The damaging punch.

Abstract

Subject and methods The mechanical properties of a boxing punch have been determined using several techniques. The results are consistent with the medical consequences ofboxing discussed in the report ofthe Board of Science and Education Working Party on boxing. Data were gathered from a world ranked British professional heavyweight, Frank Bruno, as he punched an instrumented, padded target mass suspended as a ballistic pendulum. Within 0-1 s ofthe start the punch had travelled 0-49 m and attained a velocity on impact of 8-9 m/s. The peak force on impact of 4096N (0.4 ton), attained within 14 ms of contact, represents a blow to the human head of up to 6320N (0-63 ton). The transmitted impulse generated an acceleration of 520 m/s2 (53 g) in the target head. For comparison an equivalent blow would be delivered by a padded wooden mallet with a mass of 6 kg (13 lbs) if swung at 20 mph. IntroductionThe BMA report on boxing identified two main causes of structural damage to the brain attributable to boxing': one, the cumulated effects of sustained exposure to the sport, the other, the acute and direct result of a severe blow. In the report emphasis was placed on the importance ofgathering "comprehensive, relevant medical data about all boxers and ex-boxers." This paper seeks to contribute to this database not on the medical issues as such but on the characteristics of the damaging blow that gives rise to the medical issues.Attempts to measure the physical properties of a boxer's punch have been reported. Baagreev and Trahimovitch used a three component accelerometer in the centre ofa boxing bag and a Kistler force plate fastened to the wall.2 Joch, Fritsche, and Krause used an elastic walled, water filled punch bag with a built in pressure gauge.3 Unterharnscheidt attached accelerometers to the heads of two inexperienced students and monitored them as they fought.4The above methods, although informative, are not without their drawbacks. Thus, for instance, an elastic walled bag does not provide a realistic time history offorces ofimpact on the head; a wall mounted force plate is a daunting target to punch even if gloves are worn; head mounted accelerometers trail leads, which inhibit movement, and it is unethical to hold these targets still to standardise measurement conditions; and untrained amateurs are unlikely to generate information that is relevant for the trained professional.This study, which seeks to determine the properties of the punch of a heavyweight professional boxer, overcomes many of the above disadvantages by combining several techniques of measurement. The scope of the work is limited to one subject, the highest rated heavyweight boxer in Britain, so, although generalisations cannot be applied to the boxing population, the results are ofvalue and will reflect the upper limits of forces to be expected from the boxing punch.

Single maximal versus combination punch kinematics

“…The mean contact speed for all subjects for the Single maximal Cross (8.22 ± 1.08 m/s) is comparable with previous studies which has been measured at 8.9 m/s for one professional boxer (Atha, et al, 1985) and 8.16 m/s for amateurs (Walilko, et al, 2005). Further, both Hook punches had significantly higher (P < 0.05) contact speed than the Straight punches confirming the findings of Whiting et al (1988).…”

“…Past research into punching in boxing has mainly focused on single punches with respect to its end-point (fist) speed and estimated impact force Page 3 of 22 delivered to a target. Single maximal punch contact speed has been measured at 8.9 m/s for one professional boxer (Atha, et al, 1985) and 8.16 m/s for amateurs (Walilko, et al, 2005). On both occasions fist displacement during punching was tracked from 2D optical camera images with a 3D accelerometer inserted into the glove of the boxer.…”

“…On both occasions fist displacement during punching was tracked from 2D optical camera images with a 3D accelerometer inserted into the glove of the boxer. This acceleration data was then mathematically integrated to confirm the velocity computed from the motion data (Atha, et al, 1985;Walilko, et al, 2005). Whiting et al (1988), using 3D optical motion analysis, reported that combination punches developed speeds of only 5.9 m/s.…”

“…This difference is also seen when comparing punch force. Impact force for a Single maximal boxing punch by elite boxers ranged between 3500 -4800 N (Atha, et al, 1985;Smith, et al, 2000;Walilko, et al, 2005). Punches in competition (in the ring) or simulated combination punches (in the laboratory) produce around half the impact force of Single maximal punches (Pierce, et al, 2006;Smith, 2006;Stojsih, et al, 2008).…”

Untitled

“…In his experiment he observed changes of the water level in a column from which he could derive the force of punch. (Atha et al, 1985) conducted an experiment where he measured the speed and the force of a punch of professional boxer Frank Bruno. The instrumental part of the device used in the experiment was a metal plate softened with felt and leather allowed moved on the shaft.…”