ThisissueofJournalofSportandHealthSciencecontainsapoint-counterpointdiscussionofhamstringinjuriesinsprintrunningbythegroupsofDrs.LiuandYu.~(1–4)Theyproposedifferentmechanismsofmuscleinjuriesingeneral,andhamstringinjuriesinsprintrunningspecifically.Yuetal.2,4presentevidencesuggestingthathamstringinjuriesareprimarilycausedbyexcessivemusclestrainduringeccentriccontraction.Inmaximaleffortsprintrunning,excessivemusclestrains