The development of a lever propelled mobility device is important to the health, safety and quality of life of wheelchair users. Past research has found lever driven wheelchairs to have superior mechanical efficiency, however due to design limitations, these chairs have not been integrated into everyday use in the United States. Lack of use may be due to design flaws that makes mobility difficult and ineffective. The development and refinement of the RoChair and RoTrike, both lever drive mobility devices, have the potential to increase usage of lever technology and preserve independence and quality of life of wheelchair users. Lever driven wheelchairs have the potential to reduce the development of repetitive strain injury (RSI) caused by wheelchair propulsion. Manual wheelchair (MWC) users are at high risk for the development of RSI due to the combination of high forces associated with and the repetitive nature of wheelchair propulsion and the extraneous positioning of the upper limb joints. Between 49% to 73% of full time MWC users report carpal tunnel syndrome (CTS) symptoms and 31% to 73% report shoulder pain. Upper limb pain and dysfunction have been found to be related to decreased quality of life, independence limitations and increased financial burden. A variety of powered mobility devices are available, however they can be bulky, difficult to transport and expensive. The ROTA mobility devices make use of effective lever drive technology, but have modified the design to increase acceptance with wheelchair users and be useful in everyday environments. Instead of adding on two levers to an existing wheelchair, ROTA devices integrate the lever in the design of the wheelchair enabling for one single push-pull lever mounted in the center to facilitate a rowing motion. Rowing activity balances musculature around the shoulder reducing the risk for RSIs. The integrated lever reduces the width of the chair, puts the upper limb in an effective position for propulsion and makes propulsion easier and more intuitive. ROTA has developed a quick release mechanism to allow the chair to be easily propelled in reverse, a significant improvement over other designs. Moreover, because ROTA is an integrated system the design has been optimized to facilitate transfers by locating the drive wheels under the seat and providing a release mechanism for the lever to be moved out of the way. The proposed research study intents to gather feedback from wheelchair users and clinicians about the lever drive mobility devices. Feedback will allow designers to modify and refine the devices based on user's likes, dislikes, needs and abilities. In addition, stability and durability of the ROTA mobility devices will be tested to determine if they can withstand everyday usage in a home and community setting.
Manual wheelchair users often develop repetitive strain injuries due to overuse of the upper limb during wheelchair population. Power mobility devices reduce strain but can limit the individual's physical activity level, independence and quality of life. A lever propelled device developed using participatory design processes will allow us to realize their potential as an everyday wheelchair or supplemental device for outdoor use or exercise and revise the design as needed so that they can be well integrated in the marketplace.
