Differences in Cardiovascular Intensity Between Gait Training Approaches After Incomplete Spinal Cord Injury-A Randomized Controlled Trial.

BACKGROUND: Spinal cord injury (SCI) often leads to severe mobility impairments, necessitating intense rehabilitation to promote recovery and optimize outcomes. Overground robotic exoskeletons (ORE) are emerging gait training tools, but their capacity to elicit moderate-to-vigorous intensity (MVI) in subacute SCI is unclear. OBJECTIVES: To compare the intensity of usual care (UC) and ORE gait training in patients with subacute, motor incomplete SCI and examine the relationship between training intensity and walking function. METHODS: A single-blind randomized controlled trial was conducted at an inpatient rehabilitation hospital. Patients (n = 106) were age 51.5±18.5 years; 78.3% were male with severity of 17.9% AIS B, 28.3% AIS C, and 53.8% AIS D. Patients were randomized to UC or ORE gait training. Main outcomes were percentage of session time at MVI (>40% heart rate reserve [HRR]), rating of perceived exertion (RPE), step count, and change in Walking Index for Spinal Cord Injury (WISCI-II). RESULTS: UC and ORE groups spent a similar percentage of session time in MVI (17.6% vs. 19.5%, P = .398) and had comparable step count (387.1 vs. 461.8 steps, P = .625). However, RPE was higher in UC (5.6 ± 1.9) versus ORE (4.5 ± 1.8, P = .003). Both groups increased step count over time with ORE achieving more steps early and UC later. Step count was moderately correlated with WISCI-II improvement (r = 0.38-0.51, P < .001), while percentage of MVI demonstrated weak correlation (r = 0.23, P = .032). CONCLUSIONS: UC and ORE provide similar physiologic dose, though ORE may offer intense training with less perceived effort. Step count appears to be an indicator of training intensity that correlates to functional recovery.