Who am I?

2. Who am I? • Name: Huw Roch • Occupation: DPS Student Sports Technology, Loughborough University

3. Real Life Technology Stories

4. Javelin

5. Problem • Legitimacy of landings in dispute • Safety issues due to increasing throw distances

6. Solution • Decrease flight distance • Bring nose down to ensure it hits the ground first.

7. How? • Flight distance needs to be reduced • Decreasing the pitching moment will bring the nose down • This will shorten flight length and increase the likelihood of the nose sticking in the ground

8. Action Taken

9. Action Taken • The easiest way to change the pitching moment is to move the centre of gravity away from the centre of pressure (this is where aerodynamic forces of life and drag act). • In 1986 the centre of gravity of the male javelin was moved 4cm forwards and in 1999 a similar action was taken on the female javelin.

10. Result • This had a significant effect of the length of the flight and can be clearly seen in the record throw lengths for each year.

11. Result

12. Golf

13. Problem • Players gaining a unfair advantage due to technological advancement • Courses becoming to short due to equipment development

14. Ping Eye2 Irons • These clubs create an unfair advantage due to U-grooves on the face • The square shaped grooves allow a very large amount of spin to be imparted on the ball, this helps to stop the ball on the green

15. Club Face Trampoline Effect • Recently clubs started to be developed with a face that allow a deformation followed by a quick restoration to its original dimensions • This acts like a slingshot on the ball creating a large ball speed allowing extremely long tee shots • Many courses simply are not long enough to provide a challenge if the clubs have this capability

16. Solution • Rules need to be developed to ensure unfair advantages are not gained and to prevent the need for major development across most golf courses

17. How? • Regulate coefficient of restitution properties of club/ball • Create rules regulating shape of groves in the club face

18. Action Taken

19. Action Taken • In 1998 a rule was placed stating that the coefficient of restitution between ball and clubface can not exceed 0.83.

20. Action Taken • Rules on club face/ball coefficient of restitution to prevent large trampoline effect having a sling shot effect on the ball • Square groves on the club face are banned as they allow an unfair level of spin to be imparted on the ball

21. Football

22. Problem • Identical kicks of a ball can create different deformations and therefore rebound effects depending on the orientation of the ball

23. Solution • Reduce the difference in stiffness between stitches and the centre of the panels • Account for material bias

24. Material Bias Material Bias

25. How? • Create new techniques to bond ball panels without creating areas with differing stiffness properties • Find a way to arrange the material in the panels to find the optimum

26. Action Taken

27. Action Taken • Adidas created a new technique for binding the panels of their balls using thermal bonding. This removes the need for stitching creating a much more even material stiffness across the surface of the ball. • An mathematical model was also created which optimises each panel’s orientation with regards to those around it to balance out the warp/weft characteristics of each

28. Sprint Shoes

29. Sprint Shoes Investigation • Recently the Sports Technology Institute has been involved in looking into the opportunities to improve athletic sprint performance by customising the soles of an athletes shoes. • It has been hypothesised that personally customised sole stiffness properties can improve an athletes performance.

30. Basic Principle • The basic principles that this study is using are that the stiffer the sole of the shoe the less energy is absorbed by the shoe and also that a stiffer sole will create a more efficient lever (by moving the centre of pressure)

31. Basic Principle

32. Testing • To test the theory of shoe customisation a variety of sprint shoes were created with rapidly manufactured soles attached. Each sole was a different thickness to vary the stiffness property. • Various tests were carried out including a variety of jump tests to calculate the impulse generated with each shoe.

33. Jump Test Model

34. Results Example • These are the results from a subject doing a squat jump with different stiffness soles being worn. (Shoes become stiffer A-F with F the most stiff)

35. Simply make the soles stiffer? • It seems logical that the companies who manufacture sprint spikes should just increase their shoe’s stiffness to improve performance • However sole stiffness is optimal at a different point for every sprinter. • The stiffer sole requires more energy generation at the ankle. • It also may require the sprinter to adapt their technique. • Finding the balance is key

36. Conclusions Made • The conclusion that was made was this: Sprint shoes that have soles of a customised stiffness optimised for an athlete can improve performance. However it requires two way customisation, shoe to athlete and athlete to shoe.

37. Your Turn....