The dorbarre warrior 3 - floor taps is a great leg exercise to strengthen your legs, core, and all the muscles to help increase stability. This exercise improves hip mobility and increases balance and stability. Learn more about properly executing this exercise with the video above.
Regression
Make this exercise easier by not bringing back foot up as high, or not going all of the way to tap the ground.
Progression
Make this movement more challenging by ensuring that you tap the ground, or bring your back leg up higher.