The posterior chain is a group of muscles that run along the back of the body, including the glutes, hamstrings, traps and rear delts. The posterior chain includes the largest most powerful muscles of our body, but is often neglected. This is down to a multitude of reasons. Many of us work desk jobs, which can cause poor posture and 'lazy' glutes, which in turn lead to quad dominance. It is also common for people to overtrain anterior muscles such as the pecs and abs, compared the the posterior, resulting in further imbalances.
Having a dedicated posterior chain (usually back and hamstring focused) day can be beneficial to allow those muscles to catch up. Developing the posterior chain will protect the spine and carry over to increased strength in other exercises.
Back and Hams
Exercise 1: Deadlift
An amazing compound movement which hits the entire posterior chain. You can work in a lower rep range for these.
Exercise 2: Single Arm Low Row
Drive the elbow right back. Work up to a heavy weight that you can still control (not throwing it up). Can be substituted for a DB row if your gym does not have this machine.
Exercise 3: Good Mornings
Good mornings are a very underrated exercise that you don't often see in commercial gyms. Push the hips back and shift weight slightly into the heels to perform. You should be feeling these in the hamstrings, not so much the back (similar movement to the stiff legged deadlift, but with the weight loaded differently).
Exercise 4: Row Machine
Use a basic pin row machine and feel the squeeze in the mid back.
Exercise 5: Lying Hamstring Curl Machine
The lying hamstring curl are an excellent exercise that is often executed poorly. Focus on driving your hips into the pad so that they are not moving during the set. Feel the hamstring extend in the lengthened position. It can be beneficial from time to time to drop the weight right down to establish a mind-muscle connection and avoid using momentum to get more reps!
Exercise 6: Rope Face Pulls
Pull the rope apart, not just back, to hit the rear delts and not the traps. You don't want to go too heavy with these. Focus on form.