Comparison of the electromyographic activity of core muscles during ventral plank exercise until exhaustion using different unstable equipment

This study aimed to analyze and compare the electromyographic activity, root mean square, and median frequency, of the rectus abdominis, external abdominal oblique, and erector spinae muscles during the ventral plank exercise until exhaustion in five distinct conditions: 1) normal stability (VP-GR), 2) instability with bosu (VP-BS), 3) gym ball instability (VP-GB), 4) instability with peanut ball (VP-PB), and 5) instability with TRX® (VP-TX).

Overall, 15 physically active men (23 ± 2.00 years, body mass 74.13 ± 4.05 kg, height 176.06 ± 4.22 cm, fat percentage 12.06 ± 3.04%) were enrolled. The electromyographic signal was analyzed in the temporal (root mean square—RMS) and spectral domains (median frequency) in different stages: beginning (stage A: 5 to 10 s), middle (stage B: 50% signal), and end (stage C: 100% signal). The Shapiro–Wilk test was used to assess normality, and the two-way analysis of variance test was used to verify differences, with a significance level of p < 0.05.

The main results indicated a difference between the instability equipment, whose higher RMS and lower Fmed values were found for the VP-TX exercise.

The VP-GR exercise seems to be the best choice for the initial stages, followed by the instability equipment (1- Bosu, 2- Gym ball, and 3- Peanut ball, specifically in that order) and lastly, the VP-TX exercise until exhaustion.