Purpose The purpose of this study was to investigate the effect of visual information and ground stability on muscle activation of upper extremity muscles during doing pushup. Methods Participants were adult male college students (n = 19) who could do pushup normally. The subjects first measured the MVIC (Maximal Voluntary Isometric Contraction) after attaching the electrodes to the upper Trapezius, lower Trapezius, Serratus anterior, and Pectoralis major. After that, muscle activation was measured during doing pushup. The environment for pushup was divided into four conditions according to visual information and the stability of the ground. Results As a result, the rest of the muscles except lower Trapezius showed differences in muscle activation according to the stability of the ground in an environment that provided or blocked visual information. However, compared to upper Trapezius and Pectoralis major showing higher muscle activation on unstable ground, Serratus anterior showed lower muscle activation on unstable ground. Conclusion The stability of the ground affects the difficulty of pushup before visual information. Afterwards, the difficulty level on the neck and upper shoulder can be adjusted according to visual information.