Physically fit young male university students (N = 30) performed five push-ups under stable conditions (on the floor) and using four unstable devices (wobble board, stability disc, fitness dome, and the TRX Suspension Trainer). The push-up speed was controlled using a metronome, and the testing order was randomized. The average amplitudes of the electromyographic (EMG) root mean square of the anterior deltoid (DELT), serratus anterior (SERRA), lumbar multifidus (LUMB), and rectus femoris (FEM) were recorded. The electromyographic signals were normalized to the maximum voluntary isometric contraction (MVIC).
No significant differences were found for the DELT [F(4,112) = 1.978; p = 0.130] among the conditions. However, statistically significant differences were found among the different conditions for the SERRA [F(4,60) = 17.649; p < 0.001], LUMB [F(4,76) = 12.334; p < 0.001], and FEM [F(4,104) = 24.676; p < 0.001] muscle activation. The suspended device was the only condition that elicited higher LUMB and FEM activation compared to the other conditions. Push-ups performed on the floor showed lower SERRA activation than those performed with all unstable devices.
Not all unstable devices enhance muscle activation compared to traditional push-ups.