Horizontal Press
If push ups don't agree with you then the horizontal press using resistance bands is a great alternative. Adopt a split stance with a tall spine. Take a band / handle in each hand and step forwards till you feel some tension in the elastic. Brace your legs and torso to create a solid platform to push from. Smoothly push forward with both arms maintaining a strong posture throughout - don’t let the bands push you around. Pause when you reach the end of range of motion before slowly returning to the start position and repeating.