A coccyx cushion is a seat cushion with a wedge removed in the center back. This allows the bottom of the spinal cord or tailbone, the coccyx, to sit without coming into contact with the seat cushion. This elevation of the coccyx aids in reducing pain and discomfort for persons with pain in this area. Making a coccyx cushion is well within the capabilities of most people who can sew using a sewing machine. Most coccyx cushions are made of foam and they are covered with a pillow case designed for the cushion. This makes the cushion cover easier to clean in the laundry without having to wash the whole cushion.
Select a piece of 5 to 10 cm (2 to 4 inch) foam the size of the chair seat. Foam thickness varies from personal preference, so choose what feels best for your needs.
Measure the back width of the cushion and find the centre point. Measure 7.5 or 10 cm (3 to 4 inches) on either side of the centre point. Measure vertically along the centre point line 15 to 20 cm (6 to 8 inches) and mark. Measure 5 to 7.5 cm (2 to 3 inches) on either side of your second centre point mark. Draw a line with your marker from the edge of the cushion marks to the inner marks. This should create a wedge shape from 10 to 15 cm (4 to 6 inches) on the small side to 15 to 20 cm (6 to 8 inches) on the back and wider side. How big you make your wedge or cut out depends on your needs.
Cut the foam along the lines using an electric knife. Remove the waste.
Fold your fabric in half, facing sides together. Place your cushion over the fabric. Draw around the cushion, adding a 1.2 cm (1/2 inch) seam allowance to all sides. Cut your fabric. Measure the height of the cushion, add 2.5 cm (1 inch) and cut a strip of fabric that will fit around the entire perimeter of the cushion. You may need to seam the fabric together at some point.
Place your cushion cover top and your side fabric face sides together and pin a 1.2 cm (1/2 inch) seam all around. Sew the fabrics together. Seam the sides together where they meet up using a 1.2 cm (1/2 inch) seam.
Align your cushion cover bottom with the top, face sides together. Pin the side fabric to the cushion cover bottom starting at the bottom left corner, up and around the shaped top edge and back down the right side. Leave the bottom edge open. Sew a 1.2 cm (1/2 inch) seam where you have pinned.
Cut hook and loop tape to fit along your cushion opening. Sew one half of the tape to the side fabric and one half to the bottom cover fabric. Turn your cover right side out. Slip your cover over your cushion and you are ready to use it.
Most people make several coccyx cushions at the same time so they have one for the car, the dining room, the living room and the bedroom. Often the covers are interchangeable.