Mechanics of Speed

MECHANICS OF SPEEDA SCIENCE-BASED APPROACH TO PRACTICAL IMPROVEMENTMike Young, PhDHPC - Athletic LabCary, NC USAVancouver Whitecaps FCVancouver, BC Canada

• Insight from today’s best • General concepts• Fundamental physics • Acceleration mechanics• Performance limiters • Top end speed mechanics

People Running Ridiculously Fast

6 99 .

9.6919.26

Lewis (1988) Bolt (2008) 0-10m 1.89 1.85 10-20m 1.07 1.02 20-30m 0.94 0.91 30-40m 0.89 0.87 40-50m 0.86 0.85 50-60m 0.83 0.82 60-70m 0.85 0.82 70-80m 0.85 0.82 80-90m 0.86 0.8390-100m 0.88 0.90 Time 9.92 9.69

Top Sprinters TODAYaccelerate Faster & Longer &DeceleratE Less

POINTS TO REMEMBER• Today’s top sprinters: • Accelerate faster and longer • Maintain top speed longer • Decelerate less• Improving mechanics will improve performance

Are you spending time worrying about things that aren’t based in reality?

INERTIAIt turns out Sir Isaac was right

WHAT LIMITSPERFORMANCE?

Research Review

•Gravity....u•We wor k gh•Excess ma to overc ome gra ss hur ts v ity perform ance

= more speed•More force le across speeds me is co mparab• Air ti imb spe ed....meh•L is KING •Ver ti cal force

lates with speed ide length corre•Str e is imp or tant• Horizo ntal forc

•Better sprinte r s are front-sidedominant Better sprinter s have shor ter•contact times Full extension neither needed • n or beneﬁcial Ideal touchdown characterized • by swin g knee even with suppor t knee

•CL more effective at a •CL produces higher re pplying force •CL velocity componen lative net horizon tal force •CL has shor ter contac t of F-V is higher •CL has higher stride fr t times equency eMaitre Insert research on French LCL = Christophe

ACCELERATION CHARACTERISTICS• Velocity @10m: ~8.2 m/s• Ground Contact Time: ~0.17 sec• Height of foot @ 1st step: 12-30cm• Stride Frequency: 3.6-4 Hz• Stride Lengths: ~1.5m ﬁrst step

MAXIMAL VELOCITY CHARACTERISTICS *Stride Frequency: ~5 Hz*Maximal Velocity: ~12.8 m/s *Stride Velocity: ~300 deg / sec *Stride Lengths: 2.25-2.7m*Ground Contact Time: ~0.08 sec*40-45 steps for sub 9.80 100m

KINETICPARAMETERS• Groundreaction forces approaching 3x bodyweight• Muscle forces in excess of 7x bodyweight

GENERALCONCEPTS OF SPRINTING by Hugo Faasta

N at ur eN ur tu re

Loren Seagrave

Sprinting fast is anunnatural activity Dr. Ralph Mann

MECHANICS OF SPRINTING• Sprinting well is a combination of nature and nurture• There are reﬂexive and innate components as well as trainable components

FRONT SIDE MECHANICS• Refers to the motions of the leg that occur IN FRONT of the body

BACK SIDE MECHANICS• Refersto the motions of the swing leg that occur BEHIND the body

Stride Length x Frequency = Speed?

B UT .. ..

CorrelationD O E S N OT i m p l yCausation

Old: To increase d, increa se stridespee quency New: Stri length and fre de length & frequency are inter- related an d an effec rather th t an a caus e

STRIDE LENGTH & FREQUENCY• Stridelength and frequency are linked...they are a consequence and not a cause of speed• Speedof movement of limbs is of little importance

STRIDE LENGTH & FREQUENCYThe beneﬁt of greater force application is two-fold:• Increased stride length • Increased stride frequency

SPRINT MATH• Stride frequency is comprised of two components: 1. Ground contact time 2. Flight time• The best sprinters spend less time on the ground ◦ Greater frequency

POINTS TO REMEMBER• Forces applied to the ground are the most important determinant of running speed • It increases stride length and frequency• Better sprinters apply more force in a shorter period of time

EXAMINING FORCE• Force is a vector quantity • Magnitude • Direction

FORCE DEVELOPMENT & SPRINTING• Toincrease running speed an athlete must increase force to the ground in the appropriate direction and do so over increasingly shorter periods of time • Minimize horizontal braking forces* • Increase propulsive forces

POSTURE

The first most important aspect of speed is posture.Tom Tellez

POSTURE• Movements of the limbs originate from the core of the body• Properstabilization and alignment of the core ensures appropriate movements of the limbs

POSTURE• Postural Stabilization• Postural Alignment • Relaxation • Freedom of movement • Elastic energy production

PELVIC MOTION• The pelvis should rotate in all three planes

Postural Test!

Posture during Acceleration NoNo

POSTURE DURING MAX VELOCITY

POSTURE DURING SPEED ENDURANCE

FOOT CONTACT...what it tells us

Acceleration Mechanics

Run fast For long

Run fast .

Run (accelerate)

Early Acceleration•Big split of arms & legs•Ipsilateral synchrony of leg & arm angles•Pushing through long axis of trunk•Hip, knee, ankle extension•Low heel recovery•Neutral posture

EFFICIENT BLOCK CLEARANCE

TOE DRAG,OR NOT TOE DRAG,THAT IS THEQUESTION...

Late Acceleration •Continuation of previous points •Progression of body angles •Stepping over calve ➟ knee

•Progression to upright •Shoulder - hip stackTRANSITION

Variable Early Late Contacts Longer ShorterSegment Usage Bigger Smaller Body Angle Forward UprightHeel Recovery Low Higher Leg Action Piston-like Cyclic GRADUAL progression is key

When does 60 = 20?

EXTENDING ACCELERATION• Staying in pushing mechanics permits a neuromuscular and metabolic shift that allows for less fatigue later in a race• Athletes should display: • Lower heel recovery • Gradual but slow progression of body angles • Piston-like action of the legs

city SprintingMaximal Velo

tim izingOp e ch an ics?M

Max V Sprinting 101 Big Force + Right Direction + Minimal Time Faster

GOALS OF SPRINTING• Minimize braking forces• Increase propulsive forces

MINIMIZE BRAKING FORCES• Decreases horizontal velocity• Caused by excessive step length and positive foot and leg speed at ground contact

EFFECTIVE GROUNDCONTACT POSITION

IncreasingPropulsive Forces

Horizontal vs Vertical Propulsive Forces.... and why you don’t have to pick a side

VERTICAL PROPULSIVE FORCE• Increasedvertical propulsive force produces: • Greater displacement • More effective ground contact position • Better maintenance of momentum

Am plit ude ?

Boing?

VERTICAL DISPLACEMENT• The path of COM will follow a sinusoidal curve when viewed in the sagittal plane • COM reaches apex in ﬂight • COM low point during support

To go faster, you needmore force. The more force you apply, thehigher you will rise off the ground. Charlie Francis

INCREASE LEG STIFFNESS• Refers of the ability of the leg to act as like a spring• Momentum is developed during acceleration• Body will move at same rate unless acted on by unbalanced forces• Two external forces will cause deceleration• Leg stiffness increases vertical impulse, shortens ground contact and increases elastic return

Better sprinters mayappear to bounce

Better sprinters may In reality, ﬂight times are similar andappear to bounce ground contact times are shorter

SPRINTMechanicsChecklist

PosturePosture Trunk Erect Head Level Hips Tall

Ground ContactUpright postureMinimize horizontaldistance between footand hipsLegs togetherHeel high

Stance PhaseUpright postureTall hipsVertical forcesSwing leg active

Stance PhaseUpright postureStepping over knee

Stance PhaseUpright postureHigh kneeSwing leg unfolds

Toe OffProjection of non-support hipHigh kneeNeutral / dorsiﬂexedankleMinimal backsidemechanics

FlightAppropriate verticaldisplacementPreparation forground contact Downward acceleration of thigh Neutral / dorsiﬂexed ankle

Max VelocityTechnical PointsFix postureEmphasize vertical pushes “Push up”High hips “Run tall”Step over and down

CLOSING POINTS• Performance breakthroughs can be made by accelerating faster & longer• Maintaining top speed means less speed endurance• Enhancement of mechanics will improve performance• Posture is key to performance

MIKE@ATHLETICLAB.COMTWITTER.COM/MIKEYOUNGATHLETICLAB.COMELITETRACK.COMHPCSPORT.COM THANKS

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Mechanics of Speed

by Mike Young on Jan 20, 2013

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