Technical Brief

Inertial Properties of Football Helmets

[+] Author and Article Information
James R. Funk

Biocore LLC,
1621 Quail Run,
Charlottesville, VA 22911
e-mail: jfunk@biocorellc.com

Roberto E. Quesada

Biocore LLC,
1621 Quail Run,
Charlottesville, VA 22911
e-mail: rquesada@biocorellc.com

Alexander M. Miles

Biocore LLC,
1621 Quail Run,
Charlottesville, VA 22911
e-mail: amiles@biocorellc.com7

Jeff R. Crandall

Biocore LLC,
1621 Quail Run,
Charlottesville, VA 22911
e-mail: jcrandall@biocorellc.com

Manuscript received February 6, 2017; final manuscript received February 27, 2018; published online April 30, 2018. Assoc. Editor: Barclay Morrison.

J Biomech Eng 140(6), 064501 (Apr 30, 2018) (7 pages) Paper No: BIO-17-1046; doi: 10.1115/1.4039673 History: Received February 06, 2017; Revised February 27, 2018

The inertial properties of a helmet play an important role in both athletic performance and head protection. In this study, we measured the inertial properties of 37 football helmets, a National Operating Committee on Standards for Athletic Equipment (NOCSAE) size 7¼ headform, and a 50th percentile male Hybrid III dummy head. The helmet measurements were taken with the helmets placed on the Hybrid III dummy head. The center of gravity and moment of inertia were measured about six axes (x, y, z, xy, yz, and xz), allowing for a complete description of the inertial properties of the head and helmets. Total helmet mass averaged 1834±231 g, split between the shell (1377±200 g) and the facemask (457±101 g). On average, the football helmets weighed 41±5% as much as the Hybrid III dummy head. The center of gravity of the helmeted head was 1.1±3.0 mm anterior and 10.3±1.9 mm superior to the center of gravity of the bare head. The moment of inertia of the helmeted head was approximately 2.2±0.2 times greater than the bare head about all axes.

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Grahic Jump Location
Fig. 1

Photograph of a center of gravity measurement of a helmeted head in configuration 5

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Fig. 2

Summary of measurement configurations

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Fig. 3

Helmets sorted in order of increasing helmet shell mass

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Fig. 4

Center of gravity measurements (generic helmet outline shown)

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Fig. 5

Shell and facemask components of helmet center of gravity (generic helmet outline shown)

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Fig. 6

Helmets sorted in order of increasing sagittal plane (Iy) moment of inertia

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Fig. 7

Helmet moment of inertia versus mass



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