Low back pain is currently one of the leading causes of disability in the United States. Current scientific evidence suggests an inverse relationship between trunk extension endurance static hold time (Biering Sorensen) and prediction of low back pain episodes. The specific aim in Phase I is to demonstrate the ability of a variable angle roman chair (VARC) training protocol to increase trunk extension endurance static hold time in healthy subjects. A VARC device will be produced for clinical, industrial, and home use settings. In Phase I, the VARC prototypes will be completed in order for training and rehabilitation protocols to be established. Safety in normal populations will be documented and low back endurance and strength gains will be determined. Information from focus groups composed of test subjects and health care providers will be gathered and assessed throughout the development of the VARC prototypes and protocols. Phase II studies will involve clinical investigations designed to determine if VARC rehabilitation protocols can significantly decrease low back pain in acute, subacute, and chronic low back pain populations. The possibility of decreasing incidence rates for low back injury in high-risk industrial settings will also be investigated. Data from these studies will be obtained through reliable outcome tools, objective strength measurements and injury occurrence demographics. This innovative VARC is projected to enhance the capability of health care providers to render effective, non-invasive, low cost rehabilitation options for the treatment and prevention of low back pain and disability. PROPOSED COMMERCIAL APPLICATION: The current costs for lower back injuries in the United States are immense. Due to the high incidence of low back pain, there are several large markets for this innovative VARC technology. The use of VARC rehabilitation protocols for the treatment and prevention of low back pain will be of value to medical providers, physical therapists and chiropractors. Additionally, other markets include HMO's, PPO's, high risk populations, military personnel and home users.