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biomechanics


Biomechanical focus

Salazar were mesmerised by the style of double world record-holder and Olympic champion Kenenisa Bekele.

After consulting multiple Olympic gold medallist Michael Johnson and staff at his performance centre, who measured the angles of Bekele’s arms and legs during his stride pattern, the realisation hit Salazar that Bekele had an arm action that was not dissimilar to that of a sprinter.

The rapid trail-leg retraction effected by sprinters enabled their running to

(a) generate more power and

(b) give the foot a shorter distance to travel before it arrived back ready to begin another stride, thus allowing for an increase in cadence and ultimately speed.

Salazar began to experiment with top US distance runner, Dathan Ritzenhein, who had finished ninth in the 2008 Beijing Olympic marathon and who parted with long-standing coach Brad Hudson in May 2009. Salazar noticed a range of biomechanical deficiencies with his newly acquired athlete and worked on effecting change with some of the following idiosyncrasies.

1. Heel striking

Video analysis showed that Ritzenhein was a heel striker who was overstriding with a resulting braking effect upon ground contact. This is caused by Newton’s third law of motion that states: “For every action, there is an equal and opposite reaction.” This means that if you overstride and heel strike, every time you hit the ground the reaction forces are therefore backwards and upwards, giving a braking effect instead of downwards and forwards.

In analysing Bekele, Salazar observed that by drawing his lower leg down and backward, and slightly pulling up the toe to a more neutral foot position, a positive acceleration could be achieved by minimising this braking effect and allowing for a much quicker transfer into the support and drive phase of the stride.

2. Foot placement

With the aid of Nike biomechanical expert Gordon Valiant, Salazar studied the loading patterns in terms of the amount of force being exerted on parts of the foot during impact. Salazar noted that Ritzenhein was placing his foot too far forward in front of his centre of mass, which was inefficient as the hamstring was having to work hard to pull the trunk of the body over the forefoot. By working on pulling the foot-strike closer to underneath the centre of mass, Salazar realised this would also decrease the braking effect described above.

3. Hips

Ritzenhein’s hips were seen to be relatively low compared to the “high hips” of the 11-time world senior cross country champion Bekele, which were carried directly under the body. Salazar became aware that high hips allows a longer stride length along with force to be more directly transferred up through legs, hips and upper body, effecting greater forward propulsion.

4. Elbow drive

In comparing Ritzenhein to the great Bekele, Salazar observed that the former had an elbow drive of approximately 60 degrees whereas the latter could generate more force by driving his elbows back in the region of 70 degrees. The drive of the arms backward balances the lower body forces, meaning that a greater, more forceful arm drive will balance more force being produced by the legs.

5. Hands

The level of attention to detail which Salazar gave to Ritzenhein was meticulous. It even stretched to him being challenged to drop his previously rigid upturned thumbs in favour of a more relaxed position on his index fingers.

Bringing about change

Notably the modification of Ritzenhein’s style has not been without problems and he has suffered injuries, but as Salazar himself acknowledged: “When you start changing an athlete’s form, there’s always a risk.” Since switching to Salazar, Ritzenhein finished sixth in the 2009 world championships 10,000m in a personal best of 27:22.28 and became only the third American in history to break the 13-minute barrier for 5000m in that same year. He also took a world half- marathon championship bronze in Birmingham in 60:00 and set a marathon PB of 2:07:47 in 2012.



It is possible for coaches to make evidence-based interventions to change the running style of their athletes to attempt to produce more economical, efficient and effective performance over a period of time.



The basic technical template for endurance:

» Tall posture with high hips.

» Relaxed shoulders with efficient backwards driving arm action.

» Rhythm guides optimal speed and efficiency.

» Foot lands naturally underneath the centre of mass, moving down and backwards.

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