Knee Leg Wedge Pillow Cushion for Side Sleeper Sciatica Relief or pillowcase. This cushion provides the perfect support for side sleepers and those with sciatica. It can be used to elevate the leg, reducing pressure on the sciatic nerve. The wedge is filled with hypoallergenic polyester fiberfill, which is soft and comfortable. It can be used to prop up the upper body or to provide support for the back, head, and neck. It is machine washable and dryable.