Neck muscle activation and head postures in common high performance aerial combat maneuvers

Introduction: Neck injuries are common in high performance combat pilots and have been attributed to high gravitational forces and the non-neutral head postures adopted during aerial combat maneuvers. There is still little known about the pathomechanics of these injuries.

Methods: Six Royal Australian Air Force Hawk pilots flew a sortie that included combinations of three +Gz levels (1, 3, and 5) and four head postures (Neutral, Turn, Extension, and Check-6). Surface electromyography from neck and shoulder muscles was recorded in flight. Three-dimensional measures of head postures adopted in flight were estimated postflight with respect to end-range of the cervical spine using an electromagnetic tracking device.

Results: Mean muscle activation increased significantly with both increasing +Gz and non-neutral head postures. Check-6 at +5 Gz (mean activation of all muscles = 51% MVIC) elicited significantly greater muscle activation in most muscles when compared with Neutral, Extension, and Turn head postures. High levels of muscle co-contraction were evident in high acceleration and non-neutral head postures. Head kinematics showed Check-6 was closest to end-range in any movement plane (86% ROM in rotation) and produced the greatest magnitude of rotation in other planes. Turn and Extension showed a large magnitude of rotation with reference to end-range in the primary plane of motion but displayed smaller rotations in other planes.

Discussion: High levels of neck muscle activation and co-contraction due to high +Gz and head postures close to end range were evident in this study, suggesting the major influence of these factors on the pathomechanics of neck injuries in high performance combat pilots.

Hypertrophy in the cervical muscles and thoracic discs in bed rest?

The impact of prolonged bed rest on the cervical and upper thoracic spine is unknown. In the 2nd Berlin BedRest Study (BBR2-2), 24 male subjects underwent 60-day bed rest and performed either no exercise, resistive exercise, or resistive exercise with whole body vibration. Subjects were followed for 2 yr after bed rest. On axial cervical magnetic resonance images from the skull to T3, the volumes of the semispinalis capitis, splenius capitis, spinalis cervicis, longus capitis, longus colli, levator scapulae, sternocleidomastoid, middle and posterior scalenes, and anterior scalenes were measured. Disc height, anteroposterior width, and volume were measured from C2/3 to T6/7 on sagittal images. The volume of all muscles, with the exception of semispinalis capitis, increased during bed rest (P < 0.025). There were no significant differences between the groups for changes in the muscles. Increased upper and midthoracic spine disc height and volume (P < 0.001) was seen during bed rest, and disc height increases persisted at least 6 mo after bed rest. Increases in thoracic disc height were greater (P = 0.003) in the resistive vibration exercise group than in control. On radiological review, two subjects showed new injuries to the mid-lower thoracic spine. One of these subjects reported a midthoracic pain incident during maximal strength testing before bed rest and the other after countermeasure exercise on day 3 of bed rest. We conclude that bed rest is associated with increased disc size in the thoracic region and increases in muscle volume at the neck. The exercise device needs to be modified to ensure that load is distributed in a more physiological fashion.

Factors associated with breast and cervical cancer screening behaviours

To investigate the factors associated with the use of screening mammography for breast cancer and cervical smear tests for cervical cancer, a theoretical framework was used comprising elements from the Health Belief Model, the Theory of Reasoned Action, and illness representations from the self-regulatory model. Items reflecting older women’s illness representations about cancer and cancer screening were derived from an earlier qualitative study. Using a highly structured interview schedule, telephone interviews were conducted with 1,200 women aged 50-70 years. There were considerable similarities between the factors associated with both mammography and cervical smear test behaviours. The factors associated with screening mammography behaviour were: perceived barriers, perceived benefits, social influence, the illness representations, and marital status. The factors associated with cervical smear test behaviour were: perceived barriers, perceived benefits, emotions as a cause of cancer, feeling frightened of cancer, the illness representations, having a usual general practitioner, and being younger.

Near normalisation of lumbar spine bone density in young women with osteopenia recovered from adolescent onset anorexia nervosa: a longitudinal study

To investigate the effect of the progression of adolescent onset anorexia nervosa (AN) on bone parameters we followed two cohorts (Disease cohort and recovered cohort) of adolescents for a total of 5.2 years. In the 'Disease' cohort (n = 18), lumbar spine bone density (BMD) was reduced by 0.6 SD after 0.8 years of disease and was reduced a further 1.0 SD after a total 2.5 years of disease (p < 0.001). At the third lumbar vertebra there was bone loss (-3.7%, p < 0.05) resulting in reduced volumetric BMD (-5.1%, p < 0.08). In the 'recovered' cohort, lumbar spine BMD was reduced by 1.9 SD after 1.7 years of disease, and increased by 1.5 SD after 2.7 years of recovery (p < 0.001). At the third lumbar vertebra there was an increase in bone mass (20.5%, p < 0.001) and bone volume (14.1%, p < 0.001), resulting in increased volumetric BMD (6.3%, p < 0.08). Normalisation of lumbar spine BMD may be achieved in patients with adolescent onset AN when the successful recovery of body weight is combined with the return of regular menses.

Comparing external and internal dorsal-spine bands to interpret the age and growth of the giant lantern shark, Etmopterus baxteri (Squaliformes: Etmopteridae)

The giant lantern shark, Etmopterus baxteri, is taken as bycatch of commercial fisheries that operate in deepwater off southeastern Australia. Bands on the second dorsal spine were used to obtain age estimates. The number of bands on the external surface of the spine and within the inner dentine layer increased with animal length. Most spines had more bands on the external surface, and the rate of band formation was significantly different between the external surface and the inner dentine layer. Females had a maximum of 57 external bands and 26 internal bands, while males had up to 48 external bands and 22 internal bands. Age estimates from external bands suggest maturity (A ₅₀) at 20 years for males and 30 years for females. Internal band age estimates suggest maturity at 10.5 years for males and 11.5 years for females. Although there is a large discrepancy between these two preliminary (i.e., unvalidated) age estimates, they both suggest that E. baxteri is a long-lived and late maturing species that is likely to be susceptible to over fishing.

Papuan Spine-tailed Swifts Mearnsia novaeguineae on Boigu Island, Torres Strait, Queensland

Three Papuan Spine-tailed Swifts Mearnsia novaeguineae were seen together on 17 November 2004 on Boigu Island, Torres Strait, Queensland. They were watched for a period of 7 minutes as they circled low over a small freshwater wetland, and ~70 digital photographs of the birds were obtained. This record was unanimously accepted by the Birds Australia Rarities Committee as the first of this species for Australian territory.

Cervical cancer services for Indigenous Women: Advocacy, Community-Based Research and Policy Change in Australia

Collaborative research undertaken in the state of Queensland, Australia, resulted in major changes in cervical cancer screening and treatment for Indigenous women. Guided by an Indigenous statewide reference group and with an Indigenous researcher playing a lead role, qualitative data were collected using interviews, focus groups, and larger community meetings; and case studies were conducted with health workers and community members from diverse rural, remote and urban communities, to explore the different cultural and structural factors affecting understanding and awareness of cervical cancer and Indigenous women's use of and access to health services for screening, diagnosis and treatment. These data were supplemented by an analysis of clinical data and health service checklists. We discuss the methodology and summarize the key social and structural factors that discourage women from presenting for screening or returning for follow-up. These include women's misunderstanding of cervical cancer screening, fear of cancer, distrust of health services, poor recall and follow-up systems, and the economic and social burden to women presenting for treatment. We describe how the research process and subsequent activities provided Indigenous women with a vehicle for their own advocacy, resulting in important policy and program changes.

Influence of posture on the range of axial rotation and coupled lateral flexion of the thoracic spine

Objective
This study examines the influence of posture on the range of axial rotation of the thorax and the range and direction of the coupled lateral flexion.

Methods
The ranges of mid thoracic axial rotation and coupled lateral flexion were measured in 52 asymptomatic subjects (aged 18-43 years) using an optical motion analysis system. To examine the influence of posture on primary and coupled motion, we initiated axial rotation from a neutral sitting posture and from end-range thoracic flexion and extension.

Results
There was a significant decrease in the range of thoracic rotation in flexion compared with the neutral and extended postures (P < .001). The mean range of coupled lateral flexion was 8.9% of the axial rotation range in the neutral posture and increased to 14.3% and 23.2% in the extended and flexed postures, respectively. Patterns of coupled motion varied between subjects, but an ipsilateral pattern was more common in the flexed posture, whereas a contralateral pattern was more common in the neutral and extended postures.

Conclusions
The ranges and patterns of coupled motion of the thorax appear to be strongly influenced by the posture from which the movement is initiated. This has important implications in relation to the interpretation of clinical tests of thoracic motion and in consideration of mechanisms of development of thoracic pain disorders.

Options for change in the Australian cervical cancer screening program in context of HPV detection and vaccination

Introduction:
Cervical cancer screening has been implemented for over a decade in Australia and has significantly reduced the mortality and morbidity of the disease. The emergence of new technologies for cervical cancer, such as the Human Papillomavirus (HPV) vaccine and DNA testing has encouraged debate regarding the effective use of resources in cervical cancer prevention. The present study evaluates the cost-effectiveness, from a health sector perspective, of various screening strategies in the era of these new technologies.

Methods:
A stochastic epidemiological model using a discrete event and continuous algorithm was developed to describe the natural history of cervical cancer. By allowing one member of the cohort into the model at a time, this micro-simulation model encompasses the characteristics of heterogeneity and can track individual life histories. To evaluate the cost-effectiveness of the HPV vaccine a Markov model was built to simulate the effect on the incidence of HPV and subsequent cervical cancer. A number of proposed screening strategies were evaluated with the stochastic model for the application of HPV DNA testing, with changes in the screening interval and target population. Health outcomes were measured by Disability-Adjusted Life-Years (DALYs), adjusted for application within an evaluation setting (i.e. the mortality component of the DALY was adjusted by a disability weight when early mortality due to cervical cancer is avoided). Costs in complying with the Australian updated guidelines were assessed by pathway analysis to estimate the resources associated with cervical cancer and its pre-cancerous lesion treatment. Sensitivity analyses were performed to investigate the key parameters that influenced the cost-effectiveness results.

Results:
Current practice has already brought huge health gain by preventing more than 4,000 deaths and saving more than 86,000 life-years in a cohort of a million women. Any of the alternative screening strategies alter the total amount of health gain by a small margin compared to current practice. The results of incremental analyses of the alternative screening strategies compared to current practice suggest the adoption of the HPV DNA test as a primary screening tool every 3 years commencing at age 18, or the combined pap smear/HPV test every 3 years commencing at age 25, are more costly than current practice but with reasonable ICERs (AUD$1,810 per DALY and AUD$18,600 per DALY respectively). Delaying commencement of Pap test screening to age 25 is less costly than current practice, but involves considerable health loss. The sensitivity analysis shows, however, that the screening test accuracy has a significant impact on these conclusions. Threshold analysis indicates that a sensitivity ranging from 0.80 to 0.86 for the combined test in women younger than 30 is required to produce an acceptable incremental cost-effectiveness ratio.

Conclusions:
The adoption of HPV and combined test with an extended screening interval is more costly but affordable, resulting in reasonable ICERs. They appear good value for money for the Australian health care system, but need more information on test accuracy to make an informed decision. Potential screening policy change under current Australian HPV Vaccination Program is current work in progress. A Markov model is built to simulate the effect on the incidence of HPV and subsequent cervical cancer. Adoption of HPV DNA test as a primary screening tool in the context of HPV vaccination is under evaluation.

Participation, relational justice and social identity in cervical cancer screening

Extending existing health literature by drawing on social and community psychology, this thesis represents the first attempt to explore the conceptualisation of 'participation' in cervical cancer screening. Quantitative and qualitative findings suggested that women's experiences of 'patient participation' and 'voice opportunity' were important and related to various social processes and variables in this health context. Using four case studies, the professional portfolio demonstrates a biopsychosocial approach to assessment and intervention as used by a provisional health psychologist working with clients with intellectual disabilities in order to promote sexual health.