Hamilton B. Hamstring muscle strain injuries: what can we learn from history? (Br J Sports Med 2012;46:900–3). The sentence ‘It is true that coach and trainer still attempt to exert their influence by calling men yellow at times who claim to have been injured, or try to bring undue influence on the athletic physician to permit an excellent player to return to competition before he should.¹⁸’ was a direct quote from reference 18, and should have been in italic and in quote marks.