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.

Consistency in size and asymmetry of the psoas major muscle among elite footballers.

OBJECTIVE: To determine, using magnetic resonance imaging (MRI), the cross-sectional area (CSA) of the psoas major (PM) muscle across multiple vertebral levels, to examine any asymmetry of the PM muscle and investigate the consistency across vertebral levels, and to determine whether a relationship exists between low back pain (LBP) and the size or asymmetry of the PM muscle among elite Australian Rules football (AFL) players. DESIGN: Observational cross-sectional study. SETTING: Assessments and MRI examinations were carried out in a hospital setting. PARTICIPANTS: Thirty-one male elite AFL players aged between 20 and 32 years participated in the study. RISK FACTORS: The independent factors in the study were "asymmetry" (coded as ipsilateral or contralateral to kicking leg) and "group" (current LBP versus no current LBP). MAIN OUTCOME MEASUREMENTS: The dependent variable in the study was the CSA of the PM muscle. RESULTS: The PM muscle was larger on the side of the dominant kicking leg at all four vertebral levels measured (F = 7.28, p = 0.012). Participants who reported current LBP had larger PM muscles than the remainder of the players (F = 4.63, p = 0.041). CONCLUSION: Additional investigation into the underlying mechanisms of the observed differences in PM muscle size could help to develop treatment and rehabilitation programmes aimed at reducing the incidence of LBP among AFL players. Furthermore, asymmetry of the PM muscle was observed at multiple vertebral levels and therefore future studies may only need to take single-level measurements to assess for asymmetry.

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.

Psoas and quadratus lumborum muscle asymmetry among elite Australian Football League players.

OBJECTIVE: In this study, asymmetry relative to the preferred kicking leg was determined if it exists for the psoas and quadratus lumborum muscles among elite Australian Football League (AFL) players. DESIGN: AFL players were assessed at three time points from 2005 to 2007 (start of preseason, end of season and end of preseason training). MRI was used to determine the cross-sectional areas (CSAs) of the psoas and quadratus lumborum muscles at the L4-L5 vertebral level (psoas) and the L3-L4 vertebral level (quadratus lumborum). SETTING: MRI was performed in a hospital setting. PARTICIPANTS: 54 professional AFL players were eligible to participate in this study. The number of subjects at each of the three time points was 36 for time 1 (T1 Nov 2005), 31 for time 2 (T2 Aug 2006) and 43 for time 3 (T3 Feb Mar 2007). RISK FACTORS: The repeated measures factor in the analyses was "asymmetry", defined as "ipsilateral" or "contralateral" to preferred kicking leg. Number of injuries (coded as 0, 1, 2 or more) was also included as a risk factor. MAIN OUTCOME MEASUREMENTS: The dependent variables were the CSAs of the psoas and quadratus lumborum muscles. RESULTS: At all three time points, the CSA of the psoas muscle was significantly greater ipsilateral to the kicking leg, while the CSA of the quadratus lumborum muscle was significantly greater on the side contralateral to the kicking leg. Asymmetry in muscle size was not related to number of injuries. CONCLUSIONS: Asymmetry of the psoas and the quadratus lumborum muscles exists in elite AFL players.

MRI study of the size, symmetry and function of the trunk muscles among elite cricketers with and without low back pain.

OBJECTIVES: To determine if asymmetry of trunk muscles and deficits of motor control exist among elite cricketers with and without low back pain (LBP). DESIGN: Single-blinded observational quasi-experimental design study SETTING: Assessments were conducted in a hospital setting. PARTICIPANTS: Among a total eligible sample of 26 male elite cricketers (mean age 21.2 (SD 2.0) years), selected to attend a national training camp, 21 participated in the study. RISK FACTORS: The independent variables were 'group' (LBP or asymptomatic) and 'cricket position' (fast bowler versus the rest of the squad). MAIN OUTCOME MEASUREMENTS: The dependent variables were the cross-sectional areas (CSA) of the quadratus lumborum (QL), lumbar erector spinae plus multifidus (LES + M) and psoas muscles, the thickness of the internal oblique (IO) and transversus abdominis (TrA) muscles, and the amount of lateral slide of the anterior abdominal fascia. RESULTS: The QL and LES + M muscles were larger ipsilateral to the dominant arm. In the subgroup of fast bowlers with LBP, the asymmetry in the QL muscle was the greatest. The IO muscle was larger on the side contralateral to the dominant arm. No difference between sides was found for the psoas and TrA muscles. Cricketers with LBP showed a reduced ability to draw in the abdominal wall and contract the TrA muscle independently of the other abdominal muscles. CONCLUSIONS: This study provides new insights into trunk muscle size and function in elite cricketers, and evidence of impaired motor control in elite cricketers with LBP. Rehabilitation using a motor control approach has been shown to be effective for subjects with LBP, and this may also benefit elite cricketers.

Predictors of responsiveness to physiotherapy management of cervicogenic headache.

A recent randomized controlled trial tested the effectiveness of therapeutic exercise and manipulative therapy on 200 subjects with cervicogenic headache. Although treatments were efficacious, 25% of patients did not achieve a clinically acceptable outcome--50% reduction in headache frequency. This study aimed to identify predictors from variables in subjects' demographics and headache history which might identify those who did or did not achieve a 50-79% or 80-100% reduction in headache immediately after the active treatments and 12 months postintervention. The results revealed no consistent pattern of predictors, although the absence of light-headedness indicated higher odds of achieving either a 50-79% [odds ratio (OR) = 5.45) or 80-100% (OR = 5.7) reduction in headache frequency in the long term. Headaches of at least moderate intensity, the patient's age and chronicity of headache did not mitigate against a successful outcome from physiotherapy intervention.

Lumbo-pelvic joint protection against antigravity forces: motor control and segmental stiffness assessed with magnetic resonance imaging.

The antigravity muscles of the lumbo-pelvic region, especially transversus abdominis (TrA), are important for the protection and support of the weightbearing joints. Measures of TrA function (the response to the postural cue of drawing in the abdominal wall) have been developed and quantified using magnetic resonance imaging (MRI). Cross-sections through the trunk allowed muscle contraction as well as the large fascial attachments of the TrA to be visualized. The cross sectional area (CSA) of the deep musculo-fascial system was measured at rest and in the contracted state, using static images as well as a cine sequence. In this developmental study, MRI measures were undertaken on a small sample of low back pain (LBP) and non LBP subjects. Results demonstrated that, in non LBP subjects, the draw in action produced a symmetrical deep musculo-fascial "corset" which encircles the abdomen. This study demonstrated a difference in this "corset" measure between subjects with and without LBP. These measures may also prove useful to quantify the effect of unloading in bedrest and microgravity exposure.

Cervicogenic headache: locus of control and success of treatment.

BACKGROUND: A number of extraneous factors have been implicated in the effectiveness of treatment of headache, including patient beliefs about aspects of the treatment or persons delivering the treatment. OBJECTIVE: The concept of external locus of control for headaches refers to patients with a high level of belief that headache and relief are influenced primarily by health care professionals. The aim of this study was to examine whether external locus of control is associated with a reduction in frequency of cervicogenic headaches among patients treated by a physiotherapist. DESIGN: A recent randomized controlled trial of the effectiveness of physiotherapy among 200 patients with headache enabled a test of this relationship. Treatment consisted of manipulative therapy, therapeutic exercise, or a combination of the 2. Analysis of relative change in headache frequency was conducted after 6 weeks of treatment and at 3- and 12-month follow-up appointments. RESULTS: Results of the analysis indicated that participants with relatively high external Headache-Specific Locus of Control scores were more likely to achieve a reduction in headache frequency if they received the combined manipulative therapy and exercise therapy, compared with those who received no treatment. This was not determined for the group who received manipulative therapy, which is a treatment received passively by the patient. CONCLUSIONS: The interpretation of these findings is considered in the context of nongeneralization to the other physiotherapy treatment groups and sustained reduction in headache frequency following withdrawal of treatment. The pattern of findings suggests that characteristics of the therapy were more pertinent than characteristics of the therapist.

Behavior of caregivers to protect their infants from exposure to the sun in Queensland, Australia.

Exposure to the sun by infants has been demonstrated to increase the risk of the development of melanoma and other skin cancers later in life. A cohort of 508 women who delivered healthy Caucasian babies were followed up at 1 year to determine their knowledge, attitudes and practices regarding sun protection towards themselves and their child. In addition, the 1-year-old infants were assessed by a trained nurse for the number of nevi they had on their skin. Results indicate caregivers reported a high level of sun-protection practices towards their child, with 93% of the caregivers reporting usually or always placing the child in the shade when going outside. Further, 81% of the caregivers reported usually or always placing a hat on the child, while 64% reported usually or always applying sunscreen to the child's exposed skin. Interestingly, only 61% of the caregivers reported that they stayed in the shade to reduce sun exposure and only 42% wore a hat when out in the sun. Mother's own personal sun-protection methods predicted the method of sun protection that she would most likely use for the child. While children appear to be reasonably protected from the sun, they are influenced by their mother's own behaviors.

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.

Sun-safe behaviour among secondary school students in Australia.

This paper reports data on the first national survey of sun-protection measures of Australian secondary school students. A cross-sectional survey of a representative sample of 23,915 Australian school children in Years 7-12 was conducted in 1993. Students were questioned about usual sun-protection practices, beliefs about skin cancer and suntans, and sunburn history. The results showed differences in sun-protection behaviours as a function of 'year level', 'gender', 'skin type' and 'concern about getting cancer' among others. Adolescents who believe there is a lot they can do to avoid skin cancer are more likely to engage in sun-protective behaviours. Males were more likely to wear a cap, yet females tended to use sunscreen. The use of clothing to protect themselves from the sun was higher in males, yet females were more likely to stay mainly in the shade. All behaviours decreased with age. Poorer protective practices were also associated with increased sunburn, except for sunscreen use where the converse was the case. Suntan was still a desire for adolescents. While there is considerable room for improvement in the sun-protection behaviour of adolescents (particularly those in higher grades), most students usually take some precautions. However, by Year 12 (17 and 18 year olds) less than half report usually wearing a hat and just two-thirds reported usual sunscreen usage.

A measure of skin familiarity and its role in the early detection of skin cancer.

Skin self-examination (SSE) is promoted widely so that individuals will become familiar with their skin and be better able to identify suspicious changes earlier. However, individuals can also become familiar with their skin other than through purposeful SSE. In this article, we develop a measure of skin familiarity based on the density of spots on 14 different areas of the body. A factor analysis of the 14 body-area scores revealed that they could be grouped into four broad body regions (shoulders and back, front of legs, back of legs, and feet). Each total body score and body-region score has high internal consistency (Cronbach's alpha coefficients ranging from 0.79 to 0.93). Moreover, the scores correlate as expected with skin self-examination behaviors and other personal characteristics, indicating high construct validity. We consider the advantages that skin familiarity measures offer over the exclusive use of SSE measures in the assessment of early detection activities and discuss the direction of future research in this area.

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.

Sun exposure and primary prevention of skin cancer for infants and young children during autumn/winter.

OBJECTIVE AND METHOD: Excessive sun exposure in childhood has been associated with the development of skin cancer, and appropriate levels of sun protection during the early years of a child's life can significantly reduce the risks. A survey of 133 mothers was undertaken in south-east Queensland to examine the levels of sun exposure and skin protection of infants and young children. RESULTS: Among this sample of 133 mothers, use of appropriate skin protection was relatively high for themselves and their children. However, even by six months of age, a third had been sunburnt and 15% had experienced painful sunburn. By three years of age, 82% had been sunburnt and one-third had experienced painful sunburn, though mothers' knowledge levels of sun safety issues were very high. The predictors associated with primary prevention varied across the type of prevention behaviour, but indicated that interventions should focus on susceptibility to sunburn and history of sunburn. Similar programs could be applicable across a broad range of socio-demographic groups, but require attention to mother's country of birth as a factor that significantly influences their use of protection for their young children. CONCLUSIONS: Ongoing public education that targets specific groups and settings may contribute to adoption of appropriate sun protective behaviours for young children. IMPLICATIONS: Results of the study provide some of the needed baseline data to assist future skin cancer prevention campaigns for young children and infants. A similar study of levels of sun exposure and skin protection for children during summer is under way.

Development of an instrument for monitoring adolescent health issues.

The aim of the project was to develop a survey instrument to monitor relevant health status and health-related behaviors among secondary school students. The development of the instrument occurred in three main phases: collection of existing surveys, workshops with relevant health professionals and focus groups with adolescents. The topics for inclusion were refined using Health Goals and Targets for Australian Children and Youth and consultations with health professionals, and included alcohol/illicit drug use, smoking, nutrition, exercise, injury, mental health, violence and sexual health. Content validity was demonstrated through a comprehensive literature review, review and application of existing instrumentation, dialog and exchange with health professionals, and focus groups with adolescents. The process of peer review through correspondence with health professionals, and the coordination of workshops and focus groups established face validity. Responses from students also indicated that they interpreted the questions as intended. The instrument was piloted in five secondary schools during class periods. Process evaluation was also conducted to determine the appropriateness of the survey and the procedures used in administering the survey. Feedback from school staff was supportive and favorable with respect to the choice of issues. Reliability was assessed by a test-re-test procedure 2 weeks apart. In general, most of the questions showed moderate to high reliability (kappa > 0.5) indicating agreement of 50% or greater. This instrument was developed as a monitoring instrument and places emphasis on determining prevalence levels of a range of health issues and health behaviors to assist with identifying clustering patterns of negative health outcomes. Although the instrument is primarily for use with students in school hours, the nature of the instrument allows modification for use in older groups of adolescents and out-of-school youth. The final version of the questionnaires for senior and junior students can be accessed via the Internet (http://;+www.spmed.uq.edu.au/CHPCPR /qu estionnaire).

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.