RESUMO
Objective To explore any changes in surface electromyogram (sEMG) signals from the lumboabdominal muscles during exercise on stable and unstable surfaces. Methods sEMG signals from the lumbo-abdominal muscles of 33 healthy young persons [18 male and 12 female; average age (26.5 ± 4.3 ) years] were measured with the FlexComp Infiniti apparatus.Each subject performed 5 exercises on and off a Swiss ball:sit,bridge,bridge with both knees flexed,reverse bridge as well as press-up. Results ①In bridging there was a significant increase in the activation of the erector spinae during exercise on the ball compared with on the stable surface.②Bridging with both knees flexed gave a significant increase in activations of the erector spinae,the external obliques and the transverses abdominus/internal obliques during exercise on the unstable surface compared with the stable surface.③During reverse bridging there was a significant increase in activation of the erector spinae and rectus abdominus during exercise on the unstable surface compared with the stable surface.④During press-ups there was a significant increase in activation of the rectus abdominus,the external obliques and the transverses abdominus/internal obliques during exercise on the ball compared with the stable surface. Conclusion The unstable surface provides better training stimulus for the activation of the lumbo-abdominal muscles.
