Fig. 1

Devices used and protocol design. a Picture of ActiGraph wG3TX-BT; b picture of Metria-IH1; c The sensor locations used, ActiGraphs (red color) were placed on the right side upper arm, waist and ankle while the Metria-IH1 (grey color) was placed on the back side of left upper arm. The Cosmed K4B2 was body mounted with the rubberized facemask; d) the experimental design and the spectrum of activities

executed during the protocol. To execute the study protocol, participants performed a set of structured indoor activities in a controlled laboratory setting. (e) The spectrum of the performed activities was categorized into three levels, (i) sedentary activities: lying down on a treatment table, sitting and standing (with or without assistive device) for two minutes each, (ii) low intensity activity: walk 50 steps, and (iii) high intensity activities: a six-minute walking test (6MWT) and two minute of fast paced multi sit-to-stand activity. Sufficient rests and recovery were provided between all the performed activities. All the three devices, namely, the Actigrpah, Metria and Cosmed K4B2 continuously collected data during the entire protocol