Begin in the all-fours position with your knees about hip-width apart and your hands straight out under your shoulders.
You may find it helpful to position your hands a bit wider than shoulder-width apart for more stability.
Brace your core and keep your spine in a straight neutral position throughout the exercise.
Push one foot backwards and upwards, keeping your knee bent.
Your knee angle should not change much, instead focus on using your glutes to lift your foot directly toward the ceiling.
This is not about how high you can lift your foot, but rather how hard you can squeeze your glutes while keeping a flat back and neutral spine.
Return to the starting position and repeat with your other leg.