The problem

Coaches have a qualitative method based on experience for assessing their divers during a performance. A springboard model provides a quantitative method and a better understanding of what is exactly happening during this first part of the dive. A combination of qualitative and quantitative methods provides coaches and divers the opportunity to produce the best results.

For example, coaches know if a diver has performed a good or a bad dive. By comparing coaches’ knowledge with the model outputs it could be possible to see why exactly that performance is better or worse.

“It has been a great experience being able to take my research and contextualise it with actual diving coaches as Adam Sotheran. I believe I will be able to use the developed model to improve the research in my PhD which will use sensors to inform models such as the ones developed here. I now feel better prepared for dealing with complicated mechanical models, for this I am grateful to Sheffield Hallam University and British Swimming for providing me with the opportunity and support I required these last six months,” said intern Jose Luis Gomez Esteve, Sheffield Hallam University.

The approach

Currently, several types of springboards can be found in the market [4]. It was decided to study and model ‘Maxiflex Model B’ because this one is used in the official diving competitions and it was possible to make experiments with them at Pond’s Forge International Swimming Pool in Sheffield.

Two different approaches were taken for developing the springboard model. The first was based on developing second order systems with 3 parameters: stiffness, equivalent mass and damping coefficient [1, 2, 3]. The second was based on developing a bidimensional finite element model using the geometrical and material properties of the springboard [1].

In order to calculate and validate the models, experimental data was required and experiments were carried out using a ‘Maxiflex Model B’ in the dry facility at Pond’s forge.

A Phantom v4 high speed video was used to film the experiments and an auto tracker system was developed to collect the required springboard positions. Data was used for calculating parameters in the first model and for validating the second one. Both models were developed using Matlab, Simulink and SimMechanics [5].

References

[1] Sprigings, E.J., Stilling, D.S. and Watson, L.G. (1989) Development of a Model to Represent an Aluminium Springboard in Diving. International Journal of Sport Biomechanics, 1989, 5,297-307
[2] Sprigings, E.J., Stilling, D.S., Watson, L.G. and Dorotich, P.D. (1990) Measurement of the Modelling Parameters for a Maxiflex B Springboard. International Journal of Sport Biomechanics, 1990, 6,325-335
[3] Miller, D.I. and Jones, I.C. (1999) Characteristics of maxiflex® model B springboards revisited. Research Quarterly for Exercises and Sport; 70, 4, pag 395
[4] http://www.duraflexinternational.com
[5] http://www.mathworks.co.uk