It combines disciplines of study within the health and physical sciences; mathematics and materials engineering, gait analysis, anatomy and physiology, pathophysiology, biomechanics and psychology contribute to the work of orthotists (professionals in the field of orthotics). Patients benefiting from an orthosis have sustained a physical impairment such as a stroke, spinal cord injury or a congenital abnormality like spina bifida or cerebral palsy. Corrective shoe inserts are popularly known as orthotics. Certified pedorthic practitioners (known as pedorthists) are specialists in foot orthotics (pedorthics). Specialists of foot orthotics are not limited to C-Ped practitioners only. An orthosis is intended to mechanically compensate for a pathological condition. In the 1970s, an effort was put forth to classify orthoses by their function and acronyms describing the joints that are encumbered by the orthoses were proposed by a group of American professionals involved in the field of orthotics- from this effort sprung the current nomenclature : AFO- ankle foot orthosis, TLSO-thoracolumbosacral orthosis, WHO- wrist hand orthosis, etc. The nomenclature caught on, but the more tedious effort to describe the function of the orthosis; assist dorsiflexion at ankle, limit wrist flexion to 10 degrees, resist thoracolumbar rotation did not get as much mileage due perhaps to its semantic difficulty in prescription formulation.