“…Eleven articles were conducted with professional players [1, 27, 33, 36-39, 41, 43-45], ten with amateur players [26, 28-32, 34, 42, 46-49], two with semi-professional players [40,42], and not enough information about the level of competition was available in one study [35]. The articles were designed as cohort studies in 18 cases (75%) [1,28,30,32,34,35,[37][38][39][42][43][44][45][46][47][48], case series in three (13%) [27,31,33], case-controls in two (8%) [26,40], and a randomized control trial (4%) [41]. Studies were conducted in the United Kingdom (n=9) [1, 26, 29, 36, 38-40, 42, 43], Australia (n=4) [37,41,44,45], New Zealand (n=3) [28,30,33], Ireland (n=3) [27,32,48], USA (n=2) [31,46], Morocco (n=1)[47], Japan (n=1) [34], and South Africa (n=1) [35] (Table 1).…”