EFFECTS OF COMMERCIALLY-AVAILABLE TENNIS SHOES ON MOTOR PERFORMANCE

Abstract

Introduction: Different studies (Robinson et al., 1986; Valiant and Himmelsbach, 1996; Brizuela et al., 1997) have shown that motor performance is affected by important differences in the design of footwear. However, such studies were made with non-commercial prototypes. The objective of this study was to determine whether motor performance is affected by tennis shoes available in the market. Methods: A sample of shoes was selected, comprising the 10 best-selling tennis available shoes in Valencia. The subjects were 6 tennis players who met certain requirements. Each subject tested each type of footwear two times on a circuit which reproduced the most common movements in tennis. The time subjects needed to complete the circuit was recorded by means of two photocell sets, placed at the start and finish of the course, connected to a chronometer with a precision of a thousandth of a second. The tennis players also scored the functional adequacy of the shoes according to their subjective perception, without knowing the time taken to complete the circuit. This subjective variable was analyzed by means of a Likert type score of 5 levels. An ANOVA was made with the time taken to complete the circuit, with each subject and each shoe as factors, setting the significance level at 0.05 and making a post hoc LSD analysis. A Kruskal-Wallis test (non-parametric ANOVA) was made with the subjective variable. With both results, a non-parametric correlation analysis was done (Spearman). Results: The results showed significant differences (p<0.001) in the mean times registered for the 10 models, being the extreme differences of 5%. In the same way, the results obtained for the subjective evaluation showed significant differences among models. Both results showed a significant correlation (r=0.6445, p=0.007). Conclusions: From the results it can be concluded that small differences in footwear design have an influence on motor performance. The correlation found between the times needed to complete the circuit and the subjective evaluation also supports the use of subjective tests in the biomechanical study of footwear. References: Brizuela, G.; Llana, S.; Ferrandis, R.; García, A.(1997). The influence of basketball shoes with increased ankle support on shock attenuation and performance in running and jumping. Journal of Sports Sciences 15, 5, 505-515. Robinson, J. R.; Frederick, E. C.; Cooper, L. B. (1986). Systematic ankle stabilisation and the effect on performance. Med. and Sci. in Sports and Exer. 18, 6, 625- 628. Valiant, G.A., Himmelsbach, J.A. Performance tests to evaluate forefoot stability of basketball shoes. In Marshall, R.N., Wood, G.A., Elliot, B.C., Acland, T.R., McNair, P.J. (Eds), XIIth International Congress on Biomechanics, Perth, Australia.