title: Impact test comparisons of 20th and 21st century American football helmets.
abstract: OBJECTIVE
  Concussion is the signature American football injury of the 21st century. Modern varsity helmets, as compared with vintage leather helmets, or "leatherheads," are widely believed to universally improve protection by reducing head impact doses and head injury risk for the 3 million young football players in the US. The object of this study was to compare the head impact doses and injury risks with 11 widely used 21st century varsity helmets and 2 early 20th century leatherheads and to hypothesize what the results might mean for children wearing similar varsity helmets.
  
  
  METHODS
  In an injury biomechanics laboratory, the authors conducted front, oblique front, lateral, oblique rear, and rear head impact tests at 5.0 m/second using helmeted headforms, inducing near- and subconcussive head impact doses on par with approximately the 95th percentile of on-field collision severity. They also calculated impact dose injury risk parameters common to laboratory and on-field traumatic neuromechanics: linear acceleration, angular acceleration, angular velocity, Gadd Severity Index, diffuse axonal injury, acute subdural hematoma, and brain contusion.
  
  
  RESULTS
  In many instances the head impact doses and head injury risks while wearing vintage leatherheads were comparable to or better than those while wearing several widely used 21st century varsity helmets.
  
  
  CONCLUSIONS
  The authors do not advocate reverting to leather headgear, but they do strongly recommend, especially for young players, instituting helmet safety designs and testing standards, which encourage the minimization of linear and angular impact doses and injury risks in near- and subconcussive head impacts.
authors: Cleveland Clinic Spine Research Laboratory, 1730 West 25th Street, Cleveland, Ohio 44113, USA. bartsca@ccf.org
authors: Adam
authors: A
authors: Bartsch
authors: Edward
authors: E
authors: Benzel
authors: Vincent
authors: V
authors: Miele
authors: Vikas
authors: V
authors: Prakash
mesh_terms: D000054:Acceleration; D001696:Biomechanical Phenomena; D005538:Football / Q000293:injuries*; D016489:Head Injuries, Closed / Q000517:prevention & control*; D006260:Head Protective Devices; D006801:Humans; D008954:Models, Biological