LA84 Coaching Education Advanced Clinic Biomechanical Commonalities of the Horizontal Jumps

1. LA84 Coaching Education Advanced ClinicBiomechanical Commonalities of the Horizontal Jumps Cameron T. Gary Mater Dei Catholic H.S. – Chula Vista, CA USATF Level 2 - Jumps

2. Basic Jumping • How do we jump? • “Triple extension” of hip, knee and ankle joints • Fast & Coordinated • Until foot release • All three must happen in order to “jump” • “Summation of Forces” • Non-extension of any one joint makes the jump inefficient • VERY basic movement • Not “functional”, per se

3. Concentric Jumping • Main Characteristics • Pushing only • Strength-oriented • Overcome inertia - move from a stationary position • Body at rest tends to stay at rest… • Sprint starts • Beginning ofapproach run • We train this attribute through: • Bodyweight Exercises (e.g., Lunges) • Conventional weight lifting • squats, power cleans, snatches, dead lifts, etc. • Jumping up onto a surface • Running up stairs

4. Eccentric & Isometric Strength • Eccentric Contraction • Muscle lengthens under tension • Such as lowering the weight on a Bench Press • Stronger than Concentric • One can lower more weight than they can lift • Isometric (“isolate” + “measure”) • Muscle contraction w/o movement of joint • Very brief but very important • These attributes are trained by: • Lowering and/or holdingweight • “Farmer’s” Carry, etc. • Running/jumping then stopping (“Catching”) • Jumping down (“Sticking”) • Running downstairs

5. Pre-Recruitment • Increase tension before concentric contraction • Eccentric and Isometric • The resulting concentric contraction is stronger • Can utilize some of the muscle’s elastic properties • Analogous to stretching a rubber band • More Functional • Dorsi-Flexion of foot before planting • Cocking the arm for a punch

6. Basic Applied Skills • Full foot – the most basic skill a jumper must learn • The same for the Long Jump and Triple Jump • But not a “dead” foot • Dorsi-flexion enables pre-recruitment of muscles • Emphasize the middle of the foot striking the ground • Activates the larger muscles of the upper leg and hip • NOT heel first • NOT toe first • Deliver a Blow to the Runway/Board • “Pawing” – It may encourage dropping the toe (BE CAREFUL!) • Useful verbal cues: • Squish a bug • Break a board • Push a skateboard

7. Counter-Movement Jumping • Rapidweight drop • Temporarily “increase” weight • W/O increasing mass • Descent is briefly stopped • Quickly reversed • Isometric strength must be great • Arms increase force into the ground • Applied downward then upward • Body “lightens” as a result • Energy is “returned” to the body • Increased force into the ground = increased energy return to the body • Demo Basic CM Jump

8. Plyometric “Springy” Effect • Stretch-Shortening Cycle • RAPIDAbsorption > Stabilizing > Explosion • The FASTER the better • Focus on dynamic power (strength vs. time) • Develop functional tension (within reason) • Analogy: Bouncing rubber ball • The harder the ball, the higher the bounce • Maximum speed sprinting • Shallow knee angles – Fast ground contact • Multiple “jumps” down the track • One cannot “push” fast enough • Sinusoidal movement of pelvic girdle • “Horizontal” jumping really isn’t horizontal • Transitional vertical impulse – just like sprinting

9. “Loading” the Plyometric Spring • Foot strikes are active – “negative foot speed” • NEVER foot strike toe-down – common issues: • “Double hit” and/or foot “stammer” • Encourages reaching far ahead of the COM • Premature hinged-moment • This is what you do when you want to stop • Activates the smaller muscles – think “Proximal-Distal” • Be VERY careful with the so-called “B-Skip”! • Foot Dorsi-Flexion “loads” the Achilles tendon • Prepares calf/hamstring muscles for a stronger response • Be careful of how you drill • Anything worth doing is worth doing right • No point in practicing things that weaken athletic skills • You have to get down to get up • Dwight Phillips LJ video

10. Hinged-Moment Analogy • If you imagine a pogo stick w/ wheels, you understand the hinged-moment • This is what propels a pole-vaulter over the bar • However, there is stored energy in the flexible pole – same for muscles • Is what allows us to jump vertically while moving horizontally • The reason for the penultimate/pre-recruitment transition • Foot contact “checks” horizontal velocity - imparting forward rotation

11. Effect of Forward Rotation • The body rotates around the COM • Parabolic Path is Established at Takeoff • Can maximize or mess it up…but not extend it • Minimize excessive forward rotation • Utilize some forward rotation • Posture • Upright at take-off (neutral spine) • Upright during flight • NOT upright at landing • Feet land relative to body rotation around COM • Abdominal strength has NO effect on this

12. Horizontal Jump Objective • Project Center of Mass (COM) • As far as one can, from the board, into the pit • Path is determined at take-off • However – there is a constant battle vs. forward rotation • Optimal take-off angles – why? • 18 – 22 degrees – horizontal velocity is main contributor to distance • Project COM out, not up • COM starts from above the ground

13. Action-Reaction • Newton’s Laws… • Every action causes an equal and opposite reaction • Problem manifested – result of what precedes it • Arms relative to Torso • Set the pace/tempo • Rear Arm Sweep Example • Horizontal • Vertical • Legs relative to whole body (flight mechanics) • Same affect as the arms, but bigger • Hitch-Kick Effect • Legs push hips forward, arms push torso backward • Triple Jump Demo (Idowu)

14. Center of Mass • Mass is NOT weight • Mass is a function of matter • Weight is a function of the magnetic pull of mass toward the earth’s core • Earth vs. Moon • Body Positions re: COM • Standing • Bending • Front • Side • Arms play a role – DON’T forget them! • Relevant to the flight • Especially landing positions • Arms forward v. backward

15. Wall Test

16. Momentum (Mass x Velocity) – VERY Important • Start of approach - main attribute: strength/power • Top speed/end of run - main attribute: speed/reaction • Only necessary for horizontal jumpers to maintain high running velocities for 10 – 15 meters • Long interval running is not necessary (may be counterproductive) for jumpers! • Use short rest intervals to develop anaerobic power • However, jumpers must be able to run VERYfast! • But under control • Jumpers must convert horizontal to vertical QUICKLY • Skipping a stone on water – TJ • Delivering a blow to the board – LJ

17. Believe it or not… • It is possible to run even faster than sprinters at the end of the approach • Almost ALL jump distance is determined at take-off • The last few stridesof the approach determine take-off • In-Air movements only obtain optimal landing positions • Majority of training should focus on how to transfer the run into the jump

18. Can jumpers really run faster than sprinters in the approach? Edwards v. Conley • (1993 and 1995 World Championships) “Biomechanical Team’s Information Bulletins” • Conley is the faster sprinter, but as one can see – it is the speed over the last five meters that tells the tale

19. Summary & Questions

20. Cameron T. GaryUSATF Level 2 - Jumps www.ctgdevelopment.net 619-895-4699 jumpmaster@ctgdevelopment.net