Table 2.

Demographic characteristics of the studies.

Author, publication date and country	Number of patients (total = 127)	Mean age, yr	Sex	Mean body mass index, kg/m2	Quantification of pain (pre-stimuli) and duration	Grade of knee osteoarthritis (Kellgren–Lawrence scale) and laterality of the analyzed knees
Quante et al (2008), Neustadt, Holstein Germany[42]	Total = 12OA = 12C = 0	OA = 61.4 ± 10.5	M = 3F = 9	Mean weight 83.4 ± 12.4 kgMean height 167.2 ± 9.0 cmMean BMI = 29.83	5.83 ± 0.94>6 months	IVUnilateral knee osteoarthritis
da Graça-Tarragó M et al (2016), Porto Alegre, Brazil[33]	Total = 31OA = 21C = 10	OA = 64.50 (SD = 7.72)C = 34.10 (SD = 11.64)	M = 0F = 31	OA = 27.53(SD = 5.11)C = NA	WOMACc 57.92 (SD = 13.25)>6 months	III–IVN/A (not reported knee osteoarthritis laterality)
Kittelson et al (2014), Colorado, USA, Colorado, USA[44]	Total = 37OA = 17C = 20	OA = 63.9 ± 1.8C = 58.3 ± 2.5	M = 18 (C = 10; OA = 8)F = 19 (C = 10; OA = 9)	OA = 28.3 ± 1.0 C = 25.0 ± 2.5	-	N/A (not reported knee osteoarthritis laterality)
Preece et al (2016), Manchester UK[43]	Total = 21OA = 21C = 0	OA = 62C = 61	M = 10F = 11	OA = 29 (SD = 4)C = 27 (SD = 4)	WOMACs = 9.6WOMACc = 45	Varying degrees OA (II–IV)Unilateral and bilateral OA
da Graça-Tarragó et al (2016), Porto Alegre, Brazil[45]	Total = 12OA = 13C = 13	OA = 62.15 (SD = 7.44)C = 66.85 (SD = 7.53)	M = 0F = 26	OA = 29.16 (SD = 6.65)C = 27.47 (SD = 4.20)	VAS (last 24 h)OA = 6.85 (SD = 0.38)C = 6.77 (SD = 0.43)WOMACOA = 54.92 (SD = 18.05)C = 52.46 (SD = 11.56)>6 months	III–IVN/A (not reported knee osteoarthritis laterality)