Single-subject analysis reveals varied knee mechanics during step landing in response to isokinetic fatigue of the quadriceps

Introduction: The ability to regulate joint stiffness and coordinate movement during landing when impaired by muscle fatigue has important implications for knee function. Unfortunately, the literature examining fatigue effects on landing mechanics suffers from a lack of consensus. Inconsistent results can be attributed to variable fatigue models, as well as grouping variable responses between individuals when statistically detecting differences between conditions. There remains a need to examine fatigue effects on knee function during landing with attention to these methodological limitations. Aim: The purpose of this study therefore, was to examine the effects of isokinetic fatigue on pre-impact muscle activity and post-impact knee mechanics during landing using singlesubject analysis. Methodology: Sixteen male university students (22.6+3.2 yrs; 1.78+0.07 m; 75.7+6.3 kg) performed maximal concentric and eccentric knee extensions in a reciprocal manner on an isokinetic dynamometer and step-landing trials on 2 occasions. On the first occasion each participant performed 20 step-landing trials from a knee-high platform followed by 75 maximal contractions on the isokinetic dynamometer. The isokinetic data was used to calculate the operational definition of fatigue. On the second occasion, with a minimum rest of 14 days, participants performed 2 sets of 20 step landing trials, followed by isokinetic exercise until the operational definition of fatigue was met and a final post-fatigue set of 20 step-landing trials. Results: Single-subject analyses revealed that isokinetic fatigue of the quadriceps induced variable responses in pre impact activation of knee extensors and flexors (frequency, onset timing and amplitude) and post-impact knee mechanics(stiffness and coordination). In general however, isokinetic fatigue induced sig nificant (p<0.05) reductions in quadriceps activation frequency, delayed onset and increased amplitude. In addition, knee stiffness was significantly (p<0.05) increased in some individuals, as well as impaired sagittal coordination. Conclusions: Pre impact activation and post-impact mechanics were adjusted in patterns that were unique to the individual, which could not be identified using traditional group-based statistical analysis. The results suggested that individuals optimised knee function differently to satisfy competing demands, such as minimising energy expenditure, as well as maximising joint stability and sensory information.

Single-subject analysis reveals variation in knee mechanics during step landing

Introduction: Evidence concerning the alteration of knee function during landing suffers from a lack of consensus. This uncertainty can be attributed to methodological flaws, particularly in relation to the statistical analysis of variable human movement data. Aim: The aim of this study was to compare single-subject and group analysis in quantifying alterations in the magnitude and within-participant variability of knee mechanics during a step landing task. Methods: A group of healthy men (N = 12) stepped-down from a knee-high platform for 60 consecutive trials, each trial separated by a 1-minute rest. The magnitude and within-participant variability of sagittal knee stiffness and coordination of the landing leg during the immediate postimpact period were evaluated. Coordination of the knee was quantified in the sagittal plane by calculating the mean absolute relative phase of sagittal shank and thigh motion (MARP1) and between knee rotation and knee flexion (MARP2). Changes across trials were compared between both group and single-subject statistical analyses. Results: The group analysis detected significant reductions in MARP1 magnitude. However, the single-subject analyses detected changes in all dependent variables, which included increases in variability with task repetition. Between-individual variation was also present in the timing, size and direction of alterations to task repetition. Conclusion: The results have important implications for the interpretation of existing information regarding the adaptation of knee mechanics to interventions such as fatigue, footwear or landing height. It is proposed that a familiarisation session be incorporated in future experiments on a single-subject basis prior to an intervention.

Impact of opening a new emergency department on healthcare service and patient outcomes : analyses based on linking ambulance, emergency and hospital databases

Background Emergency department (ED) crowding caused by access block is an increasing public health issue and has been associated with impaired healthcare delivery, negative patient outcomes and increased staff workload. Aim To investigate the impact of opening a new ED on patient and healthcare service outcomes. Methods A 24-month time series analysis was employed using deterministically linked data from the ambulance service and three ED and hospital admission databases in Queensland, Australia. Results Total volume of ED presentations increased 18%, while local population growth increased by 3%. Healthcare service and patient outcomes at the two pre-existing hospitals did not improve. These outcomes included ambulance offload time: (Hospital A PRE: 10 min, POST: 10 min, P < 0.001; Hospital B PRE: 10 min, POST: 15 min, P < 0.001); ED length of stay: (Hospital A PRE: 242 min, POST: 246 min, P < 0.001; Hospital B PRE: 182 min, POST: 210 min, P < 0.001); and access block: (Hospital A PRE: 41%, POST: 46%, P < 0.001; Hospital B PRE: 23%, POST: 40%, P < 0.001). Time series modelling indicated that the effect was worst at the hospital furthest away from the new ED. Conclusions An additional ED within the region saw an increase in the total volume of presentations at a rate far greater than local population growth, suggesting it either provided an unmet need or a shifting of activity from one sector to another. Future studies should examine patient decision making regarding reasons for presenting to a new or pre-existing ED. There is an inherent need to take a ‘whole of health service area’ approach to solve crowding issues.

Queensland Emergency Medicine Research Foundation: Special report

The development of any new profession is dependent on the development of a special body of knowledge which is the domain of the profession and key to this is the conduct of research. In 2007, as part of the settlement of an Enterprise Bargaining Agreement and following sustained lobbying by Emergency Physicians, the Queensland Government agreed to establish an Emergency Medicine Research Fund to foster the development of research activities in Emergency Medicine in Queensland. That fund is now managed by the Queensland Emergency Medicine Research Foundation. The aims of this article are to describe the strategic approaches taken by the Foundation and its first three years of experience, to describe the application of research funds and to foreshadow an evaluative framework for determining the strategic value of this community investment. The Foundation has developed a range of personnel and project support funding programs and competition for funding has increased. Ongoing evaluation will seek to determine the effectiveness of this funding strategy on improving the effectiveness of research performance and the clinical and organisational outcomes that may derive from that initiative.

Pandemic (H1N1) Influenza 2009 and Australian emergency departments : implications for policy, practice and pandemic preparedness

Objective: To describe the reported impact of Pandemic (H1N1) 2009 on EDs, so as to inform future pandemic policy, planning and response management. Methods: This study comprised an issue and theme analysis of publicly accessible literature, data from jurisdictional health departments, and data obtained from two electronic surveys of ED directors and ED staff. The issues identified formed the basis of policy analysis and evaluation. Results: Pandemic (H1N1) 2009 had a significant impact on EDs with presentation for patients with ‘influenza-like illness’ up to three times that of the same time in previous years. Staff reported a range of issues, including poor awareness of pandemic plans, patient and family aggression, chaotic information flow to themselves and the public, heightened stress related to increased workloads and lower levels of staffing due to illness, family care duties and redeployment of staff to flu clinics. Staff identified considerable discomfort associated with prolonged times wearing personal protective equipment. Staff believed that the care of non-flu patients was compromised during the pandemic as a result of overwork, distraction from core business and the difficulties associated with accommodating infectious patients in an environment that was not conducive. Conclusions: This paper describes the breadth of the impact of pandemics on ED operations. It identifies a need to address a range of industrial, management and procedural issues. In particular, there is a need for a single authoritative source of information, the re-engineering of EDs to accommodate infectious patients and organizational changes to enable rapid deployment of alternative sources of care.

Context-aware multicast protocol for emergency message dissemination in vehicular networks

Road traffic accidents can be reduced by providing early warning to drivers through wireless ad hoc networks. When a vehicle detects an event that may lead to an imminent accident, the vehicle disseminates emergency messages to alert other vehicles that may be endangered by the accident. In many existing broadcast-based dissemination schemes, emergency messages may be sent to a large number of vehicles in the area and can be propagated to only one direction. This paper presents a more efficient context aware multicast protocol that disseminates messages only to endangered vehicles that may be affected by the emergency event. The endangered vehicles can be identified by calculating the interaction among vehicles based on their motion properties. To ensure fast delivery, the dissemination follows a routing path obtained by computing a minimum delay tree. The multicast protocol uses a generalized approach that can support any arbitrary road topology. The performance of the multicast protocol is compared with existing broadcast protocols by simulating chain collision accidents on a typical highway. Simulation results show that the multicast protocol outperforms the other protocols in terms of reliability, efficiency, and latency.

Impact of a government triple zero awareness campaign on emergency department patient characteristics

Objective: To evaluate the impact of a government triple zero community awareness campaign on the characteristics of patients attending an ED. Methods: A study using Emergency Department Information System data was conducted in an adult metropolitan tertiary-referral teaching hospital in Brisbane. The three outcomes measured in the 3 month post-campaign period were arrival mode, Australasian Triage Scale and departure status. These measures reflect ambulance usage, clinical urgency and illness severity, respectively. They were compared with those in the 3 month pre-campaign period. Multivariate logistic regression models were used to investigate the impacts of the campaign on each of the three outcome measures after controlling for age, sex, day and time of arrival, and daily minimum temperature. Results: There were 17 920 visits in the pre- and 17 793 visits in the post-campaign period. After the campaign, fewer patients arrived at the ED by road ambulance (odds ratio [OR] 0.90, 95% confidence interval [CI] 0.80–1.00), although the impact of the campaign on the arrival mode was only close to statistical significance (Wald χ2-test, P= 0.055); and patients were significantly less likely to have higher clinical urgency (OR 0.86, 95% CI 0.79–0.94), while more likely to be admitted (OR 1.68, 95% CI 1.38–2.05) or complete treatment in the ED (OR 1.46, 95% CI 1.23–1.73) instead of leaving without waiting to be seen. Conclusions: The campaign had no significant impact on the arrival mode of the patients. After the campaign, the illness acuity of the patients decreased, whereas the illness severity of the patients increased.

What do emergency physicians think of law?

What do emergency physicians think of law? Do they know the law? What role does it have in the practice of emergency medicine? Emergency physicians in New South Wales, Victoria and Queensland are being asked about these issues in a study by the Queensland University of Technology, Brisbane, Australia, titled ‘Withholding and withdrawing life-sustaining treatment from adults who lack capacity: The role of law in medical practice’. The study aims to examine the role that law plays in decisions to withhold or withdraw life-sustaining treatment from adults who lack capacity.

Extracting deck trend to plan descent trajectory for safe landing of UAVs

This paper outlines a feasible scheme to extract deck trend when a rotary-wing unmanned aerial vehicle (RUAV)approaches an oscillating deck. An extended Kalman filter (EKF) is de- veloped to fuse measurements from multiple sensors for effective estimation of the unknown deck heave motion. Also, a recursive Prony Analysis (PA) procedure is proposed to implement online curve-fitting of the estimated heave mo- tion. The proposed PA constructs an appropriate model with parameters identified using the forgetting factor recursive least square (FFRLS)method. The deck trend is then extracted by separating dominant modes. Performance of the proposed procedure is evaluated using real ship motion data, and simulation results justify the suitability of the proposed method into safe landing of RUAVs operating in a maritime environment.

Acuity and severity of patients attending 28 Queensland hospitals emergency departments in 2008-09

Overcrowding of hospital Emergency Departments (EDs) in Australia is a complex issue of high public and professional prominence, resulted from a combination of increasing demands, increased complexity of care and Access Block. The aim of this study is to describe the distribution of the acuity and severity of current Queensland ED patients to better understand ED users...

Emergency department in hospitals, a window of the world : a preliminary comparison between Australia and China

BACKGROUND: This study aimed to make a preliminary comparison of emergency department (ED) presentations between Australia and China. The comparison could provide insights into the health systems and burden of diseases and potentially stimulate discussion about the development of acute health system in China. METHODS: An observational study was performed to compare Australian ED presentations using data obtained from a single adult tertiary-referral teaching hospital in metropolitan Brisbane against Chinese ED presentations using public domain information published in existing Chinese and international medical journals. RESULTS: There are major differences in ED presentations between Australia and China. In 2008, 1) 35.4% of patients arrived at a tertiary teaching hospital ED in Brisbane, Australia by ambulance; 2) 1.7% were treated for poisoning; 3) 1.4% for cerebral vascular disease; 4) 1.7% for cardiac disease; and 5) 42.6% for trauma. The top events diagnosed were mental health problems including general psychiatric examination, psychiatric review, alcohol abuse, and counselling for alcohol abuse, which accounted for 5.5% of all ED presentations. Among ED patients in China, 6.7% arrived at a tertiary teaching hospital by ambulance in Shenyang in 1997; 3.7% were treated for poisoning in Shanxi Zhouzhi County People's Hospital ED in 2006; 14.9% for cerebral vascular diseases at Qinghai People's Hospital ED in 1993-1995; 1.7% for cardiac diseases at the Second People's Hospital ED, Shenzhen Longgang in 1993; and 44.3% for trauma at Shanxi Zhouzhi County People's Hospital ED in 2006. The top events were trauma and poisoning among the young and cerebral infarction in the older population. CONCLUSIONS: Compared with Australian, Chinese ED patients had 1) lower ambulance usage; 2) higher proportion of poisoning; 3) higher proportion of cerebral vascular diseases; 4) similar proportion of cardiac disease; 5) similar proportion of trauma; and 6) little reported mental health problems. Possible explanations for these differences in China include a pay for service pre-hospital care system, lack of public awareness about poisons, inadequate hypertension management, and lack of recognition of mental health problems.

Emergency Health Services (EHS) : demand and service delivery models. [Monograph 2 : Queensland EHS users’ profile]

Emergency health is a critical component of Australia’s health system and one which is increasingly congested from growing demand and blocked access to inpatient beds. The Emergency Health Services Queensland (EHSQ) study aims to identify the factors driving increased demand for emergency health and to evaluate strategies which may safely reduce the future demand growth. This monograph addresses the characteristics of users of emergency health services with an aim to identify those that appear to contribute to demand growth. This study utilises data on patients treated by Emergency Departments (ED) and Queensland Ambulance Service (QAS) across Queensland. ED data was derived from the Emergency Department Information System (EDIS) for the period 2001-02 through to 2010-11. Ambulance data was extracted from the QAS’ Ambulance Information Management System (AIMS) and electronic Ambulance Report Form (eARF) for the period 2001-02 through to 2009-10. Due to discrepancies and comparability issues for ED data, this monograph compares data from the 2003-04 time period with 2010-11 data for 21 of the reporting EDs. Also a snapshot of users for the 2010-11 financial year for 31 reporting EDs is used to describe the characteristics of users and to compare those characteristics with population demographics. For QAS data, the 2002-03 and 2009-10 time periods were selected for detailed analyses to identify trends. • Demand for emergency health care services is increasing, representing both increased population and increased relative utilisation. Per capita demand for ED attention has increased by 2% per annum over the last decade and for ambulance attention by 3.7% per annum. • The growth in ED demand is prominent in more urgent triage categories with actual decline in less urgent patients. An estimated 55% of patients attend hospital EDs outside of normal working hours. There is no evidence that patients presenting out of hours are significantly different to those presenting within working hours; they have similar triage assessments and outcomes. • Patients suffering from injuries and poisoning comprise 28% of the ED workload (an increase of 65% in the study period), whilst declines of 32% in cardiovascular and circulatory conditions, and musculoskeletal problems have been observed. • 25.6% of patients attending EDs are admitted to hospital. 19% of admitted patients and 7% of patients who die in the ED are triage category 4 or 5 on arrival. • The average age of ED patients is 35.6 years. Demand has grown in all age groups and amongst both men and women. Men have higher utilisation rates for ED in all age groups. The only group where the growth rate in women has exceeded men is in the 20-29 age group; this growth is particularly in the injury and poisoning categories. • Considerable attention has been paid publicly to ED performance criteria. It is worth noting that 50% of all patients were treated within 33 minutes of arrival. • Patients from lower socioeconomic areas appear to have higher utilisation rates and the utilisation rate for indigenous people appears to exceed those of European and other backgrounds. The utilisation rates for immigrant people is generally less than that of Australian born however it has not been possible to eliminate the confounding impact of different age and socioeconomic profiles. • Demand for ambulance service is also increasing at a rate that exceeds population growth. Utilisation rates have increased by an average of 5% per annum in Queensland compared to 3.6% nationally, and the utilisation rate in Queensland is 27% higher than the national average. • The growth in ambulance utilisation has also been amongst the more urgent categories of dispatch and utilisation rates are higher in rural and regional areas than in the metropolitan area. The demand for ambulance increases with age but the growth in demand for ambulance service has been more prominent in younger age groups. These findings contribute significantly to an understanding of the growth in demand for emergency health. It shows that the growth is amongst patients in genuine need of emergency healthcare and public rhetoric that the congestion of emergency health services is due to inappropriate attendees is unable to be substantiated. The consistency of the growth in demand over the last decade reflects not only the changing demographics of the Australian population but also the changes in health status, standards of acute health care and other social factors. The growth is also amongst patients with acute injury and poisoning which is inconsistent with rates of chronic disease as a fundamental driver. We have also interviewed patients in regard to their decision making choices for acute health care and the factors that influence these decisions and this will be the subject of a third Monograph and publications.

Immigrants and the utilization of hospital emergency departments

BACKGROUND: Immigrants with language barriers are at high risk of having poor access to health care services. However, several studies have indicated that immigrants tend to use emergency departments (EDs) as their primary source of care at the expense of primary care. This may place an additional burden on already overcrowded EDs and lead to a low level of patient satisfaction with ED care. The study was to review if immigrants utilize ED care differently from host populations and to assess immigrants’ satisfaction with ED care. DATA SOURCES: Studies about immigrants' utilization of EDs in Australia and worldwide were reviewed. RESULTS: There are confl icting results in the literature about the pattern of ED care use among immigrants. Some studies have shown higher utilization by immigrants compared to host populations and others have shown lower utilization. Overall, immigrants use ED care heavily, make inappropriate visits to EDs, have a longer length of stay in EDs, and are less satisfi ed with ED care as compared to host populations. CONCLUSIONS: Immigrants might use ED care differently from host populations due to language and cultural barriers. There is sparse Australian literature regarding immigrants' access to health care including ED care. To ensure equity, further research is needed to inform policy when planning health care provision to immigrants. KEY WORDS: Emergency department; Health service; Immigrants; Language; Utilization