Back, Core, Shoulders, Glutes
Begin in a high plank, with arms straight, wrists lined up under shoulders, legs at shoulder distance apart or slightly wider for better balance.
Keep your back completely flat, and engage your core to keep your lower back from dipping down.
Extend your right arm forward while lifting your left leg back. Hold for required amount of time and then bring your arm and leg back down.
Be sure to keep your active arm and leg parallel to the floor. Trying to raise them higher than parallel often results in the hips dipping downward, which puts stress on the lower back.
Progressions And Regressions