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The Biomechanics of Punching. Vincent Bradbury Andrew Calogero John Filostrat Charles Henkel Kevin Holly Mary-Anne Nguyen. Outline. Background Materials and Methods Accelerometer Foot-force plates Video Analysis Results Analysis Conclusion . Background.
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The Biomechanics of Punching Vincent Bradbury Andrew Calogero John Filostrat Charles Henkel Kevin Holly Mary-Anne Nguyen
Outline • Background • Materials and Methods • Accelerometer • Foot-force plates • Video Analysis • Results • Analysis • Conclusion
Background • Martial arts have been practiced for hundreds of years • The key to success in martial arts is to master proper techniques • Our study will provide a focus on the effectiveness of using proper technique while performing a rear-cross punch
Materials • Wood frame & sand bag • Accelerometer • Context Logger • Foot-Force Plate • Kistrel Piezoelectric Force Plates • BioWare Software Package • A-D hardware and Computer • Video Analysis • iPhone • Reflective body markers • Background length markers http://www.mobilewhack.com/wp-content/images/2009/02/iphone_video.jpg
Method • Proper technique • subject stood on the foot-force plates on the balls of his feet and front hip pointed toward the bag • Punching by twisting the hips and shoulders forward while pushing off of the back-foot to drive the fist forward • Improper technique • subject first stood on the foot-force plates with flat feet and hips facing the bag • Punched the bag with full force using his shoulder
Analysis: Foot Force Plates • Peak of the total ground force reaction was calculated by finding the instantaneous vector forces of the Fx, Fy, and Fz
Analysis: Video Analysis • Initial velocity after the punch • Mgh=0.5mv^2 • V=sqrt(2gd) • Distance traveled by the bag • Arc length=(θ/360)2*π*radius ,where θ is the angle in degrees
Conclusion • Accelerometer • Improper technique has an average force that is a bit lower than the average proper punch forces • Maximum improper force is actually greater than the minimum proper force • GRF that was observed during this strike may also show a smaller reaction for from the punch • Foot force plate • More twisting involved during the proper technique • Proper technique enhances the force available to give off in the x-y plane based on Newton’s third law of motion. • Video analysis • Video recorder captured each punch at an angle not perpendicular to the plane of action • Scaling every dimension to the six inch reference marking behind each shot • To reduce error in a hypothetical duplicate lab, a camera stand and highspeed camera faced directly into the plane of action