Without question, flying is the best career in the world! As we know, it is with its inherent risks, but we can ultimately mitigate those through training, standards, procedures and our individual roles and responsibilities as a crew.
How is your back?
Is it from your poor, manual, handling practice? We are, after all, in the ‘real world’ and not a classroom, so sometimes we must get in a less than favorable position to deliver patient care. In this episode of ‘Skids Up’, I will astound you with my plethora of random medical knowledge!
Could your back problems be caused by a not well known and quite common problem for helicopter crews…?
The high incidence of back pain in helicopter pilots has been attributed to vibration and the in-flight pilot’s posture. Helicopter vibration has a peak power at frequencies around 5 Hz, which is within the range that the human upper body presents resonance frequency
Bad seating posture is a common fault amongst pilots, but what about the rest of us? We are not necessarily as rigid in our seat and have a degree of flexibility to move (although limited by our safety harness). There are very few studies focusing on the non-pilot aircrew.
Myself and many I know are of a generation that is ‘now getting old’. We have routinely knelt in the helicopter doorway, stood on the skids, and performed a plethora of flight tasks associated with the rear crew’s role. We are all now experiencing severe lumbar pain, but also our knees and wrists are beginning to suffer.
In the construction industry, there is extensive research and guidance on Hand-Arm Vibration Syndrome (HAVS) as a result of workers using cutting tools, drills, grinders, etc. HAVS involves damage to three different systems in the fingers, hands and arms:
1. Vascular system: The best known disease component of HAVS is Vibration White Finger (VWF), which is primarily due to damage to the blood vessels in the fingers and hands, and results in a decrease in the blood supply to the fingers.
2. Nervous system: The nerves in the fingers can be damaged and/or compressed, which results in digital neuropathies and/or compression neuropathies (such as carpal tunnel syndrome).
3. Musculoskeletal system: The bones, joints and muscles can be damaged, resulting in arthritis, contractures (inability to straighten the fingers) and tendinopathies (painful inflammation of the tendons).
In both the construction and offshore industry, measures such as approved anti-vibration gloves and other preventative measures have been implemented. However, for us as aircrew, this is not practical.
Airbus helicopters designed flight seats that reduce the vibration to tolerable levels, but then they do not become crash resistant in high G-forces, so they cannot be used.
So, where does that leave us?
Adjust your seat posture. If you’re kneeling in a doorway (e.g. SAR hoist), use kneepads and flexible straps as hand holds. You not only will look cool, but you will prevent the daily pain routine all of us ‘old aircrew’ have.
- Bongers PM, Hulshof CTJ, Dijkstra L, et al. Back pain and exposure to whole body vibration in helicopter pilots. Ergonomics 1990; 33:1007–26.
- de Oliveira CG, Nadal J. Back muscle electromyography of helicopter pilots in flight: effects of fatigue, vibration and posture. Aviat Space Environ Med 2004; 75:317–22.
- de Oliveira CG, Simpson DM, Nadal J. Lumbar muscle activity of helicopter pilots and whole-body vibration. J Biomech 2001; 43:1309 –15.
- El-Khatib A, Guillon F. Vertical vibration transmission through the lumbar spine of the seated subject – first results. J Sound Vib 1998; 215:763–73.
- Fritz M. Description of the relation between the forces acting in the lumbar spine and whole-body vibrations by means of transfer function. Clin Biomech 2000; 15:234 – 40.
- Froom P, Van Dyk D, Caine Y, et al. Lytic spondylolisthesis in helicopter pilots. Aviat Space Environ Med 1984; 55:556 –7.
- Griffin MJ. Whole-body biodynamics. In: Hand book of human vibration. San Diego: Academic Press; 1996:333– 47.
- Hansen B, Wagstaff AS. Low back pain in Norwegian helicopter aircrew. Aviat Space Environ Med 2001; 72:161– 4.
- ISO 2631–1: 1997 (E), Mechanical vibration and shock – Part 1: Evaluation of human exposure to whole-body vibration. Gene´ve: International Organization for Standardization; 1997.