The Effect of Neuromuscular Training on the Frequency Spectrum of Lower Limb Muscles in Individuals with Foot Pronation Movement Disorder Syndrome Accompanied by Low Back Pain During Running

Abstract

Background: Chronic low back pain accompanied by foot pronation is often associated with inefficient neuromuscular patterns during running. This trial aimed to investigate the effects of eight weeks of Dynamic Neuromuscular Stabilization exercises on the frequency spectrum indices of selected lower limb muscles during running. Methods: 28 men with chronic low back pain (aged 22–25 years) were randomly assigned to an exercise group (n=14) or a control group (n=14). The exercise group performed an eight-week DNS training program, three sessions per week. Surface electromyography was used to record muscle electrical activity, and frequency spectrum indices were analyzed during the loading response, mid-stance, and push-off phases of running. Findings: A significant effect of time was observed in the loading response phase for the vastus lateralis, vastus medialis, rectus femoris, adductor, semitendinosus, and gluteus medius muscles (p<0.05). In the mid-stance phase, the frequency of the vastus medialis increased (p=0.004), and in the push-off phase, the frequency of the vastus lateralis increased (p=0.020). A significant time*group interaction was reported for the hamstring and vastus medialis muscles (p<0.05), with post-test results showing higher frequency values in the control group compared to the experimental group. Conclusion: After an eight-week period, significant time-dependent changes were observed in the frequency spectrum indices of several key muscles, especially the latissimus dorsi (mid-stance) and latissimus dorsi (push-off). Also, the between-group difference in the push-off phase favored the control group, indicating the variability of muscle frequency spectrum indices during running. © 2026, Isfahan University of Medical Sciences(IUMS). All rights reserved.