Physical Workload On Neck And Shoulder Muscles During Military Helicopter Flight

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Abstrakt

PHYSICAL WORKLOAD ON NECK AND SHOULDER MUSCLES DURING MILITARY HELICOPTER FLIGHT

Murray M, 1, Lange B, 2, Olsen H.B, 1, Søgaard K, 1, Sjøgaard G, 1

1Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, DK
2Department of Anesthesia and Intensive Care Medicine, Odense University Hospital, DK
E-mail: mmurray@health.sdu.dk

AIM: Flight-related neck/shoulder pain is common among military helicopter pilots and crew members. During flight, the flight helmet and additional Night Vision Goggles (NVG) pose a considerable load on the cervical spine. The aim of this study was to quantify the physical workload on the cervical muscles during flight with and without NVG.

METHODS: Nine pilots and nine crew members participated in this study. Before a flight, one pilot and one crew member were equipped with 6 wireless electromyography sensors, positioned bilaterally above trapezius m. (TRA), the upper neck extensors (UNE) and sternocleido-mastoid m. (SCM). Nine repetitive flights were completed, encompassing: Patient-Transport (PT), Patient-Transport with NVG (PT+NVG) and Search And Rescue with NVG (SAR+NVG). A standard helmet (1.85 kg) and NVG (1.1 kg) were used. The EMG signal was normalized using Maximal Voluntary Contractions (MVC) and analyzed for changes in amplitude and distribution of muscle activity by an Amplitude Probability Distribution Function (APDF).

RESULTS: MVC for shoulder elevation (right/left) was: 136.8±41.3 / 120.6±47.0 Nm, and for cervical-flexion and extension: 32.2±14.0 and 42.5±10.2 Nm. EMG sampling time was: 16.9±5.1 min for PT, 22.7±10.8 min for PT+NVG and 21.3±11.1 min for SAR+NVG. Mean muscle activity (%MVE) in UNE was significantly higher than TRA and SCM during all flights, except for crew members during PT. UNE showed significantly higher %MVE during SAR+NVG compared to PT or PT+NVG for pilots. An APDF analysis showed that UNE during SAR+NVG was significantly higher than TRA and SCM, during 10% (APDF 0.1), 50% (APDF 0.5) and 90% (APDF 0.9) of total flight time.

CONCLUSION:
Muscle activity in the upper neck muscles was high with an overall level of 10% MVE or above for half of total flight-time. This high level of sustained muscle activity may indicate a risk for developing neck disorders among helicopter crew and pilots.
OriginalsprogEngelsk
Publikationsdato2014
Antal sider1
StatusUdgivet - 2014
BegivenhedISEK 2014: XX Congress of the International Society of Electrophysiology and Kinesiology - Rom, Italien
Varighed: 14. jul. 201418. jul. 2014
Konferencens nummer: XX

Konference

KonferenceISEK 2014
NummerXX
LandItalien
ByRom
Periode14/07/201418/07/2014

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