"When the piriformis hip muscle tightens up it can strangle the nearby sciatic nerve triggering buttocks pain that often shoots down the back of one leg," explains neurosurgeon Aaron Filler, MD, PhD. Filler, the author of a Cedars-Sinai Medical Center study that found that, for many people, a tight muscle in the hip causes Sciatica, suggests these pain-relieving exercises: Hip Twist Stretch Lie face-up with left leg out straight and right knee bent, right foot on floor near inside of left knee. Using left hand gently press right knee down and towards floor on left until you feel a stretch through buttocks and lower back. Your right hip and buttocks will come off the floor as you twist. Hold for 30 to 60 seconds. Repeat on other side. Frog Press Strengthener Lie face-down with pillow under hips. Fold arms and rest forehead on hands. Bend knees out to sides and place soles of feet together. Your feetand calves will be off the floor. Contract your abs and press soles together firmly for a count of 10. Relax and repeat 8 to 10 times. Source