Dr. Peter McGinnis-The Pole Vault Puzzle-Putting the Pieces Together(Web)

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

The pole vault puzzlePutting the pieces togetherPeter M. McGinnisKinesiology Department SUNY Cortland peter.mcginnis@cortland.edu

Whats puzzling about the pole vault?Does a fast approach run guarantee a high vault? Is a free takeoff (or pre-jump) really better? Should a vaulter jump up at takeoff?

2012 Trials Super ClinicUSATF & VS Athletics June 26 Eugene

Whats puzzling about the pole vault?Should a vaulter land on the heel or ball of the takeoff foot? Is a double leg swing more effective? To row or not to row, that is the question?

Whats puzzling about the pole vault?When will Bubkas record be broken or will anyone ever break it? Finally - what can be done to make the event safer? Before we continue lets look at the history of the pole vault.

HistoryHow has the pole vault evolved?Record progression Athletes Equipmentpoles landing pits runway surfaces vault box

Wooden Pole Era (1800s)(heights less than 3.66 m ~ 120) Heavy wooden poles ~ ash, hickory Sod or turned over sod landing pits Grass or dirt runways No box ~ spike or tripod on end of pole

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Wooden Pole Era (1800s)

Bamboo Pole Era (1900-1945)(3.66 - 4.76 m ~ 120 157 3/4) Lighter bamboo polesbuilt in handgrips slightly flexible

Sawdust, sand, sod, or wood chip pits Cinder runways Vault boxes introduced

Bamboo Era1912 ~ 130

Bamboo Era1912 ~ 130 1927 ~ 140

Bamboo Era1912 ~ 130 1927 ~ 140

Bamboo Era1912 ~ 130 1927 ~ 140 1940 ~ 150 Cornelius Warmerdam 1942 157 3/4

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Steel Pole Era (1945-1960)(4.80 m ~ 159 1/4) Man-made steel poles Bags of shredded foam rubber introduced All-weather track surfaces introduced Metal boxes

Steel EraDon Bragg1959 159 1/4 1960 Olympic Champion Last world record set on steel pole

Fiberglass Era1962 160 1963 - 5.00 m 1963 170 1970 180 1972 - 5.50 m 1981 190 1985 - 6.00 m 1991 200

Fiberglass Era2000 Womens pole vault introduced in the Olympic Games

Fiberglass Pole Era (1960-?)(4.83 - 6.15 m 1510 1/4 202)

Fiberglass Pole Era (1960-?)(4.83 - 6.15 m ~ 1510 1/4 202)

Light and flexible fiberglass poles

1986 Nordic Sport introduces pole with carbon fiber Gill Athletics is now the largest manufacturer of carbon/fiberglass poles

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Fiberglass Pole Era (1960-?)(4.83 - 6.15 m ~ 1510 1/4 202)

Fiberglass Pole Era (1960-?)(4.83 - 6.15 m ~ 1510 1/4 202)

Larger latticed foam pits (1984)

Larger latticed foam pits (2008)

Fiberglass Pole Era (1960-?)(4.83 - 6.15 m ~ 1510 1/4 202)

Performance progressionBubka Warmerdam fiberglass

Light and flexible fiberglass poles Larger latticed foam rubber pits All-weather runways Vault box modified to accomodate pole bend

bamboo steel wood

Strategy for solving the pole vault puzzle Empirical data Theory Simulation Experience

Basic pole vault mechanicsSimple pole model Based on work and energy Total energy at takeoff = Total energy at maximum height + work done

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Work and EnergyKinetic Energy (KE) = 1/2 mv2 + 1/2 I2 energy due to motion Potential Energy (PE) = Wh = mgh energy due to height Strain Energy (SE) = 1/2 kx2 energy due to elastic deformation (stretching, bending)

Work and EnergyWork = U = F d Work done by a force = average force x displacement along the line of action of the force Work (angular) = T

Work and EnergyIf energy were conserved Ef = EiEf = Final energyTotal energy of vaulter and pole at maximum height

Work and EnergyBut vaulter can add energy by doing work on the pole

Ef = Ei + UU = Work done by vaulter from take off to max. height

Ei = Initial energyTotal energy of vaulter and pole at takeoff

Work and EnergyHowever energy losses occur during pole bending, unbending, inelastic stretching, etc

Work and EnergyTotal Energy at Takeoff ~ Ei Ei = PEi + KEi + SEi PEi = Potential energy (cg height) KEi = Kinetic energy (velocity) SEi = Strain energy (pole bend)

Ef = Ei + U - ElostElost = Total energy lost during vault Final energy = initial energy + work done - energy lost

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Work and EnergyTotal Energy at Maximum Height ~ Ef Ef = PEf + KEf PEf = Potential energy (cg height) KEf = Kinetic energy at max. height

Work and EnergyFinal energy = initial energy + work done - energy lost

Ef = Ei + U - Elost[PEf + KEf] = [PEi + KEi + SEi] + U - Elost PEf = [PEi + KEi + SEi] + U - Elost - KEf

Work and EnergyPEf = [PEi + KEi + SEi] + U - Elost - KEftakeoff on pole

Work and EnergyMAX HEIGHT OF CENTER OF GRAVITY

Potential EnergyTAKEOFF

=ON POLE MAX HEIGHT

Potential + Kinetic + Strain + Work - Energy - Kinetic Energy Energy Energy Done Lost Energy

Maximize positive elementsPotential energy at takeoff ~ mgh Kinetic energy at takeoff ~ 1/2 mv2 Work done on pole ~ Fd + T(Any strain energy at takeoff will decrease KE at takeoff, so strain energy at takeoff should not be maximized)

Minimize negative elementsEnergy losses Kinetic energy at maximum height

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Energy LossesOccur during energy transfers and transformationsDuring takeoff During pole bending phase During pole straightening phase

Energy Transformations

Schade, Brggemann, Isolehto, Komi, & Arampatzis (2006)

Energy Transformationsenergy gain

Energy Transformationsenergy gain

Schade, Brggemann, Isolehto, Komi, & Arampatzis (2006)

Schade, Brggemann, Isolehto, Komi, & Arampatzis (2006)

Components of a 6 m vault1.25 m ~ height at takeoff 1.24 m ~ work done by vaulter + 3.51 m ~ takeoff velocity 6.00 m vault

Components of a 6 m vault

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Vaulter Characteristics Tall and lean

Vaulter Characteristics Tall and lean Fast

Vaulter Characteristics Tall and lean Fast Experienced

Vaulter Characteristics Tall and lean Fast Experienced Patient

Vaulter Characteristics Tall and lean Fast Experienced Patient Smart

Vaulter Characteristics Tall and lean Fast Experienced Patient Smart Passionate about pole vaulting

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Approach RunFast run Accurate run

Approach Run: Velocity A fast take off velocity depends on a fast approach run velocity.

Approach Run: VelocityMEN

Approach Run: VelocityWOMEN

Approach Run: VelocityMEN

Approach Run: VelocityRegression equation:Men: h = 0.61v - 0.085 Women: h = 0.87v - 2.73

WOMEN

h = predicted crossbar height cleared v = approach run velocity at takeoff For height in meters and velocity in meters per second

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Approach Run: VelocityMEN

Approach Run: VelocityMEN

Approach Run: VelocityMEN

Approach Run: VelocityVelocity over last 5 m of approach run is strongly correlated with crossbar height cleared (r = 0.77 for men, r = 0.83 for women)

Approach Run: Velocity10.00 m/s Scott Huffman (5.86 m, 1994) 9.84 m/s Sergey Bubka (5.85 m, 1993) Dean Starkey (5.70 m, 1994) Greg Duplantis (5.70 m, 1996) Jeff Hartwig (5.85 m, 1998)

Approach Run: Velocity8.96 m/s Stacy Dragila (4.20 m, 2001) 8.77 m/s Jenn Stuczynski (4.92 m, 2008) 8.62 m/s Lacy Janson (4.40 m, 2008)

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Approach Run: VelocityDoes a fast approach run guarantee a high vault? Noyou must be fast to vault high. but just because you are fast does not mean you will vault high.

Approach Run: Velocity The effectiveness of a vaulters technique - how much work he or she does during the vault - largely determines the difference in height achieved by two vaulters with the same velocity. As technique effectiveness decreases - the proportion of vault height accounted for by velocity increases.

Approach RunMinimize forces needed to carry pole by using pole drop technique

Approach Run pole push?Minimize forces needed to carry pole by pushing the pole?

Approach Run: Accuracy

Approach Run: Accuracy

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Approach Run: Accuracy

Approach Run: Accuracy

Approach Run: AccuracyMost vaulters use a visual control strategy to correct errors in the approach run. Corrections begin at the start of the 4th to last step before takeoff (the 5th to last support phase). Coaches checkmarks should be placed at this step or at the start of the 5th or 6th to last steps.

Approach Run: Accuracy

Approach Run: AccuracyUse a checkmark at the start of the 5th or 6th to last step.

Pole Plant: InitiationPole horizontal Right hand above hip Maintain good sprint mechanics Begins with left foot touchdown

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2012 TRIALS SUPERCLINIC Dr. Peter McGinnis

Pole Plant: 2nd to last stepSlightly longer than previous steps

Pole Plant: Last stepRight hand head high Left hand forward, shoulder high Upright posture

Pole Plant: Last step takeoffRight hand head high or higher Left hand forward and head high Upright posture

Pole Plant: Last stepUpright posture Low knee drive Shorter, quicker step

Takeoff Foot TouchdownMinimize energy losses Right arm fully extended upward Upright posture

Takeoff Foot TouchdownMinimize energy losses due to braking Avoid reaching a