Table I.

Baseline characteristics of the studies included.

A, ESWT vs. placebo
First author, year	OA joints included	Size of intervention group (ESWT), n	Size of control group (placebo), n	Outcomes	Follow-up	(Refs.)
Chen et al, 2014	Bilateral knees	30	30	1. ROM	After 8 weeks (physical and placebo)	(18)
				2. VAS (after walking or standing 5 min)	After 6 weeks (ESWT)
				3. Li
Cho et al, 2016	Bilateral knees or unilateral knees	9	9		After 1 week	(19)
Elerian et al, 2016	Bilateral knees	20	20	VAS	WOMAC	(20)
				ROM	After 8 weeks
Imamura et al, 2017	Bilateral knees	52	53	VAS	After 12 weeks	(15)
				WOMAC
Zhao et al, 2013	Unilateral OA or more painful side	30	31	1. VAS	After 4 weeks and 12 weeks	(21)
				2. LI
				3. WOMAC
B, ESWT vs. physical therapy
First author, year	OA joints included	Size of intervention group (ESWT), n	Size of control group (placebo), n	Outcomes	Follow-up	(Refs.)
Chen et al, 2014	Bilateral knees	30	30	1. ROM	After 8 weeks (physical and placebo)	(18)
				2. VAS	After 6 weeks (ESWT)
				3. LI
Lee et al, 2017	Bilateral knees	10	10	1. VAS	After 4 weeks	(22)
				2. WOMAC
Lizis et al, 2017	Unilateral knee	20	20	ROM	After 5 weeks	(23)
				WOMAC

OA, osteoarthritis; ESWT, extracorporeal shockwave therapy; ROM, range of motion; VAS, visual analogue scale; LI, Lequesne index; WOMAC, Western Ontario and McMaster Universities osteoarthritis index.