Wha

t You

Nee

d to

Kno

w A

bout

th

e Sp

rint S

tart

Ral

ph M

ann,

Ph.

DR

alph

Man

n, P

h.D

.. R

alph

Man

n, P

h.D

Ral

ph M

ann,

Ph.

D..

Bio

mec

hani

csB

iom

echa

nics

In

Mem

oriu

m

Jam

es H

ay

C. H

arm

on B

row

n B

ert L

yle

The

Goa

l G

et to

the

finis

h lin

e fir

st!

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

Gen

erat

e as

Muc

h Pr

oduc

tive

Forc

e as

G

ener

ate

as M

uch

Prod

uctiv

e Fo

rce

as

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Gen

erat

e as

Muc

h Pr

oduc

tive

Forc

e as

G

ener

ate

as M

uch

Prod

uctiv

e Fo

rce

as

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Gra

nd U

nific

atio

n Sp

rint T

heor

y

1.1.Fo

rce

Can

Onl

y B

e G

ener

ated

on

the

Gro

und

Forc

e C

an O

nly

Be

Gen

erat

ed o

n th

e G

roun

d 2.2.

Bod

y C

ente

r (C

OG

) Pos

ition

is C

ritic

al

Bod

y C

ente

r (C

OG

) Pos

ition

is C

ritic

al

Gen

erat

e as

Muc

h G

ener

ate

as M

uch

Prod

uctiv

ePr

oduc

tive

Forc

e as

Fo

rce

as

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Gen

erat

e as

Muc

h G

ener

ate

as M

uch

Prod

uctiv

ePr

oduc

tive

Forc

e as

Fo

rce

as

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Poss

ible

in a

s Litt

le T

ime

as P

ossi

ble

Gra

nd U

nific

atio

n Sp

rint T

heor

y

The

Vel

ocity

Pro

file

in th

e 10

0m

Sprin

t Per

form

ance

1

0 1 2 3 4 5 6 7 8 9 10

11

12 0

10

20

30

40

50

60

70

80

90

100

Dis

tanc

e (m

)

Velocity (m/sec)

Vm

ax

Hor

izon

tal V

eloc

ity P

rofil

e

THE

PHA

SES

OF

SPR

INTI

NG

Sprin

ting:

Hor

izon

tal V

eloc

ity

024681012

Velocity (meters/sec)

Hor

izon

tal V

eloc

ity

Sprin

ting:

Hor

izon

tal V

eloc

ity

024681012

Velocity (meters/sec)

Hor

izon

tal V

eloc

ity

St

art

Sprin

ting:

Hor

izon

tal V

eloc

ity

024681012

Velocity (meters/sec)

Hor

izon

tal V

eloc

ity

80

%

Star

t

Sprin

ting:

Hor

izon

tal V

eloc

ity

024681012

Velocity (meters/sec)

Hor

izon

tal V

eloc

ity

80

%

St

art

Tran

sitio

n

2

Sprin

ting:

Hor

izon

tal V

eloc

ity

024681012

Velocity (meters/sec)

Hor

izon

tal V

eloc

ity

80

%

St

art

Tran

sitio

n M

ax V

eloc

ity

The

Phas

es o

f Spr

intin

g �

Rea

ctio

n Ti

me

(gun

to fi

rst m

ovem

ent*

) �

Acc

eler

atio

n

a.

Sta

rt

1. T

wo

Leg

Driv

e

2. O

ne L

eg D

rive

3.

Firs

t Ste

p

4. S

econ

d St

ep

b. T

rans

ition

�

Max

imum

Vel

ocity

a.

Atta

in

b. M

aint

ain

The

Phas

es o

f Spr

intin

g �

Rea

ctio

n Ti

me

(gun

to fi

rst m

ovem

ent*

) �

Acc

eler

atio

n

a.

Sta

rt

1.

Tw

o Le

g D

rive

2.

One

Leg

Driv

e

3. F

irst S

tep

4.

Sec

ond

Step

b.

Tra

nsiti

on

�M

axim

um V

eloc

ity

a. A

ttain

b.

Mai

ntai

n

The

Phas

es o

f Spr

intin

g �

Rea

ctio

n Ti

me

(gun

to fi

rst m

ovem

ent*

) �

Acc

eler

atio

n

a.

Sta

rt

1.

Tw

o Le

g D

rive

2.

One

Leg

Driv

e

3. F

irst S

tep

4.

Sec

ond

Step

b.

Tra

nsiti

on

�M

axim

um V

eloc

ity

a. A

ttain

b.

Mai

ntai

n

Theo

ry D

evel

opm

ent

�R

esea

rch

Sinc

e 19

82 (U

SATF

Fun

ded)

�

Top

Sprin

ters

in C

ompe

titio

n �

Bio

mec

hani

cal/S

tatis

tical

Ana

lysi

s �

Scie

ntifi

c M

etho

d Em

ploy

ed

–O

pini

on

–H

ypot

hesi

s –

Theo

ry

�O

n-Tr

ack

App

licat

ion

Focu

s �

Sprin

ting

�10

0 M

eter

s �

Mal

e A

thle

tes

�St

art

�U

nder

stan

ding

the

Even

t

3

The

Star

t

?? S

econ

ds??

Sec

onds

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Intro

duct

ory

Que

stio

n: T

he S

tart

Set P

ositi

on

Firs

t Mov

emen

t

3 M

eter

Mar

k

Hea

d H

its L

ine

Slow

est:

1.02

sec

Fa

stes

t: 0

.72

sec

0.30

Sec

onds

to th

e 3

Met

er

0.30

Sec

onds

to th

e 3

Met

er

Mar

k (~

3 St

eps)

Mar

k (~

3 St

eps)

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Intro

duct

ory

Que

stio

n: T

he S

tart

Hor

izon

tal V

eloc

ity P

rofil

e

0 1 2 3 4 5 6 7 8 9 10

11

12 0

20

40

60

80

100

Vm

ax

V2n

d St

ep

4

Hor

izon

tal V

eloc

ity P

rofil

e

0 1 2 3 4 5 6 7 8 9 10

11

12 0

20

40

60

80

100

Vm

ax

V2n

d St

ep

Tim

e Lo

st ~

0.7

sec

0.30

Sec

onds

to th

e 3

Met

er

0.30

Sec

onds

to th

e 3

Met

er

Mar

k (~

3 St

eps)

+ 0

.70

Seco

nds

Mar

k (~

3 St

eps)

+ 0

.70

Seco

nds

to th

e 60

Met

er M

ark

to th

e 60

Met

er M

ark

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Diff

eren

ce B

etw

een

9.5

& 1

0.5

Intro

duct

ory

Que

stio

n: T

he S

tart

0.30

Sec

onds

to th

e 3

Met

er

0.30

Sec

onds

to th

e 3

Met

er

Mar

k (~

3 St

eps)

Mar

k (~

3 St

eps)

Diff

eren

ce B

etw

een

9.5

& 1

0.0

Diff

eren

ce B

etw

een

9.5

& 1

0.0

Diff

eren

ce B

etw

een

9.5

& 1

0.0

Diff

eren

ce B

etw

een

9.5

& 1

0.0

Intro

duct

ory

Que

stio

n: T

he S

tart

100

Met

ers M

en: S

tart

Mod

el-A

100

Met

ers M

en: S

tart

Mod

el-B

Set P

ositi

on

5

Two

Leg

Driv

e

Sing

le L

eg D

rive

Step

One

Step

Tw

o

A g

ener

al k

ey (1

) to

over

all s

prin

t sta

rt pe

rfor

man

ce is

to m

axim

ize

the

amou

nt o

f ava

ilabl

e fo

rce

prod

uctio

n.

Sprin

t Stre

ngth

Em

phas

is

Sprin

t Stre

ngth

Em

phas

is

Sta

rt Fo

rces

6

Hor

izon

tal V

eloc

ity

Expe

cted

Hor

izon

tal F

orce

H

oriz

onta

l Blo

ck F

orce

s

0

200

400

600

800

1000

1200

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

Horizontal Force (Newtons)

Tim

e (S

econ

ds)

Fron

t Leg

B

ack

Leg

200

Lbs

100

Lbs

0 L

bs

Hor

izon

tal B

lock

For

ces

0

200

400

600

800

1000

1200

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

Horizontal Force (Newtons)

Tim

e (S

econ

ds)

Fron

t Leg

B

ack

Leg

Tota

l

200

Lbs

100

Lbs

0 L

bs

Ver

tical

Vel

ocity

Ex

pect

ed V

ertic

al F

orce

Min

imal

7

0

200

400

600

800

1000

1200

0 0.

1 0.

2 0.

3

Vertical Force (Newtons)

Tim

e (S

econ

ds)

Fron

t Leg

B

ack

Leg

200

Lbs

100

Lbs

0 L

bs

Ver

tical

Blo

ck F

orce

s

Star

t Fo

r the

eac

h st

ep, t

he V

ertic

al V

eloc

ity C

hang

e (�

Vv)

is:

�Vv �

.94

m/s

ec

Verti

cal F

orce

= 7

7.5

kg *

�V

v /.1

50 se

c

Verti

cal F

orce

= 4

85 N

(110

lbs)

Verti

cal B

lock

For

ces

0

200

400

600

800

1000

1200

0 0.

1 0.

2 0.

3

Vertical Force (Newtons)

Tim

e (S

econ

ds)

Fron

t Leg

B

ack

Leg

Bot

h

200

Lbs

100

Lbs

0 L

bs

Ave

rage

Ver

tical

Blo

ck F

orce

s

The

Gra

vity

Pro

blem

St

art

The

verti

cal e

ffort

is st

ress

ed fu

rther

due

to

the

Gra

vity

Han

dica

p:

Rev

ised

Ver

tical

For

ce =

485

N +

750

N

Verti

cal F

orce

= 1

235

N (2

77 lb

s)

Verti

cal B

lock

For

ces

0

200

400

600

800

1000

1200

0 0.

1 0.

2 0.

3

Vertical Force (Newtons) Ti

me

(Sec

onds

)

Fron

t Leg

B

ack

Leg

Bot

h

200

Lbs

100

Lbs

0 L

bs

200

Lbs

Wei

ght

Ave

rage

Ver

tical

Blo

ck F

orce

s

8

Ph

ase

L

ater

al

Hor

izon

al

Verti

cal

Tot

al

Star

t

0 lb

s

205

lbs

277

lbs

35

0 lb

s Tr

ansi

tion

0 lb

s M

ax V

eloc

ity

0

lbs

5

0 lb

s 3

67 lb

s

370

lbs

Sprin

t For

ces

The

Rea

lity

The

Stre

ngth

/Mec

hani

cs P

robl

em

The

Stre

ngth

/Mec

hani

cs P

robl

em

A g

ener

al k

ey (2

) to

Star

t per

form

ance

im

prov

emen

t is t

o m

axim

ize

strid

e ra

te b

y m

inim

izin

g bo

th g

roun

d co

ntac

t tim

e an

d ai

r tim

e.

Star

t Tur

nove

r Em

phas

is

Star

t Tur

nove

r Em

phas

is

Met

hods

To

Incr

ease

Stri

de L

engt

h

�Ju

mp

high

er (i

ncre

ase

verti

cal v

eloc

ity a

nd a

ir tim

e)

�Ex

tend

farth

er a

t Tak

eoff

(inc

reas

e gr

ound

tim

e)

�R

each

farth

er a

t Tou

chdo

wn

(incr

ease

gro

und

time)

�

Run

fast

er (i

ncre

ase

horiz

onta

l vel

ocity

)

Strid

e R

ate

vs. S

tride

Len

gth

9

Met

hods

To

Incr

ease

Stri

de R

ate

�

Jum

p lo

wer

(dec

reas

e ve

rtica

l vel

ocity

and

air

time)

�

Exte

nd le

ss a

t Tak

eoff

(dec

reas

e gr

ound

tim

e)

�R

each

less

at T

ouch

dow

n (d

ecre

ase

grou

nd ti

me)

�

Pull

grou

nd le

g th

roug

h fa

ster

(de

crea

se g

roun

d tim

e)

Strid

e R

ate

vs. S

tride

Len

gth

Met

hods

To

Incr

ease

Stri

de R

ate

�

Jum

p lo

wer

(dec

reas

e ve

rtica

l vel

ocity

and

air

time)

�

Exte

nd le

ss a

t Tak

eoff

(dec

reas

e gr

ound

tim

e)

�R

each

less

at T

ouch

dow

n (d

ecre

ase

grou

nd ti

me)

�

Pull

grou

nd le

g th

roug

h fa

ster

(de

crea

se g

roun

d tim

e)

Met

hods

To

Incr

ease

Stri

de L

engt

h

�Ju

mp

high

er (i

ncre

ase

verti

cal v

eloc

ity a

nd a

ir tim

e)

�Ex

tend

farth

er a

t Tak

eoff

(incr

ease

gro

und

time)

�

Rea

ch fa

rther

at T

ouch

dow

n (in

crea

se g

roun

d tim

e)

�St

art f

aste

r (in

crea

se h

oriz

onta

l vel

ocity

)

Strid

e R

ate

vs. S

tride

Len

gth

Met

hods

To

Incr

ease

Stri

de R

ate

�

Jum

p lo

wer

(dec

reas

e ve

rtica

l vel

ocity

and

air

time)

�

Exte

nd le

ss a

t Tak

eoff

(dec

reas

e gr

ound

tim

e)

�R

each

less

at T

ouch

dow

n (d

ecre

ase

grou

nd ti

me)

�

Pull

grou

nd le

g th

roug

h fa

ster

(de

crea

se g

roun

d tim

e)

Met

hods

To

Incr

ease

Stri

de L

engt

h

�Ju

mp

high

er (i

ncre

ase

verti

cal v

eloc

ity a

nd a

ir tim

e)

�Ex

tend

farth

er a

t Tak

eoff

(incr

ease

gro

und

time)

�

Rea

ch fa

rther

at T

ouch

dow

n (in

crea

se g

roun

d tim

e)

�St

art f

aste

r (in

crea

se h

oriz

onta

l vel

ocity

)

Strid

e R

ate

vs. S

tride

Len

gth

Star

t: St

ride

Leng

th

0

0.51

1.52

2.5 Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9Step 10Step 11

Max Velocit

y

Stride Length (meters)

Step

Len

gth

Star

t: St

ride

Leng

th

0

0.51

1.52

2.5 Step 1

Step 2

Step 3

Step 4

Step 5

Step 6

Step 7

Step 8

Step 9Step 10Step 11

Max Velocit

y

Stride Length (meters)

Step

Len

gth

Goo

d

Bad

Star

t

Star

t: St

ride

Rat

e

012345

Stride Rate (steps/sec)

Stri

de R

ate

Goo

d

Bad

10

Star

t: St

ride

Rat

e

012345

Stride Rate (steps/sec)

Stri

de R

ate

Goo

d

Bad

St

art

Star

t: A

ir an

d G

roun

d Ti

me

0

0.050.

1

0.150.

2

0.250.

3

0.350.

4

Time (seconds)

Air

Gro

und

Star

t: A

ir an

d G

roun

d Ti

me

0

0.050.

1

0.150.

2

0.250.

3

0.350.

4

Time (seconds)

Air

Gro

und

St

art

How

Do

They

Do

It?

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

THE

MEC

HA

NIC

S O

F TH

E ST

AR

T Th

e G

olde

n St

art P

ositi

on

11

5.0

met

ers/

seco

nd

0.42

seco

nds f

rom

Sta

rt

0.5

met

ers St

ep O

ne: K

nee

Cro

ss

Spec

ific

Mec

hani

cs

Des

crip

tors

The

Star

t

Set P

ositi

on F

oot P

lace

men

t

60%

10

0%

-0.3

5

-0.3

-0.2

5

-0.2

Poor

Poor

Goo

d

Distance (m)

CO

G D

ista

nce

at S

tart

(m)

Set P

ositi

on A

ngle

s

12

Blo

ck C

lear

ance

Ang

les

Step

One

Pos

ition

s

Step

Tw

o Po

sitio

ns

The

Bre

akth

roug

h C

once

pt

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

Und

erst

andi

ng T

he S

prin

t Pe

rfor

man

ce

Prop

er sp

rint m

echa

nics

are

requ

ired

to g

et

the

mos

t out

of t

alen

t and

dev

elop

men

t. •

Max

imiz

e “F

ront

Sid

e M

echa

nics

” •

Min

imiz

e “B

ack

Side

Mec

hani

cs”

Sprin

t Mec

hani

cs D

eman

ds

Sprin

t Mec

hani

cs D

eman

ds

Sprin

t Mec

hani

cs D

eman

ds

Fron

t Sid

e Fr

ont S

ide

Bac

k Si

de

Bac

k Si

de

13

0

200

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14