Stretching to relieve tension on the sacroiliac joint reduces pain but there is also a link between dehydration and joint pain. Just stretching might not be enough if you are not giving your body enough fluids. Also, muscle imbalances contribute to pain in the SI joint too so stretching some sides and strengthening others with strength training exercises may be necessary in addition to stretching exercises.
Drinking Water
Everybody drinks water but because water is essential for every system in your body, including the organs cells and tissue, it is necessary to drink enough. The fluids around your joints are essentially water, as is your saliva. Therefore, dehydration can actually cause achy joints even in the SI joint. Eight glasses of water is the minimum you should drink, but those glasses must be 8 oz. full. Drink more water when you exercise if you are overweight or live in a hot climate.
Lying Backbends
When you have pain in the SI joint, the first task is to stabilize the back of the pelvis with strengthening exercise. Lying backbends accomplish this goal. The yoga pose salabhasana, or locust pose, is one of the most effective exercises for stabilizing the pelvis. It also stretches the chest, abdomen, shoulders and quadriceps. Start the exercise by lying on face down with your arms next to your sides palms up. Bring your legs together. Then, bend backwards to raise your shoulders toward the ceiling. The head, chest, arms and legs lift toward the ceiling. Imagine lengthening through the spine and extending back through the legs so you do not compress your SI joint and lower back.
Forward Bends
Once the pelvis is stable, the next step to relieving SI joint pain is stretching the lower back and pelvis. Forward bends accomplish that goal. An effective forward bend is the paschimottanasana, or seated forward bend. To perform this exercise, sit on a thin pillow and position your legs straight in front of you. Turn your thighs in slightly and push down into the floor. Then, incline forward from the hip joint and try to touch your chest to your thighs. Inhale and raise up slightly, then exhale and go deeper into the stretch.
Stretching the Back of the Pelvis
Twisting poses are also useful for reducing pain in the SI joint. This especially is true if one side of the back of your pelvis is tight, which causes a painful imbalance. A stretching exercise for this is ardha matsyendrasana, or half lord of the fishes pose. To perform this exercise, sit with your left leg bent sideways on the floor and your right leg crossed over the left with the right foot on the floor next to the left knee. The right knee points to the ceiling. Tuck your left foot against your right glute. Then, reach your right hand onto the floor onto the floor slightly behind you with your arm and back straight. Push against the outside of your tight knee with your left knee to twist right. Repeat on the other side. If one side is tight but the other stretches easily, only stretch the tight side and ask a personal trainer or physical therapist for strengthening exercises for the flexible side.
