the biomechanics of punching
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
The Biomechanics of Punching
Vincent Bradbury Andrew Calogero
John FilostratCharles Henkel
Kevin HollyMary-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
Results: Accelerometer
Analysis: AccelerometerPunch # Improper 1 Improper 2 Proper 1 Proper 2
Impact Force N 249.393 272.3341 401.1037 251.5989
Results: Foot-Force Plates
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
Max Rx Max Ry Max Rz Max Lx Max Ly Max Lz
proper 1 30.20498 81.17479 556.361 131.8171 76.15867 544.8445
proper 2 77.16128 91.67496 495.637 117.624 63.17786 467.3839
improper 1 28.09289 71.6343 470.6215 95.60793 54.62115 590.1548
improper 2 26.21577 54.16175 566.4687 113.0273 101.229 607.615
Results: Video Analysis
Analysis: Video Analysis Initial velocity after the punch
Mgh=0.5mv^2 V=sqrt(2gd)
Distance traveled by the bag Arc length=( /360)2* *radius ,where is the θ π θ
angle in degrees
Trial delta t (s) Theta (degrees) scale (1:6") height, h (m) radius (m) arc (m) V1 (m/s)Improper 1 0.333 32 1.02245 0.103169 0.38612538 0.215543767 1.42273532Improper 2 0.367 54 1.0462 0.240118 0.414083909 0.390067043 2.17051035
Proper 1 0.3 46 1.10565 0.208773 0.457682579 0.367264843 2.0238889Proper 2 0.4 51 1.0462 0.243243 0.440678648 0.392057104 2.18458867
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