OBJECTIVE: This study addresses impact biomechanics from boxing punches causing translational and rotational head acceleration. Olympic boxers threw four different punches at an instrumented Hybrid III dummy and responses were compared with laboratory-reconstructed NFL concussions.
METHODS: Eleven Olympic boxers weighing 51 to 130 kg (112–285 lb) delivered 78 blows to the head of the Hybrid III dummy, including hooks, uppercuts and straight punches to the forehead and jaw. Instrumentation included translational and rotational head acceleration and neck loads in the dummy. Biaxial acceleration was measured in the boxer’s hand to determine punch force. High-speed video recorded each blow. Hybrid III head responses and finite element (FE) brain modeling were compared to similarly determined responses from reconstructed NFL concussions.
RESULTS: The hook produced the highest change in hand velocity (11.0 ± 3.4 m/s) and greatest punch force (4405 ± 2318 N) with average neck load of 855 ± 537 N. It caused head translational and rotational accelerations of 71.2 ± 32.2 g and 9306 ± 4485 r/s2. These levels are consistent with those causing concussion in NFL impacts. However, the head injury criterion (HIC) for boxing punches was lower than for NFL concussions because of shorter duration acceleration. Boxers deliver punches with proportionately more rotational than translational acceleration than in football concussion. Boxing punches have a 65 mm effective radius from the head cg, which is almost double the 34 mm in football. A smaller radius in football prevents the helmets from sliding off each other in a tackle.
CONCLUSION: Olympic boxers deliver punches with high impact velocity but lower HIC and translational acceleration than in football impacts because of a lower effective punch mass. They cause proportionately more rotational acceleration than in football. Modeling shows that the greatest strain is in the midbrain late in the exposure, after the primary impact acceleration in boxing and football.
Mild Traumatic Brain Injury Committee, National Football League, New York, New York Sports Biomechanics Laboratory, Bioengineering Center, Wayne State University Detroit, Michigan, Pro Biomechanics LLC, Bloomfield Hills, Michigan (Viano)
Mild Traumatic Brain Injury Committee, National Football League New York, New York, Department of Neurology, Long Island Jewish Medical Center, New Hyde Park, New York, Department of Neurology, Albert Einstein College of Medicine, Bronx, New York (Casson)
Mild Traumatic Brain Injury Committee, National Football League New York, New York, ProHEALTH Care Associates, LLP, Lake Success, New York (Pellman)
Sports Biomechanics Laboratory, Bioengineering Center, Wayne State University Detroit, Michigan (Bir, Zhang, Sherman)
Safety and Equipment Committee, USA Boxing, US Marine Corp, United States Naval Reserves, Trauma Division, Hamilton Health Sciences, McMaster University Hamilton, Ontario, Canada (Boitano)
Reprint requests: David C. Viano, Dr. Med., Ph.D., ProBiomechanics LLC 265 Warrington Rd. Bloomfield Hills, MI 48304-2952. Email: email@example.com
Received, March 16, 2005.
Accepted, September 7, 2005.