Abstract
In 1903, the Wright Brothers made the first controlled and sustained flight of an engine powered aircraft. Within seven years of this first flight, it was forecast that gaining ‘command of the air’ would be of great importance in future battle. These forecasts gained increased significance during World War I, and have continued to see increased attention as air power theory has evolved. Recent work has demonstrated that achieving ‘air superiority’ is indeed crucial to victory, and was observed to be a stronger predictor of battlefield outcome than other factors including modern ground forces system, and general measures of military power. Fighter aircraft (also known as fast jets) are powerful and highly manoeuvrable, and have become a critical component to gaining and maintaining such air superiority, offering air-to-air, air-to-surface, and electronic attack capabilities.Fighter aircrew (also known as fast jet aircrew) thus work in a dynamic and demanding environment where they are exposed to high and repetitive forces. The combination of high +Gz forces, heavy helmets and helmet-mounted equipment, and the requirement to maintain vision in all quarters, has resulted in fighter aircrew having to endure high forces upon their necks, and often so with their necks and trunks in awkward positions. Unsurprisingly, fighter aircrew have been observed to have a high prevalence of neck pain, which can be detrimental to operational capability by reducing their performance in the air and by being grounded. Additionally, neck pain can come at a great financial cost, particularly through course dropout and early career termination.
Therefore, effective preventative interventions for fighter aircrew are needed. Frameworks have been developed in other fields (such as sports injury epidemiology), to guide and assist injury prevention efforts. Common within these frameworks is the need to first establish the extent of the problem via accurate surveillance, and establish the aetiology and mechanisms of such injuries. Once these are established, preventative interventions can be better targeted.
The systematic review and meta-analysis we conducted (chapter 2) identified a number of contributory risk factors for neck pain among fighter aircrew. However, the predominance of cross-sectional designs made it difficult to draw conclusions as to cause and effect. Furthermore, there was heterogeneity among studies of what constituted a ‘recordable injury’ (i.e. what was defined as neck pain having occurred), and there was a reliance upon surveillance methods that required participants recall over long periods of time. Such findings indicated a need for reaching consensus on recordable injury definitions, developing accurate surveillance methods, and conducting prospective studies.
Building upon this work, consensus was sought using a Delphi study (chapter 3) with international experts on recordable injury definitions and important content for use in a surveillance tool for fighter aircrew. A surveillance tool was developed, the University of Canberra Fast Jet Aircrew Musculoskeletal Questionnaire (UC-FJAMQ), and refined following input from Royal Australian Air Force (RAAF) fighter aircrew. Following the tool’s use with RAAF fighter aircrew, evaluation of its validity using multilevel factor analysis (MFA) revealed three distinct dimensions among the 11 items used to determine overall severity: operational capability, symptoms, and care-seeking. Symptom severity and seeking medical attention were found to be poor indicators of the impact injuries had upon operational capability, with correlations ranging from -0.067 to 0.319. Comparison of the UC-FJAMQ to routine methods of injury surveillance (injury registers completed by physiotherapists embedded with RAAF fighter aircrew) saw the UC-FJAMQ identify 79% of all time-loss episodes, compared to the routine methods identifying only 49%. Such results demonstrated the utility of the UC-FJAMQ for injury surveillance among fighter aircrew, and reiterated the importance of not relying on routine methods of surveillance alone.
Further exploring the data captured by the UC-FJAMQ and routine methods of surveillance in the above validation study, the pattern of musculoskeletal complaints experienced by RAAF FJA over the two-year period were described. In comparison to other body regions, the neck region had the highest prevalence and incidence of musculoskeletal complaints, and the highest burden related to overall cumulative severity and the cumulative operational impact sub-score. A similar pattern was observed for time-loss episodes with the neck region having the highest prevalence, incidence, and burden. The findings also highlighted the need for all spinal regions (not just the neck) to be considered in future prevention efforts.
Using the methodological recommendations from the systematic review reported in chapter two, and utilising the UC-FJAMQ developed and validated in the study reported in chapter three, a prospective study was conducted with RAAF fighter aircrew over a two-year period (four 5-month reporting periods) examining potential contributory risk factors for neck pain. Using mixed-effects logistic regression, adjusting for potential confounders, and examining of non-linear relationships, 44 baseline factors and 26 weekly measures were examined. Previous neck pain, higher worry scores, larger acute flying workloads, more weekly flights, and larger acute and chronic strength and conditioning (S&C) workloads, were factors identified to increase the risk of a neck-related musculoskeletal complaint episode (NRMCE). Interestingly, significant non-linear relationships were identified between risk of NRMCE and the following factors: chronic flying workloads, acute and chronic sleep quality scores, and absolute isometric strength of neck rotation and trunk flexion. However, the following factors were found not to have a significant relationship with risk of NRMCE: demographics, flying history, anthropometry measures, neck and trunk range of motion, and participation in two fighter aircrew specific S&C programs. Findings from this study provide important direction for future prevention programs including those using S&C programs to reduce risk and those using monitoring and screening to identify those with increased risks.
The work contained in this thesis has firstly demonstrated that the complexities of conducting research with fighter aircrew can indeed be overcome. Secondly, it has provided tools and further knowledge for future work to develop, implement, and evaluate targeted and effective programs for preventing neck pain among fighter aircrew.
| Date of Award | 2025 |
|---|---|
| Original language | English |
| Supervisor | Phillip NEWMAN (Supervisor) & Wayne SPRATFORD (Supervisor) |