title: The effect of hardhats on head and neck response to vertical impacts from large construction objects.
abstract: We evaluated the effectiveness of hardhats in attenuating head acceleration and neck force in vertical impacts from large construction objects. Two weight-matched objects (lead shot bag and concrete block) weighing 9.1 kg were dropped from three heights (0.91 m, 1.83 m and 2.74 m) onto the head of a 50th percentile male Hybrid III anthropomorphic test device (ATD). Two headgear conditions were tested: no head protection and an ANSI Type-I, Class-E hardhat. A third headgear condition (snow sport helmet) was tested at 1.83 m for comparison with the hardhat. Hardhats significantly reduced the resultant linear acceleration for the concrete block impacts by 70-95% when compared to the unprotected head condition. Upper neck compression was also significantly reduced by 26-60% with the use of a hardhat when compared to the unprotected head condition for the 0.91 and 1.83 m drop heights for both lead shot and concrete block drop objects. In this study we found that hardhats can be effective in reducing both head accelerations and compressive neck forces for large construction objects in vertical impacts.
authors.affiliation: Guidance Engineering and Applied Research, 3909 California Ave, SW Suite 202, Seattle, WA 98116, USA. Electronic address: suderman@guidanceengineering.com.
authors.forename: Bethany L
authors.initials: BL
authors.lastname: Suderman
authors.affiliation: CAPE, 18881 US 31 North, Westfield, IN 46074, USA. Electronic address: rhoover@imminet.com.
authors.forename: Ryan W
authors.initials: RW
authors.lastname: Hoover
authors.affiliation: Applied Biomechanics Laboratory, Department of Mechanical Engineering, University of Washington, 501 Eastlake Ave E, Suite 102, Seattle, WA 98109, USA. Electronic address: rc@u.washington.edu.
authors.forename: Randal P
authors.initials: RP
authors.lastname: Ching
authors.affiliation: Guidance Engineering and Applied Research, 3909 California Ave, SW Suite 202, Seattle, WA 98116, USA; Applied Biomechanics Laboratory, Department of Mechanical Engineering, University of Washington, 501 Eastlake Ave E, Suite 102, Seattle, WA 98109, USA.
authors.forename: Irving S
authors.initials: IS
authors.lastname: Scher
mesh_terms: D000054:Acceleration; D001696:Biomechanical Phenomena; D006259:Craniocerebral Trauma / Q000517:prevention & control*; D006257:Head / Q000502:physiology*; D006260:Head Protective Devices; D006801:Humans; D008348:Manikins; D009333:Neck / Q000502:physiology*; D019838:Neck Injuries / Q000517:prevention & control*
keywords: Dropped object; Hardhat; Head acceleration; Neck compression; Vertical impact