveys of personal background information, medical history, physical activity, sleep behaviors, and personality traits. Physical measurements will be performed to assess anthropometrics, tibial microarchitecture and whole body bone mineral density, muscle cross-sectional area, body composition, and muscle function. Blood sampling will be also be conducted to assess musculoskeletal, genetic, and nutritional biomarkers of risk. In addition, participants will complete weekly surveys during BCT that examine MSKI events, lost training time, and discrete risk factors for injury. Participants' medical records will be tracked for the 2 years following graduation from training to identify MSKI events and related information. Research hypotheses focus on the development of a multivariate prediction model for MSKI. DISCUSSION: Results from this study are expected to inform current understanding of known and potential risk factors for MSKIs that can be incorporated into solutions that optimize Soldier health and enhance military readiness.


Assuntos
Exercício Físico/fisiologia , Militares/estatística & dados numéricos , Doenças Musculoesqueléticas/epidemiologia , Sistema Musculoesquelético/lesões , Adolescente , Adulto , Projetos de Pesquisa Epidemiológica , Feminino , Humanos , Estudos Longitudinais , Masculino , Doenças Musculoesqueléticas/fisiopatologia , Doenças Musculoesqueléticas/prevenção & controle , Sistema Musculoesquelético/fisiopatologia , Estudos Prospectivos , Fatores de Risco , Estados Unidos/epidemiologia , Adulto Jovem
11.
Br J Community Nurs ; 28(3): 109-110, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36853895
12.
Mol Biol Evol ; 33(4): 885-97, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26668183

RESUMO

The World Health Organization has declared the emergence of antibiotic resistance to be a global threat to human health. Broad-host-range plasmids have a key role in causing this health crisis because they transfer multiple resistance genes to a wide range of bacteria. To limit the spread of antibiotic resistance, we need to gain insight into the mechanisms by which the host range of plasmids evolves. Although initially unstable plasmids have been shown to improve their persistence through evolution of the plasmid, the host, or both, the means by which this occurs are poorly understood. Here, we sought to identify the underlying genetic basis of expanded plasmid host-range and increased persistence of an antibiotic resistance plasmid using a combined experimental-modeling approach that included whole-genome resequencing, molecular genetics and a plasmid population dynamics model. In nine of the ten previously evolved clones, changes in host and plasmid each slightly improved plasmid persistence, but their combination resulted in a much larger improvement, which indicated positive epistasis. The only genetic change in the plasmid was the acquisition of a transposable element from a plasmid native to the Pseudomonas host used in these studies. The analysis of genetic deletions showed that the critical genes on this transposon encode a putative toxin-antitoxin (TA) and a cointegrate resolution system. As evolved plasmids were able to persist longer in multiple naïve hosts, acquisition of this transposon also expanded the plasmid's host range, which has important implications for the spread of antibiotic resistance.


Assuntos
Resistência Microbiana a Medicamentos/genética , Evolução Molecular , Plasmídeos/genética , Pseudomonas/genética , Elementos de DNA Transponíveis/genética , Especificidade de Hospedeiro/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Pseudomonas/efeitos dos fármacos , Pseudomonas/patogenicidade , Análise de Sequência de DNA
13.
J Biomech Eng ; 138(10)2016 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-27437640

RESUMO

Prior studies have assessed the effects of load carriage on the tibia. Here, we expand on these studies and investigate the effects of load carriage on joint reaction forces (JRFs) and the resulting spatiotemporal stress/strain distributions in the tibia. Using full-body motion and ground reaction forces from a female subject, we computed joint and muscle forces during walking for four load carriage conditions. We applied these forces as physiological loading conditions in a finite-element (FE) analysis to compute strain and stress. We derived material properties from computed tomography (CT) images of a sex-, age-, and body mass index-matched subject using a mesh morphing and mapping algorithm, and used them within the FE model. Compared to walking with no load, the knee JRFs were the most sensitive to load carriage, increasing by as much as 26.2% when carrying a 30% of body weight (BW) load (ankle: 16.4% and hip: 19.0%). Moreover, our model revealed disproportionate increases in internal JRFs with increases in load carriage, suggesting a coordinated adjustment in the musculature functions in the lower extremity. FE results reflected the complex effects of spatially varying material properties distribution and muscular engagement on tibial biomechanics during walking. We observed high stresses on the anterior crest and the medial surface of the tibia at pushoff, whereas high cumulative stress during one walking cycle was more prominent in the medioposterior aspect of the tibia. Our findings reinforce the need to include: (1) physiologically accurate loading conditions when modeling healthy subjects undergoing short-term exercise training and (2) the duration of stress exposure when evaluating stress-fracture injury risk. As a fundamental step toward understanding the instantaneous effect of external loading, our study presents a means to assess the relationship between load carriage and bone biomechanics.


Assuntos
Modelos Biológicos , Contração Muscular/fisiologia , Músculo Esquelético/fisiologia , Tíbia/fisiologia , Caminhada/fisiologia , Suporte de Carga/fisiologia , Idoso , Idoso de 80 Anos ou mais , Força Compressiva/fisiologia , Simulação por Computador , Módulo de Elasticidade/fisiologia , Feminino , Análise de Elementos Finitos , Marcha/fisiologia , Humanos , Masculino , Estresse Mecânico , Resistência à Tração/fisiologia
14.
Eur J Appl Physiol ; 114(11): 2251-9, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25027064

RESUMO

PURPOSE: To determine the effects of US Army Ranger Training, an 8-week, physically demanding program (energy expenditure of 2,500-4,500 kcal/day) with energy restriction (deficit of 1,000-4,000 kcal/day) and sleep deprivation (<4 h sleep/night) on bone metabolism. METHODS: Blood was collected from 22 men (age 24 ± 4 years) before and after training. Follow-up measurements were made in a subset of 8 subjects between 2 and 6 weeks after training. Serum was analyzed for bone formation biomarkers [bone alkaline phosphatase (BAP) and osteocalcin (OCN)], bone resorption biomarkers [C-telopeptide cross-links of type I collagen (CTX) and tartrate-resistant acid phosphatase (TRAP5b)], calcium, parathyroid hormone (PTH), and vitamin D 25(OH)D increased significantly by 37.3 ± 45.2 % with training [corrected]. A repeated-measures ANOVA with time as the only factor was used to analyze data on the subset of 8 subjects who completed follow-up data collection. RESULTS: BAP and OCN significantly decreased by 22.8 ± 15.5% (pre 41.9 ± 10.1; post 31.7 ± 7.8 ng/ml) and 21.0 ± 23.3% (pre 15.0 ± 3.5; post 11.3 ± 2.1 ng/ml), respectively, with training, suggesting suppressed bone formation. OCN returned to baseline, while BAP remained suppressed 2-6 weeks post-training. TRAP5b significantly increased by 57.5 ± 51.6% (pre 3.0 ± 0.9; post 4.6 ± 1.4 ng/ml) from pre- to post-training, suggesting increased bone resorption, and returned to baseline 2-6 weeks post-training. PTH Increased significantly by 37.3 ± 45.2% with training. No changes in CTX, calcium, or PTH were detected. CONCLUSIONS: These data indicate that multi-stressor military training results in increased bone resorption and suppressed bone formation, with recovery of bone metabolism 2-6 weeks after completion of training.


Assuntos
Militares , Osteogênese , Treinamento Resistido/efeitos adversos , Estresse Fisiológico , Fosfatase Ácida/sangue , Adulto , Fosfatase Alcalina/sangue , Reabsorção Óssea/etiologia , Restrição Calórica/efeitos adversos , Colágeno Tipo I/sangue , Humanos , Isoenzimas/sangue , Masculino , Osteocalcina/sangue , Hormônio Paratireóideo/sangue , Peptídeos/sangue , Privação do Sono/complicações , Fosfatase Ácida Resistente a Tartarato , Vitamina D/sangue
15.
Eur J Sport Sci ; 24(6): 740-749, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38874992

RESUMO

Lower extremity injuries are prevalent in military trainees, especially in female and older trainees. Modifiable factors that lead to higher injury risk in these subgroups are not clear. The purpose of this study was to identify whether external loading variables during military-relevant tasks differ by age and sex in U.S. Army trainees. Data was collected on 915 trainees in the first week of Basic Combat Training. Participants performed running and ruck marching (walking with 18.1 kg pack) on a treadmill, as well as double-/single-leg drop landings. Variables included: vertical force loading rates, vertical stiffness, first peak vertical forces, peak vertical and resultant tibial accelerations. Comparisons were made between sexes and age groups (young, ≤19 years; middle, 20-24 years; older, ≥25 years). Significant main effects of sex were found, with females showing higher vertical loading rates during ruck marching, and peak tibial accelerations during running and ruck marching (p ≤ 0.03). Males showed higher vertical stiffness during running and peak vertical tibial accelerations during drop landings (p < 0.01). A main effect of age was found for vertical loading rates during running (p = 0.03), however no significant pairwise differences were found between age groups. These findings suggest that higher external loading may contribute to higher overall injury rates in female trainees. Further, higher stiffness during running may contribute to specific injuries, such as Achilles Tendinopathy, that are more prevalent in males. The lack of differences between age groups suggests that other factors contribute more to higher injury rates in older trainees.


Assuntos
Aceleração , Militares , Corrida , Tíbia , Humanos , Masculino , Feminino , Adulto Jovem , Fatores Etários , Fatores Sexuais , Corrida/fisiologia , Adulto , Tíbia/fisiologia , Fenômenos Biomecânicos , Estados Unidos , Caminhada/fisiologia
16.
Phys Med Biol ; 69(12)2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38648786

RESUMO

Objective.Image quality in whole-body MRI (WB-MRI) may be degraded by faulty radiofrequency (RF) coil elements or mispositioning of the coil arrays. Phantom-based quality control (QC) is used to identify broken RF coil elements but the frequency of these acquisitions is limited by scanner and staff availability. This work aimed to develop a scan-specific QC acquisition and processing pipeline to detect broken RF coil elements, which is sufficiently rapid to be added to the clinical WB-MRI protocol. The purpose of this is to improve the quality of WB-MRI by reducing the number of patient examinations conducted with suboptimal equipment.Approach.A rapid acquisition (14 s additional acquisition time per imaging station) was developed that identifies broken RF coil elements by acquiring images from each individual coil element and using the integral body coil. This acquisition was added to one centre's clinical WB-MRI protocol for one year (892 examinations) to evaluate the effect of this scan-specific QC. To demonstrate applicability in multi-centre imaging trials, the technique was also implemented on scanners from three manufacturers.Main results. Over the course of the study RF coil elements were flagged as potentially broken on five occasions, with the faults confirmed in four of those cases. The method had a precision of 80% and a recall of 100% for detecting faulty RF coil elements. The coil array positioning measurements were consistent across scanners and have been used to define the expected variation in signal.Significance. The technique demonstrated here can identify faulty RF coil elements and positioning errors and is a practical addition to the clinical WB-MRI protocol. This approach was fully implemented on systems from two manufacturers and partially implemented on a third. It has potential to reduce the number of clinical examinations conducted with suboptimal hardware and improve image quality across multi-centre studies.


Assuntos
Imageamento por Ressonância Magnética , Controle de Qualidade , Imagem Corporal Total , Imageamento por Ressonância Magnética/instrumentação , Imageamento por Ressonância Magnética/normas , Humanos , Imagem Corporal Total/instrumentação , Imagens de Fantasmas , Processamento de Imagem Assistida por Computador/métodos , Ondas de Rádio
17.
Orthop J Sports Med ; 12(5): 23259671241246227, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38779133

RESUMO

Background: Bone stress injury (BSI) is a common overuse injury in active women. BSIs can be classified as high-risk (pelvis, sacrum, and femoral neck) or low-risk (tibia, fibula, and metatarsals). Risk factors for BSI include low energy availability, menstrual dysfunction, and poor bone health. Higher vertical load rates during running have been observed in women with a history of BSI. Purpose/Hypothesis: The purpose of this study was to characterize factors associated with BSI in a population of premenopausal women, comparing those with a history of high-risk or low-risk BSI with those with no history of BSI. It was hypothesized that women with a history of high-risk BSI would be more likely to exhibit lower bone mineral density (BMD) and related factors and less favorable bone microarchitecture compared with women with a history of low-risk BSI. In contrast, women with a history of low-risk BSI would have higher load rates. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Enrolled were 15 women with a history of high-risk BSI, 15 with a history of low-risk BSI, and 15 with no history of BSI. BMD for the whole body, hip, and spine was standardized using z scores on dual-energy x-ray absorptiometry. High-resolution peripheral quantitative computed tomography was used to quantify bone microarchitecture at the radius and distal tibia. Participants completed surveys characterizing factors that influence bone health-including sleep, menstrual history, and eating behaviors-utilizing the Eating Disorder Examination Questionnaire (EDE-Q). Each participant completed a biomechanical assessment using an instrumented treadmill to measure load rates before and after a run to exertion. Results: Women with a history of high-risk BSI had lower spine z scores than those with low-risk BSI (-1.04 ± 0.76 vs -0.01 ± 1.15; P < .05). Women with a history of high-risk BSI, compared with low-risk BSI and no BSI, had the highest EDE-Q subscores for Shape Concern (1.46 ± 1.28 vs 0.76 ± 0.78 and 0.43 ± 0.43) and Eating Concern (0.55 ± 0.75 vs 0.16 ± 0.38 and 0.11 ± 0.21), as well as the greatest difference between minimum and maximum weight at current height (11.3 ± 5.4 vs 7.7 ± 2.9 and 7.6 ± 3.3 kg) (P < .05 for all). Women with a history of high-risk BSI were more likely than those with no history of BSI to sleep <7 hours on average per night during the week (80% vs 33.3%; P < .05). The mean and instantaneous vertical load rates were not different between groups. Conclusion: Women with a history of high-risk BSI were more likely to exhibit risk factors for poor bone health, including lower BMD, while load rates did not distinguish women with a history of BSI.

18.
J Sci Med Sport ; 27(5): 287-292, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38383211

RESUMO

Non-steroidal anti-inflammatory drugs (NSAIDs) are frequently consumed by athletes to manage muscle soreness, expedite recovery, or improve performance. Despite the prevalence of NSAID use, their effects on muscle soreness and performance, particularly when administered prophylactically, remain unclear. This randomized, double-blind, counter-balanced, crossover study examined the effect of consuming a single dose of each of three NSAIDs (celecoxib, 200 mg; ibuprofen, 800 mg; flurbiprofen, 100 mg) or placebo 2 h before on muscle soreness and performance following an acute plyometric training session. Twelve healthy adults, aged 18-42 years, completed a standardized plyometric exercise session consisting of 10 sets of 10 repetitions at 40 % 1-repetition maximum (1RM) on a leg press device. During exercise, total work, rating of perceived exertion, and heart rate were measured. Maximum voluntary contraction force (MVC), vertical jump height, and muscle soreness were measured before exercise and 4-h and 24-h post-exercise. We found no significant differences in total work, heart rate, or rating of perceived exertion between treatments. Additionally, no significant differences in muscle soreness or vertical jump were observed between treatments. Ibuprofen and flurbiprofen did not prevent decrements in MVC, but celecoxib attenuated decreases in MVC 4-h post exercise (p < 0.05). This study suggests that athletes may not benefit from prophylactic ibuprofen or flurbiprofen treatment to prevent discomfort or performance decrements associated with exercise, but celecoxib may mitigate short-term performance decrements.


Assuntos
Anti-Inflamatórios não Esteroides , Estudos Cross-Over , Flurbiprofeno , Ibuprofeno , Mialgia , Humanos , Mialgia/prevenção & controle , Mialgia/tratamento farmacológico , Método Duplo-Cego , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/uso terapêutico , Ibuprofeno/administração & dosagem , Ibuprofeno/uso terapêutico , Adulto , Adulto Jovem , Masculino , Feminino , Flurbiprofeno/administração & dosagem , Adolescente , Desempenho Atlético/fisiologia , Celecoxib/administração & dosagem , Exercício Pliométrico , Frequência Cardíaca/efeitos dos fármacos , Exercício Físico/fisiologia
19.
Med Sci Sports Exerc ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38758530

RESUMO

PURPOSE: Optimize a dMS-based urinary proteomic technique and evaluate the relationship between urinary proteome content and adaptive changes in bone microarchitecture during BCT. METHODS: Urinary proteomes were analyzed with an optimized dMS technique in two groups of 13 recruits (n = 26) at the beginning (Pre) and end (Post) of BCT. Matched by age (21 ± 4 yr), sex (16 W), and baseline tibial trabecular bone volume fractions (Tb.BV/TV), these groups were distinguished by the most substantial (High) and minimal (Low) improvements in Tb.BV/TV. Differential protein expression was analyzed with mixed permutation ANOVA and false discovery proportion-based adjustment for multiple comparisons. RESULTS: Tibial Tb.BV/TV increased from pre- to post-BCT in High (3.30 ± 1.64%, p < 0.0001) but not Low (-0.35 ± 1.25%, p = 0.4707). The optimized dMS technique identified 10,431 peptides from 1,368 protein groups that represented 165 integrative biological processes. 74 urinary proteins changed from pre- to post-BCT (p = 0.0019) and neutrophil mediated immunity was the most prominent ontology. Two proteins (Immunoglobulin heavy constant gamma 4 and C-type lectin domain family 4 member G) differed from pre- to post-BCT in High and Low (p = 0.0006). CONCLUSIONS: The dMS technique can identify more than 1000 urinary proteins. At least 74 proteins are responsive to BCT, and other principally immune system-related proteins show differential expression patterns that coincide with adaptive bone formation.

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