The single most important exercise you are NOT doing!
The most important lower body exercise you AREN’T doing!
Following Gray Cook’s joint by joint approach, one knows that the lumbar spine is supposed to be a stable and the hips are supposed to be mobile.
Performing a single legged deadlift (SLDL) helps this!
When trying the exercise, use a mirror and take note of what happens to your pelvis. It often turns upwards having the sacrum facing the weight bearing limb. This frequently involves one side being worse than the other.
Stand tall belly lightly drawn in
Begin by bowing forward and having one leg stick back behind you
Try ending up in an “airplane” position with flat back (that you can balance a glass of water on your lower back and return to starting position)
To remedy any stability issues, assume the bent over “see-saw” position, and physically try and correct the problem by dropping the elevated/hiked hip and make it face the floor so that your lower back or sacrum ends up flat (as if to hold a glass of water on it without spilling). You will surely feel crooked (but the mirror will show that you are in a proper position) and you will feel a noticeable stretch in the hamstrings of the weight bearing leg…PERFECT!
Doing this exercise for a set of 10-12 reps 1-2x per day will eventually help you to correct pelvic instabilities. You will be able to help rectify core imbalances in a weight bearing position and actively stretch your hamstrings as well! When, and ONLY when, you have mastered the movement should you load the exercise with weights in your hands.
The SLDL is a KEY exercise, especially with runners or athletes that rely on one leg landing who experience pelvic imbalances as well as underuse of their (should be) powerful hip extensors.