Let's do a press-up.
This is a range of motion stretch directed at the SI joint.
And, to come into this, you'll come face-down on your mat or the ground with your hands just underneath your shoulders.
Gently press your torso up off the ground, keeping your hips down, and hug in the low belly to protect your spine.
Now, if it's uncomfortable to have your arms straight, you can give a microbend in the elbows here.
And hold yourself up for about 5 seconds, keeping the glutes and the low back relaxed.
Lower yourself down carefully.
And try and work yourself up to 10, or 15, or 30 seconds. Once you get up to 30 seconds, you can do about 10 reps of these.
That was the press-up.