“…Two articles differed from these categories: one study analyzed the effectiveness of an alternative therapy (lavender ointment) [49] and the other one, a thermal agent (paraffin wax) [50]. Twelve studies had a control group [22,25,27,28,33,[41][42][43][44][45][46]; nine studies a placebo group [21,29,[37][38][39][40]42,48,49]; and thirteen studies an alternative treatment [23,24,26,27,30,32,[34][35][36][37]39,47,48]. There were six articles having three or more groups [27,32,37,39,42,48].…”