Rey et al. (2016) from the University of Vigo have recently published an article in which they have analyzed the impact of high and low flexibility levels of hamstring and quadriceps muscles on physical fitness and neuromuscular properties in professional soccer players. 62 male professional soccer players participated in this study, in which several tests including TMG have been performed. The results of the study support the rationale that baseline stiffness is likely to influence athletic performance rather than the flexibility level of soccer players. You can find the complete article here.