Duceo Exactly as Received from the Person or Organization Origin Ating It Points of View or Opinioa Stated Do Not Necessarily Repre

Although the sport of karate has been somewhat neglected by scientists, the following two isolated biomechanical studies exist in literature: (1)-tracings of a karate chop in two planes were presented, but no data was given concerning the rates of movement of the limb segments, and (2) preand postimpact phenomena of five subjects were studied, and hand velocities and forces at impact were reported. This study attempts to provide additional data for the biomechanical analysis of the karate chop. An initial subjective analysis-of five subjects using film taken at 20,0 frames per second identified three fundamentally different patterns of movement. Films were also taken to analyze the kinetic aspects of the study; they show the various components contributing to the .accelerometer output.-The various unknowns can also be calculated from film giving an interesting comparison of direct and indirect methods of estimating acceleration. The study use the technique of accelometry to illustrate the differences in using preferred and nonpreferred handt to break boards. The accelometer recorded considerable differences during this experiment, and this technique may prove to be a useful teaching device which can provide immediate feedback. The study incorporates electromyographic results with kinematic and kinetic data to provide further insight into the movement to be obtained. Although the study is primarily=concerned with preimpact phenomena, it also makes very approximate estimates of the forces existing at impact. (BD) *********************************************************************** * 'Documents acquired by ERIC include many informal unpublished * materials not available from other sources. ERIC makes every effort * * to obtain the best copy available. Nevertheless, items of marginal * * reproducibility are often encountered and this affects .the quality * * of the microfiche and hardcopy reproductions ERIC makes available * * via the ERIC Document Reproduction Service (EDRS). EDRS is not * responsible for the quality of the original document. Reproductions * * supplied by EDRS are the best that can be made from the original. *********************************************************************** U 5 DEPARTMENT OF HEALTH, EDUCATION WELFARE NATIONAL INSTITUTE OF EDUCATION THIS DOCUMENT HAS BEEN REPRO DUCEO EXACTLY AS RECEIVED FROM THE PERSON OR ORGANIZATION ORIGIN ATING IT POINTS OF VIEW OR OPINIOA STATED DO NOT NECESSARILY REPRE -SENT-OFFICIAL NA T4ON AL-4NSTITUT-E OFEDUCATION POSITION OR POLICY 7777 A, 77 7' Ii8'1:16cha'AiC4111Ana ys 6 of -the Karate Chop Peter R. Cavanagh and Jean Landa Biomechanics Laboratory Penn State University University Park, Pa. The sport of karate has been somewhat neglected by sport scientists, who have directed their attention chiefly towards traumatology and conditioning of the hand. Two isolated biomechanical studies do exist in the literature. Plagenhoef (1971) presented tracings of a karate chop in two planes but gave no data concerning the rates of movement of the limb segments. He indicated the need to strike the blocks atright angles and estimated that a force in the region,of 875 lbs. was necessary to break the specimen used. Vos and Binkhor.st (1966) used Stroboscopic and strain gauge techniques to study pre and post impact phenomenaon five subjects breaking both bricks and blocks. Treating the problem in a linear manner, hand veloci'Aes from 28-31 mph were found in experienced subjects and forces at impact from 28-132 lbf were reported, although it is unclear exactly what these forces represent. Hirate (1971) reports studies by Kato of three subjects in which the maximum speeds in straight thrusts (presumably by the hand) reached 8.1 m/sec in the skilled and 5.3 m/sec in the unskilled performers. Speeds at impact were considerably less than these maxima and estimates of the forces at impact ranged A paper presented'at the 22nd annual meeting of the American College of Sports Medicine, New Orleans, Louisiana, 23 May 1975