Background: The present study was conducted with 30 adult males in order to examine the muscle activity of the trunk and the lower extremities at diverse initial bending angles of the hip joint during bridge exercise on a stable surfaces and on an unstable surface that is widely performed for stabilization. Methods: The initial angles of the hip joint used were $0^{circ}$, $45^{circ}$ and $90^{circ}$ and the subjects were divided into a matt experimental group and a balance training group. Results: In maximum values of muscle activity at different exercise methods and angles, the matt experimental group showed statistically significant differences in the muscle activity values of the rectus abdominis muscle, the erector spinae muscle, the rectus femoris muscle and the peroneus muscles between different angles while the balance training group showed significant differences only in the muscle activity values of the erector spinae muscle between different initial angles of the hip joint. The matt experimental group showed significant differences in muscle activity between initial angles $0^{circ}$ and $90^{circ}$, between $45^{circ}$ and $90^{circ}$ in the rectus abdominis muscle, between $0^{circ}$ and $90^{circ}$ in the erector spinae muscle, between $45^{circ}$ and $90^{circ}$ in the rectus femoris muscle and between $0^{circ}$ and $90^{circ}$ in the peroneus muscles while the balance training group showed significant differences between $0^{circ}$ and $90^{circ}$ in the erector spinae muscle. Conclusions: Therefore, it is thought that bridge exercises should be applied to patients using diverse methods.