SMARTWheels: development and testing of a system for measuring manual wheelchair propulsion dynamics.

The purpose of this project was to develop a system for dynamically sensing pushrim propulsion forces and torques and to collect kinetic data with the device. A system was developed to detect the forces and torques applied to the wheelchair pushrim, record, store, and process the measured data, and display the kinetic information for analysis. Ten adults, including four male wheelchair users, three ambulatory men, and three ambulatory women, pushed a wheelchair with the SMARTWheel on a dynamometer while their kinematics were videotaped. The kinetic data collected with our wheel were correlated with stick figure representations of digitized kinematic data obtained through video analysis. The close agreement between the kinetic results and the Kinematic results provided a temporal validation of the ability of the wheel to detect forces and torques applied to the wheelchair pushrim. The recorded forces and torques were in agreement with previously reported magnitudes.

Design of a composite monocoque frame racing wheelchair.

Design of present-day racing wheelchairs developed out of necessity and common sense. The chairs first used in racing were everyday chairs; through years of trial and modification the racing chairs of today evolved. Very little advanced engineering has been applied to the design of racing chairs. The Finite Element Analysis model executed on a computer provided insight into structural problem areas in the design of unibody frame racing chairs. Slight modifications to the model can be used to investigate new shapes, loads, or materials without investing large amounts of time and money. Wind tunnel testing with scale models provided perspectives on different improvements to reduce drag. Shape improvements may play an important role in reducing the racer's time during competition. Shape may help to decrease drag for the user in either the upright or down position. Considering that the frontal area increases around 30% in the up position with current strut and chassis frames, monocoque shapes should excel. Finite element analysis and air drag analysis are important to the design of a composite racing wheelchair. Composite materials may promote more efficient and ergonomic racing wheelchairs.

Wheelchair armrest strength testing.

There are about 1.4 million manual wheelchair users, 100,000 electric-powered wheelchair users, and 60,000 electric-powered scooter users. The current study was undertaken to determine if the fasteners of a clamp-type armrest receiver were prone to failure. The first test was used to examine the potential misalignment of the armrest receiver components that attach it to the frame. The second test was to evaluate the entire armrest using the American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society of North America armrest static strength standard. Finally, we conducted three fatigue tests. The first fatigue test was performed by repeating the static stability tests multiple times. The last two tests were a modified version of the double-drum wheelchair fatigue test used to apply repeated loading and vibration simultaneously. A paired t-test showed that there is no statistically significant difference (p = 0.08), with a confidence of 95%, between critical alignment measurements. The armrest including the receiver passed the standard requirement of a force of 760 N being applied outward at 15 degrees. During fatigue testing, we found that armrests did not exhibit any visible or functional damage. Upon completion of the tests, the armrests and receivers functioned properly. At about 100,289 cycles on a double-drum test machine, three bolts failed on each armrest receiver when the screws were loosened to have only five threads engaged prior to commencing the test. The design of the armrest tested was in compliance with existing national and international standards. Currently, both International Standards Organization and American National Standards Institute/Rehabilitation Engineering and Assistive Technology Society committees are developing standards for seating systems that will include static, impact, and fatigue strength testing of devices like lateral torso supports, lateral hip support, etc. Methods similar to those explored in this study should be considered. This study may help manufacturers when designing products and purchasers or regulatory agencies when attempting to evaluate the safety and quality of armrest assemblies.

["Desensitization" technique in the rehabilitation of the painful hand]. / Techniques de "désensitization" dans la rééducation de la main douloureuse.

Hand injury patients fairly frequently develop, soon after the injury, hypersensitivity phenomena on contact of the hand with the environment, which may lead to exclusion of the hand. The authors attempt to explain this syndrome on the basis of the pathophysiological theories concerning pain. American authors have proposed an original desensitization treatment based on simple and varied techniques, which provides extremely encouraging results.