Design and evaluation of sound-based electronic football soccer training system for visually impaired athletes

Abstract

Background: Several countries encourage the practice of football for rehabilitation and social inclusion purposes. For visually impaired people, football is purely sound-based, where the ball and the players are constantly emitting sounds for localization purposes in the field. However, the task of shooting the ball requires of a non-visually impaired extra person, behind the goal (known as caller), whom is punching the four corner of such goal to help the athletes. The presence of the caller restricts the self-sufficiency of the players. This work addresses such problem, by presenting a goal for visually impaired players with the aim of enhancing their self-sufficiency.

Materials and methods: The electronic goal is designed with four functionalities for training purposes, by returning sound-based feedback of its position and the places where the ball has impacted. The system is validated with seven volunteers from Chilean Football Soccer National Team. A questionnaire was answered by the players before and after the tests to statically validate the proposed device.

Results: The presented system is portable and designed following a modular criterion suitable for visually impaired people self-assembling. From a test of 350 shootings, the electronic goal showed to enhance the shooting assertiveness from 82 to 92%, and the accuracy from 20 to 56% compared to the traditional caller.

Conclusions: The electronic goal showed to enhance the self-sufficiency of athletes, by improving their assertiveness in shooting training. Nevertheless, and according to the responses to the questionnaires, the system needs improvements in its portability and handling.

Keywords: Echo-localization; Sports rehabilitation; Visually impaired people.

Fig. 1

Different snap-shots of the CNFST football soccer practice. It is mandatory for all athletes to wear blindfolds to ensure a fear match

Fig. 2

A caller before shooting. He or she hits the four corners of the goal and then locates behind the goalkeeper, to indicate him where to move to catch the ball

Fig. 3

Different drawings of the designed electronic goal. Each column is one module and it is assembled in a unique way with respect to the others

Fig. 4

Picture of the electronic goal developed in this work mounted on an iron goal

Fig. 5

Schematic drawing of one module of four cells from the electronic goal

Fig. 6

Connection among all modules in the electronic goal

Fig. 7

General layout of the training system

Fig. 8

First shooting with the electronic goal

Fig. 9

Pre-questionnaire: quantification of the need of a caller during training

Fig. 10

Pre-questionnaire: quantification of the dependence on the caller

Fig. 11

Post-questionnaire: quantification of the replacement of the caller during shooting practices

Fig. 12

Post-questionnaire: quantification of the self-sufficiency during training

Fig. 13

Post-questionnaire: quantification of the comfortability using the electronic goal

Fig. 14

Post-questionnaire: quantification of the efficiency of the electronic goal

Fig. 15

Post-questionnaire: the most important training mode of the electronic goal