title: Biomechanics of the head for Olympic boxer punches to the face.
abstract: OBJECTIVE
  The biomechanics of the head for punches to the jaw and the risk of head injury from translational and rotational acceleration were studied. [figure: see text]
  
  
  METHODS
  Seven Olympic boxers from five weight classes delivered 18 straight punches to the frangible face of the Hybrid III dummy. Translational and rotational head acceleration, neck responses, and jaw pressure distribution were measured. High speed video recorded each blow and was used to determine punch velocity. Equilibrium was used to determine punch force, energy transfer, and power.
  
  
  RESULTS
  Punch force averaged 3427 (standard deviation (SD) 811) N, hand velocity 9.14 (SD 2.06) m/s, and effective punch mass 2.9 (SD 2.0) kg. Punch force was higher for the heavier weight classes, due primarily to a higher effective mass of the punch. Jaw load was 876 (SD 288) N. The peak translational acceleration was 58 (SD 13) g, rotational acceleration was 6343 (SD 1789) rad/s(2), and neck shear was 994 (SD 318) N.
  
  
  CONCLUSIONS
  Olympic boxers deliver straight punches with high impact velocity and energy transfer. The severity of the punch increases with weight class.
authors.affiliation: Sports Biomechanics Laboratory, Department of BioMedical Engineering, Wayne State University, 818 W. Hancock, Detroit, MI 48201, USA.
authors.forename: T J
authors.initials: TJ
authors.lastname: Walilko
authors.forename: D C
authors.initials: DC
authors.lastname: Viano
authors.forename: C A
authors.initials: CA
authors.lastname: Bir
mesh_terms: D000054:Acceleration; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D001835:Body Weight; D001914:Boxing / Q000293:injuries*; D006259:Craniocerebral Trauma / Q000209:etiology*; D005151:Facial Injuries / Q000150:complications*; D006260:Head Protective Devices; D006801:Humans; D007568:Jaw / Q000293:injuries; D007700:Kinetics; D012307:Risk Factors; D012399:Rotation