The Block Start and Accerlartion Loren Seagrave Director of Track & Field and Cross Country Director of Speed and Movement
Phases of Acceleration (Linear) The Start Greatest Rate of Acceleration Pure Acceleration Slope of Acceleration Still Steep Transition Neuro-Mechanical Link to Vmax
Global Considerations of the Start and Acceleration Phases Force = Mass X Acceleration Force/Mass = Acceleration Limb Length Matters
Global Considerations-Start & Acceleration Sprinters Don t Have Jet Propulsion Inverse Relationship between Velocity and Ground Time Direct Relationship between Velocity and Air Time (with Limits) Contractile Power and Elastic Power Characteristics for Evaluation Big Force Short Time Proper Direction Optimal Range of Motion
The Start The Start is reaction time, force application and the first two steps, Speed Dynamics Sprint Training Volume 1 (circa 1989) spoken by Kevin O Donnell Don t Kick the Ball Drill Winning Drills for Women Bertucci and Crawford Stride Frequency is high at the beginning then increases, Speed Dynamics Sprint Volume 1
Sprint Start First Three Phases in the Sprint Race PURE ACCELERATION 15 meters 5 m IN OUT 20m 15m 20m PUSH-PUSH-PUSH Hip Extension- Acceleration TRANSITION 15 meters 5 m IN OUT 20m 35m 40m DRIVE TALLER Hip Extension-Max Velocity
Neuro-Biomechanics of Pure Acceleration Residual Phase Recovery Phase Transition Phase Ground Preparation Phase Front Side Ground Phase Backside Ground Phase
The Athlete s Mission Statement Reduce the Amount of Time Needed to Apply the Required Force into the Ground by 0.005 Seconds. Reduce the Amount of Time Needed to Recovery the Limb Through the Required Range of Motion by 0.005 Seconds.
Which Foot is on the Front Block? First Consideration for Block Placement Evaluation of the Start Action of World Class Female Sprinters Proceedings of the First IOC World Congress on Sport Sciences Colorado Springs 28 October-3 November 1989, 157. VAN COPPENOLLE H, DELECLUSE C, GORIS M, DIELS R, SEAGRAVE L, KRAAYENHOF H
Which Foot is on the Front Block? How is this best determined? First Consideration for Block Placement Fold your arms on your chest. (Johnson,B) Hop-Hop Start (Even Stance)
Second Consideration for Block Placement What is the Distance of the Front Pedal from Starting Line? Conventional Two Foot Lengths Maximum Distance (Santos, J) Knee on Line Foot Plantar Flexed
Third Consideration for Block Placement What is the Distance of the Rear Pedal from the Front Pedal? Front Pedal so Projection Angle is 90 Degrees to Surface of the Pedal Rear Pedal Between 30 or 35 Degrees and 45 Degrees (when lowest setting)
Preparation for Loading into the Starting Blocks Disappear inside a Phone Booth (Wells, T) The Argument for Dual Personalities in Sprint Start (Reardon, J) Increase of Neural Drive Ritual to Turn Light Bulb into Laser Beam - Coherent Entrainment (Kwai Chang Caine)
The On Your Marks Position Hand Position Hand Spacing and Alignment Hand Configuration Shoulder Position
The On Your Marks Position Foot Position May Vary With Block Pedal Height Medium Spacing, Equi-Distance Vertical Alignment of Feet & Thighs
The Set Position Front Knee Angle Approx 90 Degrees Rear Knee Angle between 120 & 140 Degrees Hips Higher than Shoulders Center of Mass Anterior to the Front Pedal Shoulders Above the Hands
Block Acceleration Synchronous Double Leg Force Summation of Hip and Back Extension Forces
Length of 1 st Step Length = Cos 45 X Xiphoid Height (Wells, T) Factors Determining 1 st Step Length Leg Length Muzzle Velocity Angle of Take Off Air Time
Mechanics of 1st Step Utilize Block Reaction Forces with Active Hip Flexor Action (Thigh Pops Forward) Foot Stays Low (Almost Drags) Ankle Dorsi-Flexed (Sole Down) Shin Angle More Vertical (ATM) Active Landing (NFS) Anticipatory Firing (Firm Foot) High Angular Acceleration @ Hip
Mechanics of 2 nd Step Maintain Step Length Over First Step Almost Identical Recovery Action Identical Air Time
Acceleration Pattern There is a regular acceleration pattern that gives optimal results (Winckler, G) The Rate of Incremental Increase is Athlete Dependent. Empirically the Highest Level Athletes Can Increase by 15% of Trochanteric Leg Length.
Pure Acceleration Phase Duration is about 2.0 Seconds For Top Level Sprinters about 15 meters (Tabachnik, B) Force is Generated Primarily by Muscle Contraction.
Transition Phase Serves as the Neuro-Mechanical Link between Acceleration and Vmax Duration to Reach 95% of Vmax for Elite is 4.5 to 5.0 Seconds Step Length Increases Asymptotically Toward Vmax Elastic Forces Predominate as Velocity Increases
Teaching and Coaching Pure Acceleration Wall Sprint Series - Neuro-muscular Resisted Acceleration Power Acceleration Ladder Neuro-muscular Contrast Training - Combination Assisted Acceleration Reactive Combo
Wall Sprint Series Stance Body Position Power Line Position Ankle Dorsiflexion
Wall Sprint Stance (Faults) Body Position Power Line Position Plantar Flexion
Wall Sprint Series Ready Position Knee Punch Forward Ankle Dorsi-flexed Sole of the Foot Down Toe Behind the Knee Shin Angles Parallel
Single Leg March Wall Sprint March Progression
Wall Sprint March Progression Alternate Leg March
One Count Wall Sprint Knee Punch Thigh Drive Body Position Ankle Cocked Shin Angle CONFIDENTIAL - Velocity Sports Performance Franchise Systems, LLC
Two Count Wall Sprint Knee Punch Thigh Drive Body Position Ankle Cocked Shin Angle
Three Count Wall Sprint Knee Punch Thigh Drive Body Position Ankle Cocked Shin Angle Avoid Butt Kicking
Rapid Fire Wall Sprint Knee Punch Thigh Drive Body Position Ankle Cocked Shin Angle
Harness Resisted Acceleration Resisted A-Run Acceleration
Bullet Belt Pop & Release Contrast Acceleration
Resisted Acceleration Options Face to Face Stance
Resisted Acceleration Options Face to Face A-Run
Face to Face Release Contrast Acceleration
Face and Chase Contrast Acceleration
Start Stance Acceleration Ladder
Execution Acceleration Ladder
Transition Phase Neuro-Biomechanics of Transition Neuro-mechanical link between pure acceleration and maximum velocity mechanics Common Faults Rush into maximum velocity too soon Stay in pure acceleration too long Drive Taller
Main Area of Training Concerns Technique: The Ability to Efficiently Run at a Wide Range of Pace Strength and Power: The Ability to Generate High Rate of Force Development Metabolic Fitness: All Appropriate Energy Systems are Developed to Genetic Potential. Energy Distribution: The Ability to Execute a Run Adjusting Under Varied Situations (Terrain, Weather, Pack Weight)