Positive running posture sums up the right technique for top speed

Transcription

1 Positive running, a model for high speed running Frans Bosch positive running posture sums up the right technique for top speed building blocks in running: Pelvic rotation for- and backward and hamstring function control of anterior-posterior pelvic rotation is crucial for hamstring function ground-reaction-force and the whip from the hip 2012 Positive running posture sums up the right technique for top speed

2 the worlds best sprinters run more positive posture than the also participating Building blocks in running: Pelvic rotation for- and backward and hamstring function Toe off pelvic rotation is controlled by positive running

3 arm-action vertical GRF positive running positive running negative running increasing forward rotation pelvis reduced scissors action foot placement in front of the hip big pendulum small pendulum

4 quick leg recovery The most difficult moment in the running-cycle ; reversing the pendulum right leg abdominals iliopsoas rectus right leg hamstrings erector gluteus F F L L

5 Control of anterior-posterior pelvic rotation is crucial for hamstring function

6 Energy in the running-cycle At high speed large quantities of energy are transported from one leg to the other by elastic stretch. (4-5 times per second) reversing the pendulum hamstring load scissors motion End of stance; low EMG activity hamstring load scissors motion

7 elastic/isometric muscle-work eccentric-concentric muscle-work reactive muscle-work plyometrics tendon compliance Simulation of Biceps Femoris Musculotendon Mechanics during the Swing Phase of Sprinting Thelen et all pre-stretch and slack weak relation between ROM and muscle stretch SLACK STRECH INACTIVE ACTIVE F L Anterior and posterior tilt of the pelvis plays a important role in making the Hamstring work in its optimum length.

8 the pelvis as a lever forward rotation of the pelvis eccentric force on hamstring Darryl G Thelen 2006 F L Anterior and posterior tilt of the pelvis plays a important role in making the Hamstring work in its optimum length. Iliopsoas is crucial in Hamstring load >> there is no such thing as an overactive iliospoas.

9 If at the end of stance the pelvis rotates forward to far, it will have to rotated back during the Hamstring loading phase. Resulting in loss of speed efficiency and increasing Hamstring injury risk Ground-reaction-force and the whip from the hip limitation for maximum speed a) applying force force direction mainly vertical horizontal component limited by relative speed of the ground short ground-contact b) leg motion extreme acceleration and deceleration of the legs

10 horizontal component relative ground speed limiting for horizontal component ±3 m/s ±10 m/s 0,09-0,11 sec direction of the translation joint rotation vertical component At higher speed => less vertical oscillation At higher speed => shorter contact times The problem for running faster is not just applying more force, but more force in shorter time.

11 The problem for running faster is not just applying more force, but more force in shorter time. Solution; Just paw back? We conclude that human runners reach faster top speeds not by repositioning their limbs more rapidly in the air but by applying greater support forces to the ground Weyand et al leg speed is not limiting ±10 m/s!! >>!in 0,1 sec >>!! ±0m/s Spring mass model is to simple to represent reality, because horizontal force application is left out The problem for running faster is not just applying more force, but more force in shorter time and in the right direction. Solution; Just more strength in the weight room? max strength is not limiting

12 The problem for running faster is not just applying more force, but more force in shorter time and in the right direction. Solution; preparing the status of the next stance leg before initial contact >> the whip from the hip hamstrings m. gastrocnemius The Whip from the Hip The results of this study emphasize the importance of pre-activity and the activity of the leg extensor muscles during the braking phase of running. Their activity is in many cases well above that recorded during maximal voluntary contractions, suggesting that such contractions cannot be used as an indicator of the full activation potential of human skeletal muscle. Thus, features of central programming and reflex regulation seem to differ between isometric maximal voluntary contractions and stretch shortening cycle exercises such as running Changes in muscle activity with increasing running speed HEIKKI KYROLAINEN, JANNE AVELA, & PAAVO V. KOMI

13 slack > time before elastic stretch regulating stiffness

14 Energy-transport during squat-jump more hamstring activity more rectus activity 1 Gluteus motor function 2 Hamstrings directing GRF 3 Rectus and gastrocnemius transporting energy to ground

15 energytransport slack

16 Energy transporting muscles Kangaroo => optimum build for energy-transport Human => poor build for energy-transport Angle between Femur and foot optimal for energy transport; a key for talent? CM direction GRF

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18 Footaction and vertical/horizontal GRF pretension next stanceleg Hamstring repositioning swingleg Energytransport hip to knee rotation to translation limitation many processes have to be synchronized impossible to communicate to athletes like this. we need a simple concept => the whip from the hip Hamstring directing GRF Energytransport knee to ankle load and unload timed to ground speed The timing of all these aspects has to be perfect to get optimum force and direction of force in stance. Getting the status of the to be stance-leg right prior to contact is complicated coordination. Status stance-leg prior to Initial Contact is key to short contact times. The whip from the hip technique provides that status. Spring in the step synchronized with energy-transport Spring in the step synchronized with energy-transport Toe up when bringing the foot to the ground and then push the forefoot into the ground hip >> knee >> ankle extension 54

19 Toe up when bringing the foot to the ground and then push the forefoot into the ground hip >> knee >> ankle extension 57

20 conclusion; whip from the hip technique helps applying force to the ground earlier in stance. whip from the hip is a pattern that can be applied in many movement patterns thanks for listening 2012