KINEMATICS OF MARTIAL
ARTS PUNCHES
Vishal Dasari | BIOL 438 | 4/19/12
Karate History
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Karate: “Empty Hand”
Originated in Okinawa, Japan
Shitoryu (1928)
 Gojuryu (1930)
Rotational Punch
 Shotokan (1938)
 Wadoryu (1939)
 Isshinryu (1956) - Vertical Punch
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Vertical Punch thought to be faster, but less powerful.
Introduction
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Four kinds of punches studied
 Traditional
Rotational Punch
 Late Rotation Punch
 Isshinryu Style Vertical Punch
 Recoil
 Vertical

to keep elbows in for guard and follow-up
Punch without Style’s recoil
Which is faster? Which is more powerful? Why?
Traditional Rotational Punch HSCam
Traditional Rotational Punch (Fist)
•Fist Maximum Velocity reached BEFORE impact. As muscles extend, fist impact at lower velocity.
Traditional Rotational Punch (Ball)
•Ball reaches Maximum Velocity as it leaves Fist Contact
•Time period of Ball deformation when Fist is in contact with ball as arm extends fully
•Velocity of fist dropping as arm extends
Traditional Rotational Punch (Calc)

Fist Maximum Horizontal Velocity: 8.611m/s
 19.26

miles per hour
Ball Maximum Horizontal Velocity: 10.052m/s
 22.49mph

Ball Horizontal Kinetic Energy Change:
 0J


| F=ma | (10.052/0.028)(0.45)=161.55N
– {(0.5)*(10.052m/s)^2*(0.45kg)}J = 22.735J
Time Span: just before impact – immediately following loss
of contact: 0.3640sec – 0.3920sec = 0.028sec
Concluded Power of Punch = 22.735/0.028 = 811.96W
•Assumed that Vertical Velocity/Kinetic Energy are inapplicable to question of Power.
Late Rotation Punch HSCam
Late Rotation Punch (Fist)
•Fist Maximum Velocity reached BEFORE impact. As muscles extend, fist impact at lower velocity.
Late Rotation Punch (Ball)
•Ball reaches Maximum Velocity as it leaves Fist Contact
•Time period of Ball deformation when Fist is in contact with ball as arm extends fully
•Velocity of fist dropping as arm extends
Late Rotation Punch (Calc)

Fist Maximum Horizontal Velocity: 8.706m/s
 19.48

miles per hour
Ball Maximum Horizontal Velocity: 10.960m/s
 24.52mph

Ball Horizontal Kinetic Energy Change:
 0J


| F=ma | (10.960/0.028)(0.45)=176.14N
– {(0.5)*(10.960m/s)^2*(0.45kg)}J = 27.027J
Time Span: just before impact – immediately following loss
of contact: 1.464sec – 1.4920sec = 0.028sec
Concluded Power of Punch = 27.027/0.028 = 965.25W
•Assumed that Vertical Velocity/Kinetic Energy are inapplicable to question of Power.
Isshinryu Style Vertical Punch HSCam
Isshinryu Vertical Punch (Fist)
•Fist Maximum Velocity reached AT impact. Vertical Punch has longer reach due to bent wrist, forward lean.
•Strike is at top of ball, Force lost through topspin. Could contribute to inaccurate calculation of
ball horizontal velocity/KE and therefore Punch Power.
Isshinryu Vertical Punch (Ball)
•Ball reaches Maximum Velocity as it leaves Fist Contact
•Time period of Ball deformation when Fist is in contact with ball as arm extends fully
•Velocity of fist dropping as arm extends
Isshinryu Vertical Punch (Calc)

Fist Maximum Horizontal Velocity: 7.497m/s
 16.77

miles per hour
Ball Maximum Horizontal Velocity: 9.567m/s
 21.40mph

Ball Horizontal Kinetic Energy Change:
 0J


| F=ma | (9.567/0.02)(0.45)=215.26N
– {(0.5)*(9.567m/s)^2*(0.45kg)}J = 20.594J
Time Span: just before impact – immediately following loss
of contact: 0.632sec – 0.652sec = 0.020sec
Concluded Power of Punch = 20.594/0.020 = 1029.7W
•Assumed that Vertical Velocity/Kinetic Energy are inapplicable to question of Power.
Vertical Punch w/o Recoil HSCam
Vertical No Recoil Punch (Fist)
•Fist Maximum Velocity reached JUST before impact. Vertical Punch has longer reach due to bent wrist,
forward lean. I was standing slightly further back than usual, so impact came at lower velocity.
•Strike is at top of ball, Force lost through topspin. Could contribute to inaccurate calculation of
ball horizontal velocity/KE and therefore Punch Power.
Vertical No Recoil Punch (Ball)
•Ball reaches Maximum Velocity as it leaves Fist Contact
•Time period of Ball deformation when Fist is in contact with ball as arm extends fully
•Velocity of fist dropping as arm extends
Vertical No Recoil Punch (Calc)

Fist Maximum Horizontal Velocity: 7.950m/s
 17.78

miles per hour
Ball Maximum Horizontal Velocity: 10.676m/s
 23.88mph

Ball Horizontal Kinetic Energy Change:
 0J


| F=ma | (10.676/0.02)(0.45)=240.21N
– {(0.5)*(10.676m/s)^2*(0.45kg)}J = 25.645J
Time Span: just before impact – immediately following loss
of contact: 0.536sec – 0.556sec = 0.020sec
Concluded Power of Punch = 25.645/0.020 = 1282.25W
•Assumed that Vertical Velocity/Kinetic Energy are inapplicable to question of Power.
Results from HSCam Study

Horizontal Punch is faster.
Conclusion of speed is under assumption that distance
moved by both punches is equal, which is false.
 Rotational Punch has a greater distance to move, but
movement incorporates more hip rotation. Therefore,
maximum horizontal velocity might be greater, but time
taken to go from hip to Point of Impact (POI) may be closer
to that of the Vertical Punch.
 Vertical Punch has shorter distance to move. Inability to
incorporate as much hip rotation into movement significantly
affects maximum horizontal velocity, but time from hip to
POI needs to be measured for both punches.

Results from HSCam Study

Vertical Punch is more Powerful.
The Vertical Punch spends less time in contact with the Ball,
reducing the time over which the Ball’s Horizontal KE is
increased. This shows as an increased Power output upon
impact.
 The Horizontal Punch spends more time in contact with the
Ball, a longer time over which the Ball’s Horizontal KE is
increased. This shows as a lower Power output upon impact.
 Horizontal Punch’s longer fist-contact may be attributed to
fist-rotation, which causes Ball deformation in more than the
x direction of movement, causing spin which again
contributes to a longer fist-contact period.

Results from HSCam Study

Vertical Punch is more Powerful.
 Force
of Impact calculations are shown to be
proportional to Power calculations, but this is due to
lack of appropriate measurement methods.
 Instantaneous Force must be measured; Ball
deformation makes it impossible to do this because Fist
is still in contact with and imparting energy to the Ball
after first impact.
 However, using derivative function, attempted to
calculate instantaneous acceleration, to use in F=ma.
Traditional Rotational Punch (Force)
F=ma | (0.45kg)*(597.34m/s/s)=268.803N
Late Rotation Punch (Force)
F=ma | (0.45kg)*(688.39m/s/s)=309.78N
Isshinryu Vertical Punch (Force)
F=ma | (0.45kg)*(494.26m/s/s)=222.42N
Vertical No Recoil Punch (Force)
F=ma | (0.45kg)*(622.64m/s/s)=280.19N
Results from HSCam Study

Late Rotation Punch impact with most force.
Improved calculations for instantaneous acceleration of the
ball immediately following fist-impact allow calculation of
instantaneous force, the ideally theoretical force that would
be dealt to a target with that punch (not ideal in real life,
but carrying on).
 These calculations show that the Late Rotation punch is the
most powerful*, most likely due to the addition of force
towards the end of the punch due to the last minute fast
rotation at the wrist.
 Next is the No Recoil Vertical Punch, the Traditional
Rotational Punch, and finally the Isshinryu Punch. Makes
sense as Isshinryu punch requires recoil, preparation for
which demands preemptive slowing down of the punch
slightly before impact, resulting in lower force.

HSCam Conclusions


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Late Rotation Punch hits with greater Force.
Vertical No Recoil Punch is most Powerful.
Late Rotation Punch is Fastest.


Not possible with current set up to measure time taken to
move from hip to POI, which should be considered the real
measure of “punching speed”, not maximum horizontal
velocity of the fist.
Temptation to hypothesize that Isshinryu Punch would be
“fastest” in above regard, because recoil preemptively
relaxes the arm in preparation for the next strike.
Should HSCam study punches for repeating strikes also.
TRP: 0.224sec; LRP: 0.216sec; IsVP: 0.207ec; NRVP: 0.204sec -- hip to POI times (!)
Thank you! And if we have time…
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Questions?
Thank you!
MoCap analysis of the punches, and how force
plate vector changes show Weight Shifting during
punches.
MoCap offers a more clear, multidimensional view
of the punching movement. Can be slowed to
1/10th speed to study movement in detail.
Motion Capture Analysis
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
Show MoCap Animations.
Compare to Excel sheets and show force plate
vector changes indicating weight shifting during
movement. Highlight forward weight shift during
Vertical Punches.