biochemistry, genetics, molecular biology, pharmacology, engineering and physical sciences, social and behavioral sciences, and health sciences. Genetics and molecular biology, for example, offer powerful investigative techniques that can be used to provide an understanding of the causes and nature of some inherited disabling diseases. This area of research also holds promise for generating biological markers and animal models for these diseases, as well as the means for replacing or restoring the functions of defective or missing genes. Genetics research may also lead to the development of the capacity for regrowth of cells, organs, or limbs.
One of the contributions of engineering to rehabilitation science and engineering is within the realm of creating altered, supportive environments (external or internal) for people with disabling conditions. These engineered environments limit or reverse the functional manifestations of pathology and organ impairment by compensating for or replacing the altered or lost function with engineered structures and devices. The majority of current rehabilitation engineering research is in the fields of material sciences, biomedical engineering, and engineering technology development. Research in the development of prosthetics and orthotics, implantable lenses and pacemakers, and implantable drug delivery systems are some examples of engineered devices that reduce or eliminate impairment and improve function.
Recent findings in neuroscience and medicine hold promise for helping prevent and reverse neurological impairments, which are major causes of disabling conditions. Many of the therapeutic advances in this area have centered on preventive, regenerative, and restorative therapies for spinal cord and brain injuries. For example, a number of drugs given shortly after traumatic brain or spinal cord injury can significantly improve neurological recovery. Other compounds have been shown in laboratory and animal studies to foster the regeneration of severed spinal cord tissue and restore lost motor functions. An understanding of the neuronal control of skeletal muscle contractions should also prove to be useful to researchers trying to artificially mimic that control with electrical devices for individuals with paralysis. Pharmacological and physical therapies for relaxation of skeletal muscles also are being developed and show promise for relieving the prolonged and often painful muscle contractions associated with various disabling conditions. In addition, recent studies with animals suggest that recovery of function of muscles atrophied as a result of a lack of use due to injury or illness is possible with appropriate exercise.
Functional limitation is the expression of a potentially disabling con-