Figure 4 is one of the best stretches for piriformis and easing sciatica and lower back pain. To perform this stretch, find a comfortable seated position with your legs extended in front of you. Cross your right leg over your left and place your right foot on the ground. Bring your left knee towards your chest, and hold that position for 20-30 seconds.Then, slowly lower your left knee back to the ground, and repeat on the other side. You can also hold the stretch for as long as you can without s