Crew-Friendly Countermeasures Against Musculoskeletal Injuries in Aviation and Spaceflight

Abstract

Aviation and space medicine face many common musculoskeletal challenges that manifest in crew of rotary-wing aircraft (RWA), high-performance jet aircraft (HPJA), and spacecraft. Furthermore, many astronauts are former pilots of RWA or HPJA. Flight crew are exposed to recurrent musculoskeletal risk relating to the extreme environments in which they operate, including high-gravitational force equivalents (g-forces), altered gravitational vectors, vibratory loading, and interaction with equipment. Several countermeasures have been implemented or are currently under development to reduce the magnitude and frequency of these injuries. Cervical and lumbar spine, as well as extremity injuries, are common to aviators and astronauts, and occur in training and operational environments. Stress on the spinal column secondary to gravitational loading and unloading, ± vibration are implicated in the development of pain syndromes and intervertebral disk pathology. While necessary for operation in extreme environments, crew-support equipment can contribute to musculoskeletal strain or trauma. Crew-focused injury prevention measures such as stretching, exercise, and conditioning programs have demonstrated the potential to prevent pre-flight, in-flight, and post-flight injuries. Equipment countermeasures, especially those addressing helmet mass and center of gravity and spacesuit ergonomics, are also key in injury prevention. Furthermore, behavioral and training interventions are required to ensure that crew are prepared to safely operate when faced with these exposures. The common operational exposures and risk factors between RWA and HPJA pilots and astronauts lend themselves to collaborative studies to develop and improve countermeasures. Countermeasures require time and resources, and careful consideration is warranted to ensure that crew have access to equipment and expertise necessary to implement them. Further investigation is required to demonstrate long-term success of these interventions and inform flight surgeon decision-making about individualized treatment. Lessons learned from each population must be applied to the others to mitigate adverse effects on crew health and well-being and mission readiness.

Risks and Countermeasures for the Musculoskeletal systems in the Extreme Environment of Aviators and Astronauts

“…The only times astronauts will be exposed to this would mainly be during takeoff and landing or other instances when thrusters are ignited. Intense vibrations can affect crew through fatigue, microtrauma, nerve impingement, ligamentous injury, and degenerative changes [20,21]. Though no significant injuries have been specifically linked to this it could be more of a threat after BMD and muscle mass loss on long term missions that have their own return launches and landings.…”

“…There was a decrease in apparent neck pain and increased functionality of neck and shoulder muscles [34]. NECK X ® , depicted in figure 5, is a patented portable cervical exercise device (PCED) device based on our previous research to strengthen neck muscles for military pilots [21]. Usage of this device in the prescribed physical therapy has been effective in reducing strain for pilots [21].…”

“…NECK X ® , depicted in figure 5, is a patented portable cervical exercise device (PCED) device based on our previous research to strengthen neck muscles for military pilots [21]. Usage of this device in the prescribed physical therapy has been effective in reducing strain for pilots [21]. Literature review shows clearly that exercising the neck and shoulders can help mitigate neck pain that can ultimately make pilots unable to fly any more.…”

“…Neck and low back pain in aviation and spaceflight occurs in 56-89% of flight crew [4,21]. The spine and its structures function via a concept known as tensegrity, perhaps better known as "core" [59][60][61].…”

“…When deep neck flexors and extensors get stronger, neck pain reports go down [21,66,67]. When the neck is unloaded while activating deep spine stabilizers, aircrew reported minimal to no residual pain, and there was greater muscle activation.…”