Review Study of Computer Input Devices and Older Users

The prevalence of arthritis is high, with osteoarthritis (OA) being one of the most frequent disorders in the population. In England and Wales, between 1.3 and 1.75 million people have OA and a further 0.25-0.5 million have rheumatoid arthritis (RA), while in France some 6 million new diagnoses of OA are made each year. In 1997, approximately 16% of the US population had some form of arthritis. This prevalence is expected to increase in the coming years, as arthritis more often affects the elderly, a proportion of the population that is increasing. The economic burden of such musculoskeletal diseases is also high, accounting for up to 1-2.5% of the gross national product of western nations. This burden comprises both the direct costs of medical interventions and indirect costs, such as premature mortality and chronic and short-term disability. The impact of arthritis on quality of life is of particular importance. Musculoskeletal disorders are associated with some of the poorest quality-of-life issues, particularly in terms of bodily pain (mean score from the MOS 36-item Short Form Health Survey of 52.1) and physical functioning (49.9), where quality of life is lower than that for gastrointestinal conditions (bodily pain 52.9, physical functioning 55.4), chronic respiratory diseases (72.7, 65.4) and cardiovascular conditions (64.7, 59.3).

What are the factors responsible for skilled typing performance, and do they change with the age of the typist? These questions were addressed in two studies by examining time and accuracy of keystrokes in a variety of typinglike activities among typists ranging in speed from 17 to 104 net words per minute and ranging in age from 19 to 72 years old. Typing skill was related to the temporal consistency of making the same keystroke, the efficiency of overlapping successive keystrokes, the speed of alternate-hand tapping, and the number of characters of to-be-typed text required to maintain a normal rate of typing. Older typists were slower in tapping rate and in choice reaction time but were not slower in speed of typing, apparently because they were more sensitive to characters farther in advance of the currently typed character than young typists.