Immediate Effect of Trunk Flexion And Extension Isometric Exercise Using An External Compression Device On Electromyography of The Hip Extensor And Trunk Range of Motion Of Healthy Subjects

Abstract

Background: Low back pain (LBP) is a very common symptom experienced by individuals across all age groups. Previous study established that using a device known as Active Therapeutic Movement version 2 (ATM®2) has been developed to improve pain and joint range of motion (ROM) in patients with LBP. However, no study has examined the physiological change in the muscle through ATM®2-based exercise thus far. This study aimed to determine the immediate effects of ATM®2 exercise on the contraction timing, back extension endurance, muscle fatigue, and trunk ROM of lumbar and lower limb muscles in healthy subjects.Methods: Thirty-six healthy subjects (mean age=23.16±2.3) volunteered to participate in this study. Subjects were instructed to perform ROM test using sit and reach test, back extensor endurance test using Biering-Sorensen test, erector spinae (ES), lumbar multifidus (LM) fatigue and onset time of Gluteus maximus (GM) in prone hip extension using electromyography before and after trunk flexion and extension isometric exercises.Results: The ROM in trunk flexion showed a significant increase by 7.9% after exercise compared to that before exercise (p<0.05). Relative GM contraction onset timing significantly decreased after exercise (p<0.05). The result of the Sorensen test after exercise showed a trend of increase in duration time. Muscle fatigue in the LM, however, showed a significant increase (p<0.05), whereas muscle fatigue in the ES was reduced without statistical significance.Conclusions: The results base on this study showed a significant increase in the trunk ROM after trunk flexion and extension isometric exercise using an external compression device, while the relative contraction onset timing in the GM significantly reduced. Furthermore, the muscle endurance test after exercise showed a trend of increase in the duration time with a decreasing trend in muscle fatigue in the ES. Exercise based on ATM®2 is an effective exercise protocol with an effect on biomechanics of healthy subjects. This exercise may be suitable in clinical practice for patients with LBP, for which long-term effects can be expected.