Sometimes one needs to access fine manipulation of the pelvic bowl.  Why? Options in movement that’s why!  Not enough of a reason?  Ok, what if knowing the difference between and being able to execute a pelvic roll vs. thrust could help with your posture?  Or reduce stress in your low back? Or help your hips function better and make weight bearing more efficient?  Or help you have better SEX?????  Ok, so now that we have your attention check it out.

When you perform a pelvic thrust properly one needs to engage the glutes.  This is easy to feel.  Lay on the floor with your knees bent and feet flat.  Now do a bridge pushing your pelvis straight towards the ceiling.  See?  Pelvic thrust; glutes engaged.  You can feel this while standing.  Stand with feet about hips width apart and with the spine in neutral (exerting as little effort as possible to hold yourself upright).  Now squeeze your butt.  When you engage your glutes you will automatically move your pelvis forward a bit.  A mini-thrust if you will.  This happens, because when we squeeze our glutes this moves the head of our femur bones toward the front of the hip socket.  Over excessive “squeezing” can lead to improper joint centration or in other words “propping” on the joints. This can cause stress on the ligaments at the front of the hip joint. For most of us, this effect on the femur head will result in a slight forward movement of the pelvis; thus the thrust.  Please Note: It is possible to thrust without a pelvic tilt upward. 

Check out this video from the awesome Dr. Evan Osar to see a demo of this hip joint centration.

Conversely, when one properly executes a pelvic roll you are minimally engaging the glutes (they are NOT the initiators) while the majority of muscle work is in the abdominals and spinal muscles.  So, let’s go back to laying down on the floor.  Same position, plant your feet with the knees bent.  Now, without lifting off the floor, tilt your entire pelvic bowl  towards your face. To do this, one must engage the abdominals, pelvic floor and allow the muscles of the spine, particularly the lumbar region, to relax and lengthen.  You’ve essentially performed part of cat/cow in another variation.  Now do this while standing.  You may find that you have difficulty trying to execute this movement as well standing as you did lying down.  Why?  Because, now that you are contending with gravity (legs are weight bearing) it may be:

A) More difficult for you to know where to move from.  You have to sense deeper than just standing on your legs to find the right places to do the roll.

B) The support you need from deep intrinsic muscles in between vertebrae may not be strong enough to provide it.  This lack of strength can also be the reason it’s difficult to engage the deep abdominal muscles and muscles of the pelvic floor.

This picture becomes relevant soon.  Keep reading!
This picture becomes relevant soon. Keep reading!

That being said, when one can execute a pelvic roll correctly the entire pelvic girdle moves while the hip socket maintaining an equal amount of space around the femur head (joint centration).  This movement takes refined awareness of sensing from where one is initiating movement, which muscles are being engaged and refined/consistent muscle control. The pelvic roll, particularly when tilting the pelvis back and up (“duckbutt”) puts a demand on deep postural muscles in the spine (Spine?! Confused?  Don’t be.  What’s part of the posterior area of the pelvic bowl?  The sacrum.  And what’s the sacrum the end of? The spine…oooooooh.) that may have slackened over time. Think of how the lower back gets tired when you’ve been sitting for a long time and how that affects the shape of the entire spine, like rounding the thoracic spine forward. Re-establishing a working relationship with these muscles can help restore postural integrity, which can alleviate stress anywhere in the back and neck, can help you establish better balance and can help you breathe better. Remember the previous post about breathing and the pelvic floor?

Bonus: If you were to add an upward pelvic roll to your pelvic thrust you might impress your partner…when dancing.  Yeah…dancing….