Lever Propulsion Attachment for Pushrim Wheelchairs

DESCRIPTION (provided by applicant): An innovative lever propulsion attachment for pushrim wheelchairs has been developed. This design promotes a natural and efficient propulsion motion which can eliminate injuries of the shoulders, elbows, and wrists experienced by the majority of the 1.4 million pushrim wheelchair users in the United States. It can also be utilized by more functional electric wheelchair users, enabling them to avoid the health problems associated with a sedentary lifestyle. The design utilizes a single lever in front of the user's knees to drive the front wheel. Steering and braking is by a standard bicycle interface, with the entire drive unit rotated for steering in much the same manner as handcycle propulsion attachments. The advantages of lever propulsion over handcycle propulsion are that less range of motion is required of the shoulder, arm, and wrist, and the user can utilize the part of the propulsion stroke appropriate for their disability. The proposed design is also considerably more lightweight, compact, and maneuverable than handcycle designs. The advantages of attachment designs over dedicated design are that effective use can be made of existing pushrim wheelchairs and users can revert to pushrim functionality when appropriate. In Phase I the propulsion mechanism, the most innovative and critical part of the design, will be tested according to clear functionality and robustness criteria. The stability of the design will also be verified. Phase II will include the development of the gear change, braking, and suspension systems, the attachment to pushrim wheelchairs, and comprehensive user testing.