Table 1. Characteristics of included studies.

Study	Design	Level of evidence	Region	No. of centers	Age, years (mean)	Sample size (No. of patients)
						Total	No orthosis	Rigid	Soft
Kato et al. 2019 (19)	RCT	I	Japan	71	75.5	284	–	141	143
Kim et al. 2014 (18)	RCT	I	South Korea	1	70.2	55	18	18	19
Pfeifer et al. 2011 (20)	RCT	I	Germany	1	71.6	108	36	36	36

RCT, randomized controlled trial.