Irving S Scher1, Lenka L Stepan2, Jasper E Shealy2, Ryan W Hoover3. 1. Guidance Engineering and Applied Research, Seattle, WA, USA. Electronic address: scher@guidanceengineering.com. 2. Guidance Engineering and Applied Research, Seattle, WA, USA. 3. CAPE, Westfield, Indiana, USA.
Abstract
OBJECTIVES: The injury mitigation capabilities of foam, ski-area padding was examined for headfirst impacts. DESIGN AND METHODS: A custom-made pendulum impactor system was constructed using an instrumented, partial 50th-percentile-male Hybrid-III anthropomorphic testing device (ATD). For each test, the ATD was raised 1.0m, released, and swung into a 20-cm diameter wooden pole. Test trials were conducted with the wooden pole covered by ski area padding (five conditions of various foam types and thicknesses) or unpadded. Linear (linear acceleration and HIC15) and angular (angular velocity, angular acceleration, and BrIC) kinematics were examined and used to estimate the likelihood of severe brain injury. Cervical spine loads were compared to the injury assessment reference values for serious injury. Further tests were conducted to examine the changes produced by the addition of a snowsport helmet. RESULTS: 38 test trials were recorded with a mean (±sd) impact speed of 4.2 (±0.03) m/s. Head, resultant linear acceleration, HIC15, and associated injury likelihoods were tempered by ski area padding at the impact speed tested. Ski area padding did not reduce brain injury likelihood from rotational kinematics (p>0.05 for all comparisons) or reduce the cervical spine compression below injury assessment reference values. The addition of a helmet did not reduce significantly the likelihoods of brain or cervical spine injury. CONCLUSIONS: At the impact speed tested, ski area padding provided limited impact protection for the head (for linear kinematics) but did not protect against severe brain injuries due to rotational kinematics or serious cervical spine injuries.
OBJECTIVES: The injury mitigation capabilities of foam, ski-area padding was examined for headfirst impacts. DESIGN AND METHODS: A custom-made pendulum impactor system was constructed using an instrumented, partial 50th-percentile-male Hybrid-III anthropomorphic testing device (ATD). For each test, the ATD was raised 1.0m, released, and swung into a 20-cm diameter wooden pole. Test trials were conducted with the wooden pole covered by ski area padding (five conditions of various foam types and thicknesses) or unpadded. Linear (linear acceleration and HIC15) and angular (angular velocity, angular acceleration, and BrIC) kinematics were examined and used to estimate the likelihood of severe brain injury. Cervical spine loads were compared to the injury assessment reference values for serious injury. Further tests were conducted to examine the changes produced by the addition of a snowsport helmet. RESULTS: 38 test trials were recorded with a mean (±sd) impact speed of 4.2 (±0.03) m/s. Head, resultant linear acceleration, HIC15, and associated injury likelihoods were tempered by ski area padding at the impact speed tested. Ski area padding did not reduce brain injury likelihood from rotational kinematics (p>0.05 for all comparisons) or reduce the cervical spine compression below injury assessment reference values. The addition of a helmet did not reduce significantly the likelihoods of brain or cervical spine injury. CONCLUSIONS: At the impact speed tested, ski area padding provided limited impact protection for the head (for linear kinematics) but did not protect against severe brain injuries due to rotational kinematics or serious cervical spine injuries.