Effects of a trunk exoskeleton on pain during functional activities: a crossover randomized clinical trial.

Purpose Chronic lower back pain is a multifactorial health problem that can involve the intervertebral discs. The objective of the present clinical trial was to describe the effect of a trunk exoskeleton on the level of pain experienced during a standardized activity track. Materials and Methods Thirty-one patients with chronic lower back pain agreed to wear the device daily and perform a standardized activity track as part of a hospital-based multidisciplinary rehabilitation programme. The participants were randomized to use the device on day 4 but not on day 5, or vice versa. Blinding was not applicable because the patient and investigators could not be blinded to the intervention ( wearing or not wearing the device) Results The mean ± standard deviation (SD) pain visual analogue scale (VAS) score in the standardized activity track was 4.6 ± 1.6 mm lower with the device (albeit not significantly) than without the device. The reduction in the pain VAS score after wearing the device for an hour ranged from 12 ± 21 to 15±21 mm. The percentage of pain-free patients (i.e. with a pain VAS score ≤ 30 mm) was similar in the two groups. Seventeen (54.8%) of the 31 participants showed a decrease in the pain level >20 mm when wearing the device; this proportion was significant lower when the device was not worn. Conclusion Although the study did not evidence a significance difference in the primary endpoint, use of the device was associated with a higher proportion of patients experiencing a reduction in pain levels.