Letter to the Editor regarding «Sprint mechanics return to competition follow-up after hamstring injury on a professional soccer player: A case study with an inertial sensor unit based methodological approach» by I. Setuain, P. Lecumberri, and M. Izquierdo

Beyond the fact that this player doubles his horizontal force capability over a soccer season, which includes a mid-season hamstring injury, these F0 values are: (i) approximately double and triple, respectively, the values reported by the same authors in recreational runners of similar average body-mass (∼5.5 N kg−1) (Setuain et al., 2017); and (ii) similar (pre-season) to double (end-of-season) the values expressed by elite sprinters (best 100-m time under 10 s, F0 = 9.95 N.kg−1), measured using in-ground force plates by Rabita et al. Since Setuain et al. did not follow the exact methodology described in the original method of Samozino et al. Should research help solving this major health issue in sports and the associated economic burden on athletes and sport institutions, this must, in our opinion, be based on valid, reliable and transparent methodologies and experimental data.Conflict of interest statement The authors declare that they have no conflict of interest.