Feasibility and tolerance of a robotic postural training to improve standing in a person with ambulatory spinal cord injury.

An ambulatory elder with SCI, AIS C, balance deficits, and right ankle-foot-orthosis participated. RobUST-intervention comprised six 90 min-sessions of postural tasks with pelvic assistance and trunk perturbations. We collected three baselines and two 1 week post-training assessments-after the first four sessions (PT1) and after the last two sessions (PT2). We measured Berg Balance Scale (BBS), four-stage balance test (4SBT)-including a 30 s-window with and without vision-standing workspace area, and reactive balance (measured as body weight%). Kinematics, center-of-pressure (COP), and electromyography (EMG) were analyzed to compute root-mean-square-COP (RMS-COP), the margin of stability (MoS), ankle range of motion, and integrated EMG (iEMG) normalized to baseline. The Borg Rating of Perceived Exertion (BRPE), and change in the Mean Arterial Pressure (MAP) and heart rate (HR) compared with baseline were collected to address training tolerance. A 2SD-bandwidth method was selected for data interpretation. The maximum BBS was achieved (1-point improvement). In the 4SBT, the participant completed 30 s (baseline = 20 s) with reduced balance variability during semi-tandem position without vision (RMS-COP baseline = 50.32 ± 2 SD = 19.64 mm; PT1 = 21.29 mm; PT2 = 19.34 mm). A trend toward increase was found in workspace area (baseline = 996 ± 359 cm; PT1 = 1539 cm; PT2 = 1138 cm). The participant tolerated higher perturbation intensities (baseline mean = 25%body weight, PT2 mean = 44% body weight), and on average improved his MoS (3 cm), ankle range of motion (4°), and gluteus medius activity (iEMG = 10). RobuST-intervention was moderate-sort of hard (BRPE = 3-4). A substantial reduction in MAP (9%) and HR (30%) were observed. In conclusion, RobUST-intervention might be effective in ambulatory SCI.