2.6.2. Abdominal Muscle Activity
RA
CONTRACTION
Muscle activity was measured using surface EMG (Mini-wave Infinity Waterproof, Cometa Systems, Italy). The EMG signals were converted from analog to digital, and an EMG analysis software (Myoresearch XP Master ver. 1.07, Noraxon, Scottsdale, AZ, USA) was utilized, with the sampling rate set to 2000 Hz. The raw EMG data underwent full-wave rectification and were then quantified to an RMS of 150 ms. The data were filtered within a range of 20–450 Hz using a digital band-pass filter (Lancosh FIR). Ag/AgCl electrodes were used for the measurements. Before attaching the electrodes, to minimize skin resistance, any hair was removed, and the skin was exfoliated with sandpaper and cleaned with an alcohol swab. The specific attachment sites for each muscle are listed in EMG was performed on the RA, EO, and IO muscles. To determine the baseline values for these muscles, the participants were asked to lie down with their knees bent and to lift both feet approximately 8 cm off the ground for 3 s. The average effective value was then calculated [Abdominal muscle activity was measured using EMG during the intervention. The average EMG signals were derived from the muscle activity measured during the assigned exercises, excluding the first and last second of each set. The effective values of each muscle recorded during the exercise motion were compared with the contraction values of the standard posture for analysis.