Orthotics is the design, fabrication, fitting and use of custom-made and off-the-shelf braces. These braces are designed to provide external support to areas such as knee, spinal, neck and cervical braces and foot orthotics. These devices are designed to treat such things as weakened or injured joints and/or muscle groups. Musculoskeletal disorders are ailments of the back, extremities or joints caused by traumatic injuries, chronic conditions, diseases, congenital disorders or injuries resulting from sports or other activities. In some instances, it is necessary to design and fabricate a custom orthosis for a specific need. The orthotist also may custom fit an off-the-shelf device to the patient's dimensions, or incorporates additional components to achieve the desired results. An orthosis may be worn temporarily until a weakness or injury is overcome, or on a permanent basis to facilitate impaired function due to a congenital or degenerative condition.