Fig. 4 

Number of the studies included in the review for each EXO (a) and number of studies addressing each domain (b). Ekso device: green columns; ReWalk device: blue columns; Indego device: red columns; HAL device: black columns; Rex device: orange columns. [Card./Met.: Cardiorespiratory and Metabolic responses; QoL: Quality of Life; HRI: Human Robot Interaction; Bowel_f: Bowel functionality; ADL: Activities of Daily Living; Neuroph.: Neurophysiology; Sensory_f: Sensory function; Bladder_f: Bladder functionality; Body/Bone: Body composition and bone density]