11 resultados para Lower limbs power
em University of Queensland eSpace - Australia
Resumo:
Children bear disproportionate consequences of armed conflict. The 21st century continues to see patterns of children enmeshed in international violence between opposing combatant forces, as victims of terrorist warfare, and, perhaps most tragically of all, as victims of civil wars. Innocent children so often are the victims of high-energy wounding from military ordinance. They sustain high-energy tissue damage and massive burns - injuries that are not commonly seen in civilian populations. Children have also been deliberately targeted victims in genocidal civil wars in Africa in the past decade, and hundreds of thousands have been killed and maimed in the context of close-quarter, hand-to-hand assaults of great ferocity. Paediatricians serve as uniformed military surgeons and as civilian doctors in both international and civil wars, and have a significant strategic role to play as advocates for the rights and welfare of children in the context of the evolving 'Laws of War'. One chronic legacy of contemporary warfare is blast injury to children from landmines. Such blasts leave children without feet or lower limbs, with genital injuries, blindness and deafness. This pattern of injury has become one of the post-civil war syndromes encountered by all intensivists and surgeons serving in four of the world's continents. The continued advocacy for the international ban on the manufacture, commerce and military use of antipersonnel landmines is a part of all paediatricians' obligation to promote the ethos of the Laws of War. Post-traumatic stress disorder remains an undertreated legacy of children who have been trapped in the shot and shell of battle as well as those displaced as refugees. An urgent, unfocused and unmet challenge has been the increase in, and plight of, child soldiers themselves. A new class of combatant comprises these children, who also become enmeshed in the triad of anarchic civil war, light-weight weaponry and drug or alcohol addiction. The International Criminal Court has outlawed as a War Crime, the conscription of children under 15 years of age. Nevertheless, there remain more than 300 000 child soldiers active and enmeshed in psychopathic violence as part of both civil and international warfare. The typical profile of a child soldier is of a boy between the ages of 8 and 18 years, bonded into a group of armed peers, almost always an orphan, drug or alcohol addicted, amoral, merciless, illiterate and dangerous. Paediatricians have much to do to protect such war-enmeshed children, irrespective of the accident of their place of birth. Only by such vigorous and maintained advocacy can the world's children be better protected from the scourge of future wars.
Resumo:
The aim of this study is to review scalds occurring to children in the bathroom. The design of the study considers morbidity, risk factors, current legislation and future strategies to prevent these injuries. Forty-five patients were identified over a three-year period in a tertiary referral Children's Hospital. The median age of presentation was 14 months. The majority of injuries resulted from hot running water in the child's own bath and affected the lower limbs. Over half of the children required hospital admission. Despite recent changes in legislation, bathroom injuries still have the potential to cause significant morbidity. Their prevalence could be reduced using a combination of education and statutory regulation of water temperature in all bathrooms.
Resumo:
Objective-Although physical activity is beneficial to health, people who exercise at high intensities throughout their lifetime may have increased cardiovascular risk. Aerobic exercise increases oxidative stress and may contribute to atherogenesis by augmented oxidation of plasma lipoproteins. The aim of this study was to examine the relationship between aerobic power and markers of oxidative stress, including the susceptibility of plasma to oxidation. Methods and results-Aerobic power was measured in 24 healthy men aged 29 9 years (mean +/- SD). Plasma was analysed from subjects of high aerobic power (HAP; VO(2)max, 64.6 +/- 6.1 ml/kg/min) and lower aerobic power (LAP;VO(2)max, 45.1 +/- 6.3 ml/kg/min) for total antioxidant capacity (TAC), malondialdehyde (MDA) and susceptibility to oxidation. Three measures were used to quantify plasma oxidizability: (1) lag time to conjugated diene formation (lag time); (2) change in absorbance at 234 nm and; (3) slope of the oxidation curve during propagation (slope). The HAP subjects had significantly lowerTAC (1.38 +/- 0.04 versus 1.42 +/- 0.06 TEAC units; P < 0.05), significantly higher change in absorbance (1.55 +/- 0.21 versus 1.36 +/- 0.17 arbitrary units; P < 0.05), but no difference in MDA (P = 0.6), compared to LAP subjects. There was a significant inverse association between TAC and slope (r = -0.49; P < 0.05). Lipoprotein profiles and daily intake of nutrients did not differ between the groups. Conclusions-These findings suggest that people with high aerobic power, due to extreme endurance exercise, have plasma with decreased antioxidant capacity and higher susceptibility to oxidation, which may increase their cardiovascular risk.
Resumo:
Hormone replacement therapy (HRT) has been reported to exert a positive effect on preserving muscle strength following the menopause, however, the mechanism of action remains unclear. We examined whether the mechanism involved preservation of muscle composition as determined by skeletal muscle attenuation. Eighty women aged 50-57 years were randomly assigned to either: HRT, exercise (Ex), HRT + exercise (ExHRT), and control (Co) for 1 year. The study was double-blinded with subjects receiving oestradiol and norethisterone acetate (Kliogest) or placebo. Exercise included progressive high-impact training for the lower limbs. Skeletal muscle attenuation in Hounsfield units (HU) was determined by computed tomography of the mid-thigh. Areas examined were the quadriceps compartment (includes intermuscular adipose tissue), quadriceps muscles, the posterior compartment and posterior muscles. Muscle performance was determined by knee extensor strength, vertical jump height, and running speed over 20 m. Fifty-one women completed the intervention. Vertical jump height and running speed improved in the HRT and ExHRT groups compared with Co (interaction, P < 0.01). For both the quadriceps compartment and quadriceps muscles, HU significantly increased (interaction, P <= 0.005) for HRT, Ex, and ExHRT compared with Co. For the posterior compartment, HU for the HRT and ExHRT were significantly increased compared with Co, while for posterior muscles, ExHRT was significantly greater than Co. Although the effects were modest, the results indicate that HRT, either alone or combined with exercise, may play a role in preserving/improving skeletal muscle attenuation in early postmenopausal women and thereby exert a positive effect on muscle performance.
Resumo:
Although breathing perturbs balance, in healthy individuals little sway is detected in ground reaction forces because small movements of the spine and lower limbs compensate for the postural disturbance. When people have chronic low back pain (LBP), sway at the ground is increased, possibly as a result of reduced compensatory motion of the trunk. The aim of this study was to determine whether postural compensation for breathing is reduced during experimentally induced pain. Subjects stood on a force plate with eyes open, eyes closed, and while breathing with hypercapnoea before and after injection of hypertonic saline into the right lumbar longissimus muscle to induce LBP. Motion of the lumbar spine, pelvis, and lower limbs was measured with four inclinometers fixed over bony landmarks. During experimental pain, motion of the trunk in association with breathing was reduced. However, despite this reduction in motion, there was no increase in postural sway with breathing. These data suggest that increased body sway with breathing in people with chronic LBP is not simply because of reduced trunk movement, but instead, indicates changes in coordination by the central nervous system that are not replicated by experimental nociceptor stimulation.
Resumo:
This study has three main objectives. First, it develops a generalization of the commonly used EKS method to multilateral price comparisons. It is shown that the EKS system can be generalized so that weights can be attached to each of the link comparisons used in the EKS computations. These weights can account for differing levels of reliability of the underlying binary comparisons. Second, various reliability measures and corresponding weighting schemes are presented and their merits discussed. Finally, these new methods are applied to an international data set of manufacturing prices from the ICOP project. Although theoretically superior, it appears that the empirical impact of the weighted EKS method is generally small compared to the unweighted EKS. It is also found that this impact is larger when it is applied at lower levels of aggregation. Finally, the importance of using sector specific PPPs in assessing relative levels of manufacturing productivity is indicated.
Resumo:
Purpose: Although manufacturers of bicycle power monitoring devices SRM and Power Tap (PT) claim accuracy to within 2.5%, there are limited scientific data available in support. The purpose of this investigation was to assess the accuracy of SRM and PT under different conditions. Methods: First, 19 SRM were calibrated, raced for 11 months, and retested using a dynamic CALRIG (50-1000 W at 100 rpm). Second, using the same procedure, five PT were repeat tested on alternate days. Third, the most accurate SRM and PT were tested for the influence of cadence (60, 80, 100, 120 rpm), temperature (8 and 21degreesC) and time (1 h at similar to300 W) on accuracy. Finally, the same SRM and PT were downloaded and compared after random cadence and gear surges using the CALRIG and on a training ride. Results: The mean error scores for SRM and PT factory calibration over a range of 50-1000 W were 2.3 +/- 4.9% and -2.5 +/- 0.5%, respectively. A second set of trials provided stable results for 15 calibrated SRM after 11 months (-0.8 +/- 1.7%), and follow-up testing of all PT units confirmed these findings (-2.7 +/- 0.1%). Accuracy for SRM and PT was not largely influenced by time and cadence; however. power output readings were noticeably influenced by temperature (5.2% for SRM and 8.4% for PT). During field trials, SRM average and max power were 4.8% and 7.3% lower, respectively, compared with PT. Conclusions: When operated according to manufacturers instructions, both SRM and PT offer the coach, athlete, and sport scientist the ability to accurately monitor power output in the lab and the field. Calibration procedures matching performance tests (duration, power, cadence, and temperature) are, however, advised as the error associated with each unit may vary.
Resumo:
The distributions of eyes-closed resting electroencephalography (EEG) power spectra and their residuals were described and compared using classically averaged and adaptively aligned averaged spectra. Four minutes of eyes-closed resting EEG was available from 69 participants. Spectra were calculated with 0.5-Hz resolution and were analyzed at this level. It was shown that power in the individual 0.5 Hz frequency bins can be considered normally distributed when as few as three or four 2-second epochs of EEG are used in the average. A similar result holds for the residuals. Power at the peak Alpha frequency has quite different statistical behaviour to power at other frequencies and it is considered that power at peak Alpha represents a relatively individuated process that is best measured through aligned averaging. Previous analyses of contrasts in upper and lower alpha bands may be explained in terms of the variability or distribution of the peak Alpha frequency itself.