Deep squat extension-rotation
Use this exercise as a warm up prior to movements requiring the squat pattern (back squat, front squat, olympic clean, etc.) to improve mobility and deep core activation.
Have the athlete take a shoulder width stance, then bend over at the hip with the arms out stretched. Once hamstring ROM has been exhausted, release the arms and bend over to grab the toes. Have the athlete use their arms to pull themselves down into a full squat. Keep the core engaged to maintain a neutral back, release one arm and rotate the torso up keeping the knees inline with the toes. The head and eyes should follow the hand. Replace the hand and repeat.
Athletes who lack the mobility to get into a deep squat without lumbar flexion can place dumbbells between the feet to hold onto.