Tabriz University of Medical Sciences Medical Journal of Tabriz University of Medical Sciences 2783-2031 42 4 2020 10 28 The effect of long-term use of lumbar brace on the electromyography frequency spectrum of trunk and lower limbs in low back pain older adults with pronated feet during walking 394 401 10.34172/mj.2020.060 EN AmirAli Jafarnezhadgero https://orcid.org/0000-0002-2739-4340 Farshad Ghorbanloo https://orcid.org/0000-0002-1118-332X Ghader Ghane Journal Article 10.34172/mj.2020.060 2019 02 20 Background: Low back pain occurs between the lumbar vertebrae and the sacral bone and is affected by factors that often occur when trying to perform a particular operation or during a collision. The purpose of this study was to investigate the effects of long-term wearing of lumbar brace on the electromyography frequency spectrum of trunk and lower limbs in low back pain older adults with pronated feet during walking. Methods: This research was of a semi-experimental type. Fifteen patients with low back pain and pronated feet were selected as an experimental group (age: 68.3 ± 2.7 years) and Fifteen patients with low back pain and pronated feet were selected as a control group (age: 69.0 ± 3.9 years).The lumbar brace used in this research was Sacro Lumbar Support, BB-OPPO 2065 model, Taiwans. The electrical activity of the lower limb and trunk muscles were recorded by the electromyography system during walking in both pre and post-test. All statistical analysis was done on SPSS software by two way ANOVA analyses test at significant level of 0.05. Results: The findings in the experimental group demonstrated that the frequency content of the gastrocnemius medialis muscle during post-test was significantly lower than that during the pre-test (P=0.002). Also, two external oblique (P=0.007) and rectus abdominus (P<0.001) muscles showed a significant increase in their frequency content during post-test than that in the test pre-test. Conclusion: Results demonstrated that using of lumbar brace can increase abdominal muscle activity in patients with low back pain and pronated feet.