Determination of helmet CG and evaluation of neck injury potentials using

Gaur, S. J.; Joshi, V. V.; Aravindakshan, B.; Aravind, A. S.

Affiliations

¹Scientist ‘D’, Dept of Applied physics & Biodynamics, IAM, IAF, Bangalore - 560 017

²Senior Adv & SMO 40 Wg AF

³SSA, Dept of Applied Physics of Biodynamics, IAM,AIF, Bangalore - 560 017

⁴Sc ‘E’ HoD Applied Physics & Biomedical Engineering, IAM, IAF, Bangalore - 560 017

Abstract and keywords

A military flying helmet, besides providing head protection serves as a mounting platform for display visors, Night Vision Goggles (NVGs), Oxygen masks and radio telephony that improve pilot performance during a mis- sion. However, these systems may increase the potential for neck injury due to excess of head supported mass and/ or altered combined head and helmet system Centre-of- Gravity (CG) while increasing moment at the head neck joint. In present study, a 50th %tile Anthropometric Test Dummy (ATD) head was developed to asses mass properties of mid size helmets of Mirage, Su-30, Mig21 (LWI) and Gallet assembly on a Trifilar Pendulum. The mass of the ATD head was 3.33 kg and CG from head anatomical origin was (0.28, -0.01, and 1.41cms). The mass of the helmets under study varied from 1.61 to 2.54 kg. The X and Z CG coordinates were between -0.04 to 0.85 cms and 2.45 to 3.22 cms respectively. The neck torque at C7/T1 juncture due to helmet weight and X coordinate CG shift varied from 29.24 to 78.40 N-cms. The mass moment at head neck joint was between 19.18 to 38.43 Kg-cm. None of the helmets breached the CG shift limit of the Knox-Box criteria. However, a neck torque value above 78 N- cm for Gallet assembly could adversely affect the wearer’s ability to identify and track targets and in addition could increase the neck fatigue under long duration whole body vibration (WBV).

Keywords: Flight helmet; Headform; Centre of Gravity; Knox-Box; Neck Torque

Links

URL: http://medind.nic.in/iab/t13/i1/iabt13i1p37.pdf

Cited Works (4)

Year	Entry
2008	Gallagher HL, Caldwell E, Albery CB. Neck Muscle Fatigue Resulting from Prolonged Wear of Weighted Helmets. Wright-Patterson AFB, OH: Biomechanics Branch, Biosciences and Protection Division, Human Effectiveness Directorate, Air Force Research Laboratory; June 2008. Report No. AFRL-RH-WP-TR-2008-0096.
2004	Ivancevic V, Beagley N. Determining the Acceptable Limits of Head Mounted Loads. Edinburgh, South Australia, Australia: DSTO Systems Sciences Laboratory; April 2004. Defense Science and Technology Organization Report DSTO-TR-1577.
2005	Manoogian SJ, Kennedy EA, Duma SM. An Updated Literature Review of Musculoskeletal Injuries to the Human Neck and the Effects of Head-Supported Mass Worn by Soldiers. Fort Rucker, AL: U.S. Army Aeromedical Research Laboratory; October 2005. USAARL Contract Report CR-2006-01.
2005	Merkle AC, Kleinberger M, Uy OM. The effects of head-supported mass on the risk of neck injury in army personnel. Johns Hopkins APL Tech Dig. January–March 2005;26(1):75-83.

Cited By (3)

Year	Entry
2020	Ge X, Zhou Q, Liu Z. Ergonomic evaluation of pilot helmet and neck injury. In: Ahram T, ed. Advances in Human Factors in Wearable Technologies and Game Design. Proceedings of the AHFE 2019 International Conference on Human Factors and Wearable Technologies, and the AHFE International Conference on Game Design and Virtual Environments; July 24-28, 2019; Washington, DC. Cham, Switzerland: Springer Nature Switerzland AG; 2020:154-166. Advances in Intelligent Systems and Computing; vol 973.
2019	Derouin AJ, Fischer SL. Validation of a three-dimensional visual target acquisition system for evaluating the performance effects of head supported mass. Appl Ergon. April 2019;76:48-56.
2018	LeClair B, O'Connor PJ, Podrucky S, Lievers WB. Measuring the mass and center of gravity of helmet systems for underground workers. Int J Ind Ergon. March 2018;64:23-30.