One of the more commonly known medical specialties is orthopedics. The term generally refers to problems with the skeletal system, our bones, and the muscles and connecting tissues. There are any number of problems related to this system, from injuries that cause breaks to genetic problems that cause deformities to loss of bone density as people age. As a result, the average person will deal with an orthopedist at some point in their life, either because they are a patient or because someone close to them is. Because of the wide variety of problems related to bones, there are various specialties within the field of orthopedics.
Some doctors specialize in sports injuries, which is perhaps the most common type. Anyone who is even moderately active has probably gotten hurt playing sports, running, or lifting weights. Orthopedic injuries can also happen in car accidents, falls, or just stepping on your foot wrong. So there are many orthopedists who deal with broken bones and damaged joints. Some specialize even more, perhaps in shoulders, knees, or feet, and as a result you can find very knowledgeable doctors for some types of injuries. Orthopedic surgeons specialize in fixing these problems; sometimes they have to use metal plates, screws, and pins to fix bones in place so the injured bones and tissues heal properly; sometimes they have to remove tissue or bone from injured areas; sometimes they temporarily set the bone and remove hardware once the injury has healed.
Others specialize in genetic diseases that cause problems with bone development, like crooked spines. There are a multitude of problems that fall in the category of orthopedics, and just as many doctors to treat them.
Many people have probably been treated with orthotics.
Orthopedic supplies can be used to treat bone and muscle injuries.