The systematic review erroneously reported that the study by Roffers et al. (Ref. 27) was conducted in the US while in fact it was conducted in El Salvador. Roffers et al. also would like to add that their subjects were classified into clinically relevant classes (Normotensive, Prehypertensive, Stage I hypertension, and Stage II hypertension), and that about 72% of their subjects were hypertensive.
[Hong Kong Physiotherapy Journal, Vol. 40, No. 2 (2020) 75–87, https://doi.org/10.1142/S1013702520500122]