Table 1.

Case definition of sprains [25]

Grade	Definition
I	Sprain occurs when ligamentous fibers are stretched but remain structurally intact.
II	Sprain occurs when ligamentous fibers become partially torn. Physical stress reveals increased laxity with a definite end point.
IIIa	Sprain occurs when a ligament is completely torn, leading to gross instability.

^aGrade III sprains are excluded from this review; grade I-III ankle sprains and strains were considered if a grade specific analysis was conducted or if a trial included the same distribution of grade III injuries between intervention groups