Your sacroiliac (SI) joint is where your sacrum (base of your spine) joins your iliac crest (part of your pelvis). Like other joints, it can be injured or may degenerate, causing pain usually on one side of your lower back, or in one of your buttocks or legs. It may not always be clear whether the pain is arising from an SI joint or other back problem.
It might be that weakness or tightness in the muscles around the sacrum and pelvis is causing your symptoms.
Exercises to strengthen these muscles include:
- hip abduction – lifting your leg out to one side
- hip adduction – putting a soft ball between your knees and squeezing
- bridge – lie on your back in with your knees bent and lift your pelvis up into the air
- triangle pose – yoga side bend pose
- table top – kneel on all fours and alternately lift opposite arm and legs pairs up in line with your back
Exercises to stretch these muscles include:
- hamstring stretch – sit on a chair, stretch out one leg and bend forwards reaching towards your toes
- quad stretch – stand holding on to the back of a chair for support, then bend one knee and holding your foot or ankle, draw your leg behind you, heel towards buttock
- hip adductor stretch – sit on the floor with your legs apart, keeping them as straight as you can, gently lean forwards towards your toes
- half-cobra (lower ab’s stretch ) – lie on your front, bend your arms like a Sphinx and raise your upper body away from the floor
- hip flexor stretch – lie on your back, bend one leg and pull it towards your chest as your straighten the other, pressing the back of it towards the floor
These exercises may be included in your Pilates class and your teacher can help you perform them correctly. However, Pilates teachers are not qualified to diagnose any medical condition. If you are in any doubt of the cause of your pain, then please contact your GP or physiotherapist.
You can read more about the SI joint and the above exercises on this spine heath website.