Generally, a stool is a chair with no back rest. But, there are stools with back rest. These stools are used in hospitals by surgeons or doctors while treating patients and hence referred as Surgeon Stool or Doctor's Stool. Frame work of  medical doctor stool is made of various materials like Iron, Steel, Stainless Steel, Erw Steel, Aluminum. The metallic frame of the medical doctor stool is painted or powder coated. Powder coating is of various types like epoxy coating, nylon coating, polyester coating or chromium plated etc. The surgeon stool top is revolving fitted with strong and accurate machine screw. Cushioned seat and back for comfort. The upholstery top is foam filled or fiber filled. The covering ranges from cloth to leather, rexine , vinyl to other synthetic fabric etc. hospital surgeon stools have semi sphere adjustable backrest for ergonomic elbow and body support. The base of the doctor stool can have three or four or five legs with leg rest which can be circular or square. There is integral gas cylinder, hydraulic or spring loaded for seat height adjustment. Doctor's stools with castors ensure smooth, safe and stable movement at all times.