One of my favorite posterior chain exercises is the the Single Leg Romanian Deadlift (SLRDL). There are many ways to load the exercise: cable, barbell, one dumbbell. Here, I have my client using two kettlebells. She had done the single arm version for a couple weeks and I wanted to increase the load so we went to the two arm version. The way she is performing the exercise is just about perfect. Good hip hinge, good extension of the trail leg and a nice neutral spine throughout the set.