Malnutrition and falls risk in community-dwelling older adults

Background and Aims: Falls and fall-related injuries result in reduced functioning, loss of independence, premature nursing home admissions and mortality. Malnutrition is associated with falls in the acute setting, but little is known about malnutrition and falls risk in the community. The aim of this study was to assess the association between malnutrition risk, falls risk and falls over a one-year period in community-dwelling older adults. Methods: Two hundred and fifty four subjects >65 years of age were recruited to participate in a study in order to identify risk factors for falls. Malnutrition risk was determined using the Mini Nutritional Assessment–Short Form. Results: 28.6% had experienced a fall and according to the Mini Nutritional Assessment-Short Form 3.9% (n=10) of subjects were at risk of malnutrition. There were no associations between malnutrition risk, the risk of falls, nor actual falls in healthy older adults in the community setting. Conclusions: There was a low prevalence of malnutrition risk in this sample of community-dwelling older adults and no association between nutritional risk and falls. Screening as part of a falls prevention program should focus on the risk of developing malnutrition as this is associated with falls.

Towards an integration of the theory of planned behaviour and cognitive behavioural strategies : an example from a school-based injury prevention programme

Adolescent risk-taking behavior has potentially serious injury consequences and school-based behavior change programs provide potential for reducing such harm. A well-designed program is likely to be theory-based and ecologically valid however it is rare that the operationalisation process of theories is described. The aim of this paper is to outline how the Theory of Planned Behavior and Cognitive Behavioral Therapy informed intervention design in a school setting. Teacher interviews provided insights into strategies that might be implemented within the curriculum and provided detail used to operationalise theory constructs. Benefits and challenges in applying both theories are described with examples from an injury prevention program, Skills for Preventing Injury in Youth.

The effects of dietary fish oil on inflammation, fibrosis and oxidative stress associated with obstructive renal injury in rats.

Scope: We examined whether dietary supplementation with fish oil modulates inflammation, fibrosis and oxidative stress following obstructive renal injury. Methods and results: Three groups of Sprague-Dawley rats (n = 16 per group) were fed for 4 wk on normal rat chow (oleic acid), chow containing fish oil (33 g eicosapentaenoic acid and 26 g docosahexaenoic acid per kg diet), or chow containing safflower oil (60 g linoleic acid per kg diet). All diets contained 7% fat. After 4 wk, the rats were further subdivided into four smaller groups (n = 4 per group). Unilateral ureteral obstruction was induced in three groups (for 4, 7 and 14 days). The fourth group for each diet did not undergo surgery, and was sacrificed as controls at 14 days. When rats were sacrificed, plasma and portions of the kidneys were removed and frozen; other portions of kidney tissue were fixed and prepared for histology. Compared with normal chow and safflower oil, fish oil attenuated collagen deposition, macrophage infiltration, TGF-beta expression, apoptosis, and tissue levels of arachidonic acid, MIP-1 alpha, IL-1 beta, MCP-1 and leukotriene B(4). Compared with normal chow, fish oil increased the expression of HO-1 protein in kidney tissue. Conclusions: Fish oil intake reduced inflammation, fibrosis and oxidative stress following obstructive renal injury.

Aging and its effect on inflammation in skeletal muscle at rest and following exercise-induced muscle injury

Aging and its effects on inflammation in skeletal muscle at rest and following exercise-induced muscle injury. Am J Physiol Regul Integr Comp Physiol 298: R1485-R1495, 2010. First published April 14, 2010; doi:10.1152/ajpregu.00467.2009.-The world's elderly population is expanding rapidly, and we are now faced with the significant challenge of maintaining or improving physical activity, independence, and quality of life in the elderly. Counteracting the progressive loss of muscle mass that occurs in the elderly, known as sarcopenia, represents a major hurdle in achieving these goals. Indirect evidence for a role of inflammation in sarcopenia is that markers of systemic inflammation correlate with the loss of muscle mass and strength in the elderly. More direct evidence is that compared with skeletal muscle of young people, the number of macrophages is lower, the gene expression of several cytokines is higher, and stress signaling proteins are activated in skeletal muscle of elderly people at rest. Sarcopenia may also result from inadequate repair and chronic maladaptation following muscle injury in the elderly. Macrophage infiltration and the gene expression of certain cytokines are reduced in skeletal muscle of elderly people compared with young people following exercise-induced muscle injury. Further research is required to identify the cause(s) of inflammation in skeletal muscle of elderly people. Additional work is also needed to expand our understanding of the cells, proteins, and transcription factors that regulate inflammation in the skeletal muscle of elderly people at rest and after exercise. This knowledge is critical for devising strategies to restrict sarcopenia, and improve the health of today's elderly population.

Cytokine responses to carbohydrate ingestion during recovery from exercise-induced muscle injury.

We investigated the effect of carbohydrate ingestion after maximal lengthening contractions of the knee extensors on circulating concentrations of myocellular proteins and cytokines, and cytokine mRNA expression in muscle. Using a cross-over design, 10 healthy males completed 5 sets of 10 lengthening (eccentric) contractions (unilateral leg press) at 120% 1 repetition-maximum. Subjects were randomized to consume a carbohydrate drink (15% weight per volume; 3 g/kg BM) for 3 h after exercise using one leg, or a placebo drink after exercise using the contralateral leg on another day. Blood samples (10 mL) were collected before exercise and after 0, 30, 60, 90, 120, 150, and 180 min of recovery. Muscle biopsies (vastus lateralis) were collected before exercise and after 3 h of recovery. Following carbohydrate ingestion, serum concentrations of glucose (30-90 min and at 150 min) and insulin (30-180 min) increased (P < 0.05) above pre-exercise values. Serum myoglobin concentration increased (similar to 250%; P < 0.05) after both trials. In contrast, serum cytokine concentrations were unchanged throughout recovery in both trials. Muscle mRNA expression for IL-8 (6.4-fold), MCP-1 (4.7-fold), and IL-6 (7.3-fold) increased substantially after carbohydrate ingestion. TNF-alpha mRNA expression did not change after either trial. Carbohydrate ingestion during early recovery from exercise-induced muscle injury may promote proinflammatory reactions within skeletal muscle.

The relationship between drivers’ perceptions toward police speed enforcement and self-reported speeding behaviour

Exceeding the speed limit and driving too fast for the conditions are regularly cited as significant contributing factors in traffic crashes, particularly fatal and serious injury crashes. Despite an extensive body of research highlighting the relationship between increased vehicle speeds and crash risk and severity, speeding remains a pervasive behaviour on Australian roads. The development of effective countermeasures designed to reduce the prevalence of speeding behaviour requires that this behaviour is well understood. The primary aim of this program of research was to develop a better understanding of the influence of drivers’ perceptions and attitudes toward police speed enforcement on speeding behaviour. Study 1 employed focus group discussions with 39 licensed drivers to explore the influence of perceptions relating to specific characteristics of speed enforcement policies and practices on drivers’ attitudes towards speed enforcement. Three primary factors were identified as being most influential: site selection; visibility; and automaticity (i.e., whether the enforcement approach is automated/camera-based or manually operated). Perceptions regarding these enforcement characteristics were found to influence attitudes regarding the perceived legitimacy and transparency of speed enforcement. Moreover, misperceptions regarding speed enforcement policies and practices appeared to also have a substantial impact on attitudes toward speed enforcement, typically in a negative direction. These findings have important implications for road safety given that prior research has suggested that the effectiveness of speed enforcement approaches may be reduced if efforts are perceived by drivers as being illegitimate, such that they do little to encourage voluntary compliance. Study 1 also examined the impact of speed enforcement approaches varying in the degree of visibility and automaticity on self-reported willingness to comply with speed limits. These discussions suggested that all of the examined speed enforcement approaches (see Section 1.5 for more details) generally showed potential to reduce vehicle speeds and encourage compliance with posted speed limits. Nonetheless, participant responses suggested a greater willingness to comply with approaches operated in a highly visible manner, irrespective of the corresponding level of automaticity of the approach. While less visible approaches were typically associated with poorer rates of driver acceptance (e.g., perceived as “sneaky” and “unfair”), participants reported that such approaches would likely encourage long-term and network-wide impacts on their own speeding behaviour, as a function of the increased unpredictability of operations and increased direct (specific deterrence) and vicarious (general deterrence) experiences with punishment. Participants in Study 1 suggested that automated approaches, particularly when operated in a highly visible manner, do little to encourage compliance with speed limits except in the immediate vicinity of the enforcement location. While speed cameras have been criticised on such grounds in the past, such approaches can still have substantial road safety benefits if implemented in high-risk settings. Moreover, site-learning effects associated with automated approaches can also be argued to be a beneficial by-product of enforcement, such that behavioural modifications are achieved even in the absence of actual enforcement. Conversely, manually operated approaches were reported to be associated with more network-wide impacts on behaviour. In addition, the reported acceptance of such methods was high, due to the increased swiftness of punishment, ability for additional illegal driving behaviours to be policed and the salutary influence associated with increased face-to-face contact with authority. Study 2 involved a quantitative survey conducted with 718 licensed Queensland drivers from metropolitan and regional areas. The survey sought to further examine the influence of the visibility and automaticity of operations on self-reported likelihood and duration of compliance. Overall, the results from Study 2 corroborated those of Study 1. All examined approaches were again found to encourage compliance with speed limits, such that all approaches could be considered to be “effective”. Nonetheless, significantly greater self-reported likelihood and duration of compliance was associated with visibly operated approaches, irrespective of the corresponding automaticity of the approach. In addition, the impact of automaticity was influenced by visibility; such that significantly greater self-reported likelihood of compliance was associated with manually operated approaches, but only when they are operated in a less visible fashion. Conversely, manually operated approaches were associated with significantly greater durations of self-reported compliance, but only when they are operated in a highly visible manner. Taken together, the findings from Studies 1 and 2 suggest that enforcement efforts, irrespective of their visibility or automaticity, generally encourage compliance with speed limits. However, the duration of these effects on behaviour upon removal of the enforcement efforts remains questionable and represents an area where current speed enforcement practices could possibly be improved. Overall, it appears that identifying the optimal mix of enforcement operations, implementing them at a sufficient intensity and increasing the unpredictability of enforcement efforts (e.g., greater use of less visible approaches, random scheduling) are critical elements of success. Hierarchical multiple regression analyses were also performed in Study 2 to investigate the punishment-related and attitudinal constructs that influence self-reported frequency of speeding behaviour. The research was based on the theoretical framework of expanded deterrence theory, augmented with three particular attitudinal constructs. Specifically, previous research examining the influence of attitudes on speeding behaviour has typically focussed on attitudes toward speeding behaviour in general only. This research sought to more comprehensively explore the influence of attitudes by also individually measuring and analysing attitudes toward speed enforcement and attitudes toward the appropriateness of speed limits on speeding behaviour. Consistent with previous research, a number of classical and expanded deterrence theory variables were found to significantly predict self-reported frequency of speeding behaviour. Significantly greater speeding behaviour was typically reported by those participants who perceived punishment associated with speeding to be less certain, who reported more frequent use of punishment avoidance strategies and who reported greater direct experiences with punishment. A number of interesting differences in the significant predictors among males and females, as well as younger and older drivers, were reported. Specifically, classical deterrence theory variables appeared most influential on the speeding behaviour of males and younger drivers, while expanded deterrence theory constructs appeared more influential for females. These findings have important implications for the development and implementation of speeding countermeasures. Of the attitudinal factors, significantly greater self-reported frequency of speeding behaviour was reported among participants who held more favourable attitudes toward speeding and who perceived speed limits to be set inappropriately low. Disappointingly, attitudes toward speed enforcement were found to have little influence on reported speeding behaviour, over and above the other deterrence theory and attitudinal constructs. Indeed, the relationship between attitudes toward speed enforcement and self-reported speeding behaviour was completely accounted for by attitudes toward speeding. Nonetheless, the complexity of attitudes toward speed enforcement are not yet fully understood and future research should more comprehensively explore the measurement of this construct. Finally, given the wealth of evidence (both in general and emerging from this program of research) highlighting the association between punishment avoidance and speeding behaviour, Study 2 also sought to investigate the factors that influence the self-reported propensity to use punishment avoidance strategies. A standard multiple regression analysis was conducted for exploratory purposes only. The results revealed that punishment-related and attitudinal factors significantly predicted approximately one fifth of the variance in the dependent variable. The perceived ability to avoid punishment, vicarious punishment experience, vicarious punishment avoidance and attitudes toward speeding were all significant predictors. Future research should examine these relationships more thoroughly and identify additional influential factors. In summary, the current program of research has a number of implications for road safety and speed enforcement policy and practice decision-making. The research highlights a number of potential avenues for the improvement of public education regarding enforcement efforts and provides a number of insights into punishment avoidance behaviours. In addition, the research adds strength to the argument that enforcement approaches should not only demonstrate effectiveness in achieving key road safety objectives, such as reduced vehicle speeds and associated crashes, but also strive to be transparent and legitimate, such that voluntary compliance is encouraged. A number of potential strategies are discussed (e.g., point-to-point speed cameras, intelligent speed adaptation. The correct mix and intensity of enforcement approaches appears critical for achieving optimum effectiveness from enforcement efforts, as well as enhancements in the unpredictability of operations and swiftness of punishment. Achievement of these goals should increase both the general and specific deterrent effects associated with enforcement through an increased perceived risk of detection and a more balanced exposure to punishment and punishment avoidance experiences.

A qualitative investigation of older pedestrian views of influences on their road crossing safety

With Australia’s population rapidly ageing, older pedestrian safety has begun to receive greater attention from road safety researchers. However, reliance on simulator studies and observational techniques has limited current understanding of why older pedestrians adopt particular crossing behaviours, and how they perceive crossing the road. The current study aimed to investigate the psychological factors that may contribute to older pedestrians’ crash risk by examining their perceptions of the issues they encounter on the road. Qualitative semi-structured interviews with 18 pedestrians aged 55 years and older were conducted, and the interview transcripts underwent thematic analysis. From this analysis, four key themes emerged. Firstly, the physical design of the road was perceived as posing a significant threat for older pedestrians, particularly sloped, semi-mountable kerbs and designated crossings. Secondly, declines in older pedestrians’ confidence in their ability to cross the road were evident through fewer reported risks being taken. Additionally, older pedestrians sensed an increased threat from other road users when crossing the road, particularly from drivers and cyclists. Finally, older pedestrians referred to the informal rules and strategies used to guide their road crossing. The results suggest that the road environment is perceived as increasingly dangerous and hazardous environment for older pedestrians. Implications regarding the physical road design in areas with an existing high proportion of elderly people are discussed.

Barriers and facilitators to diabetes self-management: Perspectives of older community dwellers and health professionals in China

Little is known about self-management among people with Type 2 diabetes living in mainland China. Understanding the experiences of this target population is needed to provide socioculturally relevant education to effectively promote self-management. The aim of this study was to explore perceived barriers and facilitators to diabetes self-management from both older community dwellers and health professionals in China. Four focus groups, two for older people with diabetes and two for health professionals, were conducted. All participants were purposively sampled from two communities in Shanghai, China. Six barriers were identified: overdependence on but dislike of western medicine, family role expectations, cuisine culture, lack of trustworthy information sources, deficits in communication between clients and health professionals, and restriction of reimbursement regulations. Facilitators included family and peer support, good relationships with health professionals, simple and practical instruction and a favourable community environment. The findings provide valuable information for diabetes self-management intervention development in China, and have implications for programmes tailored to populations in similar sociocultural circumstance.

Transport injury risks in Queensland adolescents of Pacific Islander descent

Ethnicity is rarely considered in the development of injury prevention programs, despite its known impact on participation in risk behaviour. This study sought to understand engagement in transport related risk behaviours, patterns of injury and perceptions of risk among early adolescents who self-identify as being from a Pacific Islander background. In total 5 high schools throughout Queensland, Australia were recruited, of which 498 Year 9 students (13-14 years) completed questionnaires relating to their perceptions of risk and recent injury experience (specifically those transport behaviours that were medically treated and those that were not medically treated). The transport related risk behaviours captured in the survey were bicycle use, motorcycle use and passenger safety (riding with a drink driver and riding with a dangerous driver). The results are explored in terms of the prevalence of engagement in risky transport related behaviour among adolescents’ of Pacific Islander background compared to others of the same age. The results of this study provide an initial insight into the target participants’ perspective of risk in a road safety context as well as their experience of such behaviour and related injuries. This information may benefit future intervention programs specific to adolescents’ of Pacific Islander background.

Evaluation of screening tests for predicting older driver performance and safety assessed by an on-road test

A number of tests and test batteries are available for the prediction of older driver safety, but many of these have not been validated against standardized driving outcome measures. The aim of this study was to evaluate a series of previously described screening tests in terms of their ability to predict the potential for safe and unsafe driving. Participants included 79 community-dwelling older drivers (M=72.16 years, SD=5.46; range 65-88 years; 57 males and 22 females) who completed a previously validated multi-disciplinary driving assessment, a hazard perception test, a hazard change detection test and a battery of vision and cognitive tests. Participants also completed a standardized on-road driving assessment. The multi-disciplinary test battery had the highest predictive ability with a sensitivity of 80% and a specificity of 73%, followed by the hazard perception test which demonstrated a sensitivity of 75% and a specificity of 61%. These findings suggest that a relatively simple and practical battery of tests from a range of domains has the capacity to predict safe and unsafe driving in older adults.

The role of neuromuscular inhibition in hamstring strain injury recurrence

Hamstring strain injuries are amongst the most common and problematic injuries in a wide range of sports that involve high speed running. The comparatively high rate of hamstring injury recurrence is arguably the most concerning aspect of these injuries. A number of modifiable and nonmodifiable risk factors are proposed to predispose athletes to hamstring strains. Potentially, the persistence of risk factors and the development of maladaptations following injury may explain injury recurrence. Here, the role of neuromuscular inhibition following injury is discussed as a potential mechanism for several maladaptations associated with hamstring re-injury. These maladaptations include eccentric hamstring weakness, selective hamstring atrophy and shifts in the knee flexor torque-joint angle relationship. Current evidence indicates that athletes return to competition after hamstring injury having developed maladaptations that predispose them to further injury. When rehabilitating athletes to return to competition following hamstring strain injury, the role of neuromuscular inhibition in re-injury should be considered.

Knee flexor strength and biceps femoris activation deficits following hamstring strain injury

Background: Hamstring strain injuries (HSI) are prevalent in sport and re-injury rates have been high for many years. Maladaptation following HSI are implicated in injury recurrence however nervous system function following HSI has received little attention. Aim: To determine if recreational athletes with a history of unilateral HSI, who have returned to training and competition, will exhibit lower levels of voluntary activation (VA) and median power frequency (MPF) in the previously injured limb compared to the uninjured limb at long muscle lengths. Methods: Twenty-eight recreational athletes were recruited. Of these, 13 athletes had a history of unilateral HSI and 15 had no history of HSI. Following familiarisation, all athletes undertook isokinetic dynamometry testing and surface electromyography assessment of the biceps femoris long head and medial hamstrings during concentric and eccentric contractions at ± 180 and ± 60deg/s. Results: The previously injured limb was weaker at all contraction speeds compared to the uninjured limb (+180deg/s mean difference(MD) = 9.3Nm, p = 0.0036; +60deg/s MD = 14.0Nm, p = 0.0013; -60deg/s MD = 18.3Nm, p = 0.0007; -180deg/s MD = 20.5Nm, p = 0.0007) whilst VA was only lower in the biceps femoris long head during eccentric contractions (-60deg/s MD = 0.13, p = 0.0025; -180deg/s MD = 0.13, p = 0.0003). There were no between limb differences in medial hamstring VA or MPF from either biceps femoris long head or medial hamstrings in the injured group. The uninjured group showed no between limb differences with any of the tested variables. Conclusion: Previously injured hamstrings were weaker than the contralateral uninjured hamstring at all tested speeds and contraction modes. During eccentric contractions biceps femoris long head VA was lower in the previously injured limb suggesting neural control of biceps femoris long head may be altered following HSI. Current rehabilitation practices have been unsuccessful in restoring strength and VA following HSI. Restoration of these markers should be considered when determining the success of rehabilitation from HSI. Further investigations are required to elucidate the full impact of lower levels of biceps femoris long head VA following HSI on rehabilitation outcomes and re-injury risk.

Impact of previous hamstring strain injury on rate of torque and EMG development during eccentric contraction.

Background: Hamstring strain injuries (HSIs) are prevalent in sport and re-injury rates have been high for many years. Whilst much focus has centred on the impact of previous hamstring strain injury on maximal eccentric strength, high rates of torque development is also of interest, given the important role of the hamstrings during the terminal swing phase of gait. The impact of prior strain injury on neuromuscular function of the hamstrings during tasks requiring high rates of torque development has received little attention. The purpose of this study is to determine if recreational athletes with a history of unilateral hamstring strain injury, who have returned to training and competition, will exhibit lower levels of eccentric muscle activation, rate of torque development and impulse 30, 50 and 100ms after the onset of electromyographical or torque development in the previously injured limb compared to the uninjured limb. Methods: Twenty-six recreational athletes were recruited. Of these, 13 athletes had a history of unilateral hamstring strain injury (all confined to biceps femoris long head) and 13 had no history of hamstring strain injury. Following familiarisation, all athletes undertook isokinetic dynamometry testing and surface electromyography assessment of the biceps femoris long head and medial hamstrings during eccentric contractions at -60 and -1800.s-1. Results: In the injured limb of the injured group, compared to the contralateral uninjured limb rate of torque development and impulse was lower during -600.s-1 eccentric contractions at 50 (RTD, p=0.008; IMP, p=0.005) and 100ms (RTD, p=0.001; IMP p<0.001) after the onset of contraction. There was also a non-significant trend for rate of torque development during -1800.s-1 to be lower 100ms after onset of contraction (p=0.064). Biceps femoris long head muscle activation was lower at 100ms at both contraction speeds (-600.s-1, p=0.009; -1800.s-1, p=0.009). Medial hamstring activation did not differ between limbs in the injured group. Comparisons in the uninjured group showed no significant between limbs difference for any variables. Conclusion: Previously injured hamstrings displayed lower rate of torque development and impulse during eccentric contraction. Lower muscle activation was confined to the biceps femoris long head. Regardless of whether these deficits are the cause of or the result of injury, these findings have important implications for hamstring strain injury and re-injury and suggest greater attention be given to neural function of the knee flexors.