Demographers expect the number of older persons to double to 86.7 million - or to 20.6% of the US population - by the year 2050. As has occurred over the past decade, the health care costs associated with older age are expected to steadily increase approximately 2% per year causing both a public health and personal burden. A key component to reducing health care costs and maintaining well-being in older persons is preserving physical function throughout the lifespan. The challenge to this objective is to combat the origin of the loss of physical function through treatment of chronic disease conditions. Another approach is to enhance physical function despite the occurrence of comorbid conditions through enhancement of the neuromuscular system. The neuromuscular system provides the necessary components for all locomotion, and is thus a logical choice for preventative therapies to target. This article will give a general overview of the models and risk factors that explain the development of physical disability.