Changes in Muscular Activity in Different Stable and Unstable Conditions on Aquatic Platforms

SIMPLE SUMMARY: Use of aquatic platforms in swimming pools is growing through their utilisation by individuals and group classes as a tool for promoting instability through water turbulence. Little is known about variations in muscle recruitment due to the introduction of instability, and the differences between types of exercise performed in a land (stable) environment and then performed on an aquatic platform (unstable). This study attempted to understand the changes in muscular activity of the erector spinae, biceps femoris, rectus femoris, external oblique, and rectus abdominis during the squat and plank in stable and unstable environments. For this purpose, participants performed squat and plank exercises in a stable environment (on land) and an unstable environment (on an aquatic platform) for 10 s with 40 s of rest. The results provide excellent evidence of muscular recruitment during squat and plank exercises, suggesting that exercises in unstable conditions on an aquatic platform could be a training alternative since water turbulence causes a slight increase in muscle activation. ABSTRACT: The present study aimed to analyse and compare the muscle activity of twelve participants (seven men and five women) (age 20.1 ± 0.9 years; height 170.5 ± 10 cm; body mass: 64.86 ± 8.3 kg) in two exercises, each with two variants: squat (dynamic and static) and plank (hands and elbows) in a stable environment on land and an unstable environment on an aquatic platform. The erector spinae, biceps femoris, rectus femoris, external oblique, and rectus abdominis muscles were evaluated using surface electromyography. The dynamic squat increases the recruitment of the biceps femoris and external oblique, while the static squat demands greater activation of the rectus femoris. The elbow plank exercise increases the recruitment of erector spinae muscles, and the hand plank exercise increases the recruitment of the erector spinae and external oblique. In conclusion, performing exercises in unstable conditions on an aquatic platform slightly increases muscle recruitment.