good mornings

The Good Morning is an exceptional exercise for stretching the hamstrings and in some cases the ankles. It also helps for developing the hamstrings for athletic movements.
In other words, if your deadlift is 300lbs and you can back squat 255lbs or more, it’s time to work on building up your deadlift a bit.
To build a balanced, strong, injury-proof physique you need to do some unilateral training.