Effects of Wearable Lumbar Support Exoskeleton on Motion of Torso and Dynamic Plantar Pressure in Single-Shoulder Load

Work-related musculoskeletal disorders are a major health issue, but there is little research to show whether active lumbar exoskeletons are suitable for single-shoulder load. The purpose of this study was to identify the effect of wearable lumbar support exoskeleton with single-shoulder load on movement of the lumbar and thoracic spine and plantar pressure. The experiment was conducted considering ten healthy male young adults. Data about three-dimensional motion angles of the lumbar and thoracic spine, as well as plantar pressure, were collected in the control condition (0% of body weight: 0% BW), experimental condition A (single-shoulder load: 5% BW and 10% BW), and experimental condition B (single-shoulder load and left lateral traction: 5% BW-T and 10% BW-T). The two-way repeated measures analysis of variance (ANOVA) was conducted with device and weight as within subject factors. The level of statistical significance was set at p<0.05. In experimental condition A, significant difference observed in the lumbar and thoracic flexion angle compared to 0% BW (all p<0.05). the plantar pressure information was affected by the single-shoulder load especially about plantar pressure. In experimental condition B, there were no significant differences on the all values of lumbar and thoracic angles other than the ROM value of thoracic rotation angle in 5% BW-T and 10% BW-T (p = 0.0082 and p = 0.0056). Furthermore, the COP of the subject was symmetrical in experimental condition B, the peak force increased compared to 0% BW but less than the single-shoulder load. The WLSE provided a possibility for protecting and preventing the human lumbar and thorax in single-shoulder load.