Table 2.

Quality appraisal of included studies

	Bennett et al. (2012) [50]	Bring et al. (2017) [51]a	Buist et al. (2010) [10]	Davis et al. (2003) [52]	Davis and Mullineaux (2016) [24]	Desai and Gruber (2021) [59]	Hamill et al. (2007) [58]	Hein et al. (2014) [14]	Hendricks and Phillips (2013) [19]a	Hesar et al. (2009) [22]	Hespanhol et al. (2016) [20]	Jungmalm et al. (2020) [60]	Leetun et al. (2004) [15]a	Lun et al. (2004) [4]	Messier et al. (2018) [16]
Are the eligibility criteria appropriate for the aims of the study? e.g. were participants free from injury at baseline?	✓	✓	✓	?	✓	✓	✓	✓	✓	?	✓	✓	✓	✓	✓
Are the baseline assessment methods adequately described?	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Have the reliability and validity of baseline assessment methods been established?	✓	✓	*	✓	✓	✓	✓	*	*	✓	*	*	✓	*	*
Was the injury reporting method adequately described?	✓	✓	✓	X	X	X	X	✓	✓	X	Y	X	✓	✓	✓
For specific injury diagnoses, was there a suitably qualified assessor?c	X	n/a	n/a	?	n/a	n/a	?	?	n/a	✓	n/a	n/a	n/a	n/a	n/a
For specific injury diagnoses, was the assessor blinded to baseline results?c	X	n/a	n/a	?	n/a	n/a	?	?	n/a	?	n/a	n/a	n/a	n/a	n/a
For specific injury diagnoses, were all injuries diagnosed in the same manner?c	X	n/a	n/a	?	n/a	n/a	?	?	n/a	?	n/a	n/a	n/a	n/a	n/a
Did the authors state how they dealt with multiple injuries? e.g. only analysed first injuryd	X	X	n/a	X	n/a	n/a	X	X	n/a	n/a	n/a	n/a	n/a	n/a	n/a
Were important confounders (e.g. training load) accounted for?	X	X	✓	X	✓	?	✓	✓	X	✓	X	X	✓	✓	✓
Is it likely that attrition rates and/or reasons affected the results of the study?	?	✓	n/a	n/a	?	X	n/a	X	?	n/a	n/a	?	✓	X	✓

	Napier et al. (2018) [25]	Noehren et al. (2007) [26]	Noehren et al. (2013) [27]	Peterson et al. (2020) [53]b	Shen et al. (2019) [28]	Stafanyshyn et al. (2006) [29]	Hotta et al. (2015) [54]	Thijs et al. (2008) [55]	Thijs et al. (2011) [17]	Torp et al. (2018) [17]	Van Der Worp et al. (2016) [35]	Van Ginckel et al. (2008) [23]	Wen et al. (1998) [21]	Winter et al. (2019) [61]	Zifchock (2007) [57]
Are the eligibility criteria appropriate for the aims of the study? e.g. were participants free from injury at baseline?	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	?	✓	✓	✓	?
Are the baseline assessment methods adequately described?	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓	✓
Have the reliability and validity of baseline assessment methods been established?	✓	✓	✓	*	✓	✓	✓	✓	✓	*	✓	✓	?	?	*
Was the injury reporting method adequately described?	✓	X	X	✓	X	✓	X	X	X	✓	✓	✓	✓	X	X
For specific injury diagnoses, was there a suitably qualified assessor?c	n/a	✓	✓	n/a	?	✓	n/a	✓	✓	✓	n/a	?	n/a	n/a	?
For specific injury diagnoses, was the assessor blinded to baseline results?c	n/a	?	?	n/a	?	?	n/a	?	✓	✓	n/a	✓	n/a	n/a	?
For specific injury diagnoses, were all injuries diagnosed in the same manner?c	n/a	✓	✓	n/a	✓	✓	n/a	✓	✓	✓	n/a	✓	n/a	n/a	?
Did the authors state how they dealt with multiple injuries? e.g. only analysed first injuryd	n/a	X	X	✓	X	X	n/a	X	X	n/a	n/a	n/a	n/a	n/a	n/a
Were important confounders (e.g. training load) accounted for?	✓	✓	✓	n/a	✓	✓	✓	✓	✓	✓	✓	✓	✓	?	X
Is it likely that attrition rates and/or reasons affected the results of the study?	✓	n/a	n/a	n/a	?	n/a	X	✓	✓	✓	?	✓	X	X	X

✓ = low risk; X = high risk; ? = can’t tell; *some but not all measures were known by the reviewers to be reliable

^aData for eligible participants provided and re-analysed in this review

^bSome items incomplete as research is ongoing; additional information for some items provided by contact author

^cn/a applied if the outcome was injured vs. not-injured (risk classification only applied to studies investigating risk factors for specific diagnoses)

^dOnly applied to studies interested in a specific injury diagnosis (n/a for studies comparing RRI vs. no RRI)