Efficacy of a trunk orthosis with joints providing resistive force on low back load during level walking in elderly persons

Junji Katsuhira,1,2 Ko Matsudaira,2 Hiroyuki Oka,2 Shinno Iijima,3 Akihiro Ito,3 Tadashi Yasui,4 Arito Yozu5 1Faculty of Medical Technology, Department of Prosthetics and Orthotics and Assistive Technology, Niigata University of Health and Welfare, Niigata, 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, 3International University of Health and Welfare Hospital, Tochigi, 4Kawamura-Gishi Company, Ltd., Osaka, 5Department of Rehabilitation Medicine, The University of Tokyo Hospital, Tokyo, Japan Purpose: The effects of lumbosacral and spinal orthoses on low back pain and gait are not exactly clear. We previously developed a trunk orthosis with joints providing resistive force on low back load to decrease such load, and confirmed its positive effects during level walking in healthy young adults. Therefore, we aimed to determine the efficacy of this trunk orthosis during level walking in healthy elderly subjects.Methods: Fifteen community-dwelling elderly subjects performed level walking at a self-selected speed without an orthosis, with our orthosis, and with a lumbosacral orthosis. Kinematic and kinetic data were recorded using a three-dimensional motion analysis system, and erector spinae activity was recorded by electromyography.Results: When comparing the three conditions, our orthosis showed the following effects: it decreased the peak extension moment, increased the peak flexion moment, decreased the lateral bending angle, increased the peak thoracic extension angle, and had significantly lower erector spinae activity and significantly larger peak pelvic forward tilt angles.Conclusion: Our orthosis with joints providing resistive force decreased low back load and modified trunk and pelvis alignments during level walking in healthy elderly people. Keywords: biomechanics, orthosis, gait, low back pain, joint moment, motion analysi