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EVALUATION OF HUMAN MOTOR CHARACTERISTICS
IN DRIVING A WHEELCHAIR WITH HAND-RIMS

Yuki OHTA, Hironobu UCHIYAMA and Junichi KURATA

Department of Mechanical System Engineering, Kansai University
3-3-35, Yamatechou, Suita, Osaka 564-8680, JAPAN

ABSTRACT

A self-propelled type of wheelchair with hand-rims has a good drive assembly that is human operator
and offers the convenience of mobility. The wheelchair propulsion of this type, however, causes
fatigue to the operator. As a solution of this problem, wheelchairs, which are equipped with a power
assist control system, are needed. In this research, the model based on the quantitative
human-wheelchair system was proposed for establishing its design manual. The major factor to be
considered was the influence of propelling force to the velocity of wheelchair caused by their inertia.
The subject participated in a follow-up test in order to adjust the velocity of the wheelchair to the
reference velocity. The motor characteristics of operators in driving a wheelchair was described in
detailed with results of evaluation by using the special designed test machine.

KEYWORDS
Human-machine system, Power assist, Human behavior, Wheelchair propulsion

INTRODUCTION

A self-propelled wheelchair is one of useful assistive device in the user's life. Moving with it gives
many people, who have difficulty to walk, not only the convenience but also the motivation to improve
their own quality of life (QOL) and activity of daily living (ADL), and expands their field of activities
as motivation increases (Bengt (1993)). Long travel and drive, however, have potential for fatigue
because of its propelling operation form. Propelling operation with hand-rims requires especially
longtime and cycling motion of upper-limb and puts too heavy physical burden on their muscle,
reported by Rodgers et al (2000). For these reasons, recently a self-propelled wheelchair with an
electric power-assist function is still getting more and more popular to maintain their own QOL and
reduce fatigue.

An electric power-assist function for the wheelchair has to work to their needs of propelling motion
and reduce their physical fatigue. The upper-limb fatigue have been researched. Fatigue is caused
from the propelling operation that the operator generates the propelling force, reported by Cooper
(1998) and Rodgers et al (2003), and the operation with the motion such as hold and release should be