If you have pain related to the two sacral-illiac joints that sit above and to either side of your tailbone, you will know it. The SI joints become loose from car accidents, impact to the sacrum or low back, from childbirth, or from sports injuries. You might feel pain near the two bony landmarks, or it can run across the low back laterally or radiate to the front of the pelvis. Serious SI joint injury will prevent you from sitting down in a chair and requires professional medical assessment.
Leg Abductors
Stabilize an SI joint injury after you have been given medical clearance. Working the legs by using a leg abduction machine at the gym is appropriate. By doing so, you will strengthen the gluteus medius muscles that are on the sides of the hips; these help stabilize the sacrum and SI joints to reduce pain. Sitting in the seat of the leg abduction machine, select a very low weight, such as 10 or 20 pounds to start. There will be small dividers that are on the outside of the kneecaps: when you move the legs apart, the resistance from the weight will strengthen the gluteus medius muscles. Slowly do seven to 10 reps for two sets. Do fewer if you cannot do more than 10 reps without strain.
Adductors
Work the opposing muscle groups of the gluteus medius, the adductor muscles of the inner thigh. Sitting in the seat of the leg adductor machine, select a low weight, such as 30 pounds. Adjust the leg setting so that your legs move apart and form a V-shape. Using the inner thigh muscles, bring the legs together. Do seven reps for two sets. Doing both exercises will create stability in the gemelleus muscles that form a "hammock" inside the pelvis to reduce SI pain. These exercises also strengthen obturnator externus and internus, the muscles that line the inner hip joint.
Practice Bridge Pose
Practice a Bridge Pose (Setu Bhandasana Sarvangasana) from yoga to further set and keep the SI joints healthy. Lie on your back on a mat or thick towel so the feet are flat hips-width distance apart and knees bent and stacked over the ankles. Lift the hips and bring your hands underneath the back, interlacing the fingers and extending arms to straight as you aim your tailbone away from the neck. Draw the inner thighs downward to widen the sacrum. Remain for a few breaths before lowering the hips to the floor to rest. Repeat once more with a rolled-up towel between the inner knees or a light foam yoga block and remain for five breaths: this works both gluteus medius and adductors. Rest.
