Developing chair-based exercises for lumbar stabilization: Analysis via electromyography and ultrasound imaging

BackgroundLumbar stabilization exercises (LSEs) are commonly used to improve spinal stability; however, few studies have evaluated LSEs performed in the sitting position.ObjectiveTo investigate the characteristics of newly developed chair-based LSEs based on muscle activity.MethodsThis prospective, single-group study included 23 healthy males. Trunk muscle activity during exercise was evaluated using surface electromyography and ultrasonography to compare two newly developed chair-based lumbar stabilization exercises with conventional LSEs. The Lateral Abdominal Expansion (LAE) and Hip Flexion with Arm Resistance (HFAR) exercises, both involving isometric contractions, were specifically developed for this purpose.ResultsThe two chair-based exercises showed a greater preferential activation ratio of the transversus abdominis than did the prone and side bridges. Furthermore, transversus abdominis/internal oblique activity was greater in LAE than in all conventional LSEs and in HFAR than in the prone and side bridges. Conversely, multifidus activation was lower during LAE and HFAR than during the bridge and bird-dog but remained greater than that observed in the draw-in and prone bridge.ConclusionThe LAE and HFAR may be promising for the preferential activation of the transversus abdominis and multifidus.