The Sacro-Iliac (SI) joint is in fact two joints – one on each side of your sacrum where it meets the back of your pelvis.

SI Joint pain presents it’s self locally on one or both sides of the sacrum/tailbone. SI Joint pain is the most common complaint during pregnancy, often flaring in the 3rd trimester. The pain can often radiate along the hip (Ilium) crests and low back.

Si JointSI Joint


  1. The SI joint is a very vulnerable and unstable joint even before pregnancy
  2. The hormone Relaxin, which is produced by the body during pregnancy, causes ligaments and connective tissue to become extremely lax and as a result your pelvis becomes hyper-mobile and even more unstable, often this hyper-mobility is not symmetrical - so pain can presents itself on one side more than the other
  3. The muscles of the butt can become tight, tonic and overworked during pregnancy as your pelvis changes to make room for the growing baby - pulling on one or both sides of the joints and causing pain
  • STOP ALL UNILATERAL WORK- this means you should no longer work one leg at a time. (All single leg side lying exercises – Clam Series, Side Butt series). Instead do some core stability work – The Fundamentals OR/& Bilateral work where you are working both legs at the same time. (Squats, Bridging)
  • STRETCH – muscles that attach to the sacrum can become extremely tight, further pulling on the SI Joints that are already vulnerable and causing pain.  Good ones include - Butt stretch, hamstring stretch, pinky ball release of Butt and deep ext. rotators of the butt
  • BALANCE YOUR PELVIS – When there is asymmetry there is pain in the pelvis. By working both legs at the same time in a slow, focused way the pelvis can often balance itself out and relieve the SI Joint pain
  • STRENGTHEN THROUGH STABILITY – Fundamental Core exercises and strengthening the deep external rotators of the hip isometrically will help stabilize the pelvis and eliminate the pain. 

Try some of these SI Joint workouts to relieve pain, strengthen the right muscles and balance the pelvis.