Affiliations: Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, Waterloo, ON, Canada
Correspondence:
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Corresponding author: Jack P. Callaghan, Department of Kinesiology, Faculty of Applied Health Sciences, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada. Fax: +1 519 746 6776; E-mail:jack.callaghan@uwaterloo.ca
Abstract: BACKGROUND: Static postures and heavy helmets elicit neck pain in
many aircraft personnel during or after flight. Helmet-mounted equipment can
further increase neck loading and injury risk. OBJECTIVE: To quantify neck muscle activity changes as a function
of helmet configuration and static neck postures. METHODS: Eight male participants participated. Neck surface EMG was
measured bilaterally in each combination of 7 neck postures (neutral,
flexed, extended, twisted, laterally flexed, and two combination postures)
and 5 helmet-mounted equipment configurations (combinations of a helicopter
helmet, night-vision goggles (NVG), and a 600 g counterweight (CW)). RESULTS: Helmet configuration alone did not influence activity for
any muscle. Peak muscle activity was less than 5% of maximum voluntary
exertion for most trials. The highest neck extensor activity occurred when
wearing the helmet with CW and NVG engaged, while the lowest activity
occurred in the same setup but NVG in a disengaged position, and helmet
configuration effects varied by target posture. Muscle activity tended to be
greatest in extension and combination movements for the lateral muscles and
in flexion and flexion with rotation for the neck extensors. CONCLUSION: Neck posture influenced neck muscular demands more than
the configuration of helmet-mounted equipment. As such, cockpit layout may
play a primary role in mitigating neck injury risk factors.
