Predicting football injuries using size and ratio of the multifidus and quadratus lumborum muscles.

Deficits in muscles of the lumbo-pelvic region, such as a relatively small multifidus muscle, have been used to predict lower limb injuries in professional football players. Results have been less consistent for the size of the quadratus lumborum (QL) muscle. Changes in size of the multifidus and QL muscles could be functionally related to each other, and modeling this relationship could improve prediction of lower limb injuries. Ultrasound imaging examinations were performed on male elite football players at the start of the Australian Football League (AFL) pre-season and playing season. Injury data were obtained from records collected by each club. Results indicated that the cross-sectional area of the multifidus muscle was related to the occurrence of an injury in the pre-season (odds ratio [OR] = 2.08/cm2 decrease below the mean; OR for dichotomized measure = 12.2) and in the season (OR = 2.43/cm2 ). The size of the QL muscle was significantly related to an injury in the pre-season (OR = 2.12/cm2 increase above the mean; OR for dichotomized measure = 7.26) but not in the season. A significant link was found between the ratio of the multifidus and QL muscles, and the incidence of pre-season (OR = 14.71) and season injuries (OR = 5.29). The sensitivity and specificity of the model in the pre-season were 75% and 85.7%, respectively; values for the playing season were 88.4% and 62.5%. A model was developed for prediction of lower limb injuries in football players. Combining size measurements of the multifidus and QL muscles improved predictive power. This information may have clinical implications for injury screening and prevention.

Changes in multifidus and abdominal muscle size in response to microgravity: possible implications for low back pain research.

PURPOSE: In microgravity, muscle atrophy occurs in the intrinsic muscles of the spine, with changes also observed in the abdominal muscles. Exercises are undertaken on the International Space Station and on Earth following space flight to remediate these effects. Similar effects have been seen on Earth in prolonged bed rest studies and in people with low back pain (LBP). The aim of this case report was to examine the effects of microgravity, exercise in microgravity and post-flight rehabilitation on the size of the multifidus and antero-lateral abdominal muscles. METHODS: Ultrasound imaging was used to assess size of the multifidus, transversus abdominis and internal oblique muscles at four time points: pre-flight and after daily rehabilitation on day one (R + 1), day 8 (R + 8) and day 14 (R + 14) after return to Earth (following 6 months in microgravity). RESULTS: Exercises in microgravity maintained multifidus size at L2-L4, however, after spaceflight, size of the multifidus muscle at L5 was reduced, size of the internal oblique muscle was increased and size of transversus abdominis was reduced. Rehabilitation post-space flight resulted in hypertrophy of the multifidus muscle to pre-mission size at the L5 vertebral level and restoration of antero-lateral abdominal muscle size. CONCLUSIONS: Exercise in space can prevent loss of spinal intrinsic muscle size. For the multifidus muscles, effectiveness varied at different levels of the spine. Post-mission rehabilitation targeting specific motor control restored muscle balance between the antero-lateral abdominal and multifidus muscles, similar to results from intervention trials for people with LBP. A limitation of the current investigation is that only one astronaut was studied, however, the microgravity model could be valuable as predictable effects on trunk muscles can be induced and interventions evaluated. Level of Evidence Case series.

Retraining motor control of abdominal muscles among elite cricketers with low back pain.

The purpose of this study was to document the effect of a staged stabilization training program on the motor control of the anterolateral abdominal muscles in elite cricketers with and without low back pain (LBP). Changes in the cross-sectional area of the trunk, the thickness of the internal oblique and transversus abdominis (TrA) muscles and the shortening of the TrA muscle in response to an abdominal drawing-in task were measured at the start and completion of a 13-week cricket training camp. Measures were performed using ultrasound imaging and magnetic resonance imaging. Participants from the group with LBP underwent a stabilization training program that involved performing voluntary contractions of the multifidus, TrA and pelvic floor muscles, while receiving feedback from ultrasound imaging. By the end of the training camp, the motor control of cricketers with LBP who received the stabilization training improved and was similar to that of the cricketers without LBP.

Indices of perinatal complications, family background, child rearing, and health as predictors of early cognitive and motor development.

An index of adversity is a measure of risk that can be considered independently of individual risk factors. This study examined four areas of adversity in early childhood, namely perinatal complications, family background, child-rearing practices, and the child's physical health, and their relationship to developmental outcomes. Four indices of adversity in these areas were examined as predictors of cognitive ability and motor ability for 476 girls and 510 boys at age 5 years. Results of the study indicated that indices of family background and child-rearing practices were highly related to these developmental outcomes. An index of health problems was found to be significantly related to motor ability. The perinatal complications index was significantly related only to specific cognitive ability scores for boys. Previously, developmental outcomes have been assessed in terms of the magnitude of individual risk factors, but more effective screening procedures may need to take account of the additive effect of the number of relevant adverse risk factors.

Children's exposure to smoking.

Exposure to smoking and the attitudes of other people have, in many studies, been associated with an increase in smoking through childhood and adolescence. Previous studies which have examined the relative influence of parents, siblings and friends on young people smoking do not show the same pattern of results, indicating that parents and siblings who smoke may or may not have an influence above or beyond that of friends. In this study, the extent to which these sources of exposure influence young people is examined. A related hypothesis which is tested in this study is that the amount of exposure to smoking may be a factor which influences young people to smoke independent of the particular source of the influence. The pattern of results suggests that the source of the influence is more important than the extent of influence among friends and family members. In particular, the influence of friends' smoking was evident at ages 9 to 15 years to the exclusion of the parental example of smoking. Parental smokers may lead their children to try smoking but it seems unlikely that this is related to them smoking at a later age. While peer influence may result in smoking, the influence of parents or older people smoking may be becoming a disincentive in this time of changing attitudes to smoking.

Consistency in children's recall of age of initiating smoking.

Studies of the accuracy of long-term recall for information about smoking status have tended to conclude that this information is consistent and reliable. Estimation of consumption levels have been found to be less reliable and can be influenced by current consumption levels. Results of this longitudinal study indicated that children's and adolescents' 2-year recall of smoking status was inconsistent and that children's reports of age of initiating smoking showed an unacceptably high level of misclassification, particularly if they had not smoked in the last 2 years. Children's and adolescents' 2-year recall for the age at which they first smoked were imprecise and suggested that those who had smoked in the last 2 years retained a perspective as they grew older of having started in the last few years. It is recommended that the period of recall for children and adolescents be restricted to no more than 1 year.

Sleep problems in adolescence.

A sample of 943 adolescents from the general population were questioned about sleep problems. A quarter of the sample reported needing a lot more sleep than they previously had, and 10% of the sample complained of difficulty falling asleep. Adolescents reporting sleep problems showed more anxious, depressed, inattentive, and conduct disorder behaviors than those who had no (or only occasional) sleep problems. Sleep problems, particularly multiple problems, were associated with DSM-III disorder. There were no significant differences between male and female adolescents on any of the above measures. Finally, sleep problems were relatively persistent over time from ages 13 to 15.

Prevalence and correlates of the premenstrual syndrome in adolescence.

In a longitudinal study of their health and development, 384 15-year-old females reported their experience of symptoms indicative of premenstrual syndrome (PMS). The prevalence of these symptoms is reported and a group of adolescents is identified with the syndrome (14%). PMS was associated with current self-reported anxiety, inattention, and poor health. Preadolescent self-report and maternal ratings of physical and mental health did not significantly predict adolescent PMS. The results suggest that the experience of PMS in adolescence may be mediated by perceived health status; the roles of mental health and maternal influence in the development of adolescent PMS may be minimal.

Adult physical health outcomes of adolescent girls with conduct disorder, depression, and anxiety.

OBJECTIVE: To examine the young adult physical health outcomes of adolescent girls with behavior problems. METHOD: Girls with conduct disorder, girls with depression, girls with anxiety, and healthy girls (N = 459) who had been evaluated at age 15 years were followed up at age 21, when general physical health, substance dependence, and reproductive health were assessed. RESULTS: After control for potentially confounding variables including prior health, adolescent conduct disorder predicted more medical problems, poorer self-reported overall health, lower body mass index, alcohol and/or marijuana dependence, tobacco dependence, daily smoking, more lifetime sexual partners, sexually transmitted disease, and early pregnancy. Adolescent depression predicted only adult tobacco dependence and more medical problems; adolescent anxiety predicted more medical problems. CONCLUSIONS: The robust link between female adolescent conduct disorder and poor physical health in adulthood suggests that intervention with girls who have conduct disorder may be a strategy for preventing subsequent health problems.

Identifying trajectories of adolescent smoking: an application of latent growth mixture modeling.

The goal of the current study was to identify discrete longitudinal patterns of change in adolescent smoking using latent growth mixture modeling. Five distinct longitudinal patterns were identified. A group of early rapid escalators was characterized by early escalation (at age 13) that rapidly increased to heavy smoking. A pattern characterized by occasional puffing up until age 15, at which time smoking escalated to moderate levels was also identified (late moderate escalators). Another group included adolescents who, after age 15, began to escalate slowly in their smoking to light (0.5 cigarettes per month) levels (late slow escalators). Finally, a group of stable light smokers (those who smoked 1-2 cigarettes per month) and a group of stable puffers (those who smoked only a few puffs per month) were also identified. The stable puffer group was the largest group and represented 25% of smokers.

A longitudinal study of reasons for smoking in adolescence.

This longitudinal study examined factors related to smoking at age 13 and to persistence of smoking from ages 13 to 15 years in a sample (n = 719) of New Zealand adolescents. History of smoking at 9 and 11 years predicted smoking at 13 (odds ratio = 2.8), persistence of smoking from age 13 to 15 (OR = 2.4) and smoking at 15 among those not smoking at age 13 (OR = 2.4). While there were no significant sex differences in pre-adolescent and early adolescent smoking, by age 15 more girls than boys reported smoking. A concern with the immediate negative effects of smoking (taste, smell, feeling ill and feeling silly) as a reason for not smoking at age 13 was inversely related to smoking at age 15 (OR = 0.4). Reasons for smoking at age 13 were not associated with later smoking. Family disadvantage and use of alcohol and other drugs were also associated with later adolescent smoking.

Harm reduction: roads less travelled to the holy grail.

In recent years, a number of countries have embraced harm reduction as their principal philosophical stance and policy platform on alcohol and other drug-related problems. Harm reduction, while argued by some as not being a new concept, has dramatically changed the overall orientation of many health and human service approaches. We argue that as a result many important considerations have been overlooked. This paper explores the merits of harm reduction and examines the limitations and potential pitfalls that may exist in its application in the real world. For instance, where do we position non-drug-use? Such questions are raised in light of the impression perpetuated by some leading practitioners in this field that harm reduction is a global panacea for alcohol and drug problems. Without exploring all possible paths, progress toward our holy grail of minimising the harms and maximising the potential benefits of drug use will be hampered. An integrated model is discussed, which we believe provides an opportunity for wider acceptance and ownership by alcohol and drug stakeholders, politicians and the community.

Prevalence, reliability and bias of adolescents' reports of smoking and quitting.

A follow-up of smoking behaviour to age 18 in a longitudinal study of a birth cohort enabled an assessment of the prevalence of smoking and quitting among adolescents approaching adulthood. There was a dramatic increase in number of daily smokers (15% at age 15 years to 31% at age 18 years), and in a climate of expected decreases in smoking, a history of never smoking to age 15 years was not as protective against future smoking as anticipated. Among 15-year-olds who had experimented with smoking, only 11% per year stopped by age 18 years. Cessation rates for adolescent daily smokers were low (3% had not smoked in the last year at age 18 years), and previously have not been widely reported. We also examined some methodological issues related to self-reported prevalence rates, in particular reliability, validity and sources of bias, finding confirmation of the accuracy of information from prospective longitudinal studies and supporting the conclusion that adolescents' recall for information beyond a 1-year period is inconsistent.

Psychiatric disorder in a birth cohort of young adults: prevalence, comorbidity, clinical significance, and new case incidence from ages 11 to 21.

Mental health data were gathered at ages 11, 13, 15, 18, and 21 in an epidemiological sample using standardized diagnostic assessments. Prevalence of Diagnostic and Statistical Manual of Mental Disorders (3rd ed. revised; American Psychiatric Association, 1987) mental disorders increased longitudinally from late childhood (18%) through mid-(22%) to late-adolescence (41%) and young adulthood (40%). Nearly half of age-21 cases had comorbid diagnoses; and comorbidity was associated with severity of impairment. The incidence of cases with adult onset was only 10.6%: 73.8% of adults diagnosed at age 21 had a developmental history of mental disorder. Relative to new cases, those with developmental histories were more severely impaired and more likely to have comorbid diagnoses. The high prevalence rate and significant impairment associated with a diagnosis of mental disorder suggests that treatment resources need to target the young adult sector of the population. The low new-case incidence in young adulthood, however, suggests that primary prevention and etiological research efforts need to target children and adolescents.

Is there an association between lateral preference and delinquent behavior?

Results of recent research suggests an association between left lateral preference and delinquent behavior. In this study the lateral preferences of 881 seven-year-old children were determined using behavioral indicators of hand and foot use. Mixed-handedness was associated with parent-reported problem behavior scores and self-reported delinquency scores at ages 13 and 15. However, preference for left hand and foot use was found to be unrelated to the delinquency measures. The distribution of lateral preferences in an identified delinquent group was not significantly different from the distribution in the sample remainder. The lack of an association between left preference and delinquency may be accounted for by an increased cultural acceptance of individual preference.

Adolescents' experiences of smoking cessation.

Recent prevalence rates show that by Year 10 (ages 14-16 years), 15% of students are smoking each day. As the majority of young people do not smoke, schools have traditionally provided an emphasis on prevention. However, the prevalence of daily smoking increases from 15 to 31% across the last 3 years of secondary school, suggesting a need for cessation programs. Therefore, a study of smoking cessation among students was conducted with 2877 Year 10 students in Queensland, Australia. Results of the survey showed that students (i) moderately under-estimated the number of smoking peers who had tried to stop smoking (perceived as 42%, reported as 55%), and (ii) over-estimated the success their smoking peers have (perceived as 29%, reported as 13.6%). The majority of adolescents (57.5%) reported that they had done something to influence a student not to smoke in the last 12 months, including 29% of the smokers. Among those who were current smokers, 64% wanted to stop smoking and 55% had tried to stop in the past year. Withdrawal symptoms were frequently reported among adolescent smokers and more males than females reported being stressed and depressed as a result of their efforts to quit. Intention to quit in the next year was associated with high confidence in ability to quit. These issues deserve attention in prevention programs and the development of age appropriate cessation material for adolescents should have high priority.

Beliefs about smoking cessation among out-of-school youth.

Although the majority of adolescents in the 13-18 age range are at school, there is a need to target specific groups of young smokers such as unemployed youth. For those young people who are not at school, few directed programs are available in either prevention or cessation and information is needed about the design and delivery of appropriate programs for this population. This report presents the results from a survey of unemployed youth and students at vocational colleges about various aspects of smoking cessation. The majority of out-of-school youth smokers had not tried to quit, but 52% were contemplating action to quit. Only a quarter of the smokers had quit for more than a week. Few young smokers would use a recognised program though more females would change to a lower nicotine brand, quit with the help of a friend or participate in a group quit program. The method of quitting most would recommend to peers is 'use of will power'. Incentives to quit were attractive to only a third of the smokers, and many enhancing and inhibiting factors for participation in programs were identified. In particular, efforts to quit increased their confidence in quitting, supporting the need to assist those who are contemplating action to quit. Programs need to incorporate input from youth and be tailored for them but not necessarily for different groups such as non-secondary school students and unemployed youth.

Handedness and allergic disorders in a New Zealand cohort.

Studies of the proposed association between handedness and allergic disorders have shown results which appear contradictory. In view of differences in the procedures of these studies, further tests of the strength of this association are warranted. Results from this study of a large birth cohort of children showed no support for an association between handedness measured at age 7 years and reports of eczema, urticaria, rhinitis, or asthma in late childhood or early adolescence. There was no significant association found between handedness and reported frequency and duration of symptoms of wheezing, or parental help-seeking for these symptoms. Apparent differences in the results of these studies could possibly be reconciled by the view that preference for use of the left hand may be associated with increased help-seeking behaviour in later life for a range of problems or difficulties. Further tests of the association between handedness and disorder in clinical samples require more rigorous control procedures.

Correlations between reported and measured ultraviolet radiation exposure of mothers and young children.

Cumulative and intermittent sun exposure are risk factors for skin cancer, highlighting the need to monitor exposure during childhood. There is currently very little available information concerning the accuracy of self-reported levels of sun exposure, particularly for very young children. In this study, UV radiation (UVR) exposure measured by polysulfone dosimeters worn on the wrist was compared with a measure of estimated exposure using a diary based on recall at the end of the 4 day study period and ambient dosimetric measures. Results of the study indicate that the relative UVR exposures expressed as a fraction of daily total ambient received during the 4 day period by young children and mothers are similar. A high level of association was obtained for the estimated levels of exposure between young children and their mothers. Moderate correlations were evident for dosimeter readings of mother and child on weekends with no significant association on weekdays. The association between estimated exposure and dosimeter readings was poor and needs improvement. This may be achieved by greater consideration of structural and environmental factors that influence the levels of UVR exposure received by individuals and by increasing the level of specificity in the measurement instruments. Methodological issues such as recall of exposure after several days, quantity of sun exposure and more precise measurement of grades of exposure when outside may have more impact than previously expected, and further information is being sought with a larger sample for exposure during the summer months.

Measurement of community beliefs about colorectal cancer.

Few educational campaigns have focused on bowel cancer, though studies have indicated that members of the community need and want current information about relevant issues. In order to facilitate research in this area, reliable and valid measures of community attitudes are needed. Content validity of a survey instrument was obtained through use of a Delphi process with Directors of Education from the Australia Cancer Council and focus group discussions with informed members of the public. The subsequent survey of community perceptions about colorectal cancer included a broad range of content areas related to the risk of bowel cancer, preventing and coping with bowel cancer and beliefs about susceptibility and severity. The construct validity of these content areas was investigated by use of a factor analysis and confirmation of an association with related predictor variables. Two measures related to personal influence and anticipated coping responses showed favourable psychometric properties, including moderate to high levels of internal consistency and test-retest reliability. A test of the concurrent validity of these measures requires further development of instruments related to colorectal cancer or adaptation of measures from other areas of health research.