Documents keyboard operations 13 results

"Obesity in the workplace is associated with loss of productivity, high medical care expenses, and increased rates of work-related injuries and illness. Thus, effective, low-cost interventions are needed to accommodate the size of today's obese office worker while alleviating potential physical harm associated with musculoskeletal disorders. Utilizing a sample of 22 overweight and obese office workers, this pilot study assessed the impact of introducing an alternative, more ergonomically-sound keyboard on perceptions about design, acceptability, and usability; self-reported body discomfort; and typing productivity. Data were collected using self-reported questionnaires and objective typing tests administered before and after the intervention. The intervention duration was six weeks. After switching from their standard work keyboard to an alternative keyboard, all participants reported significant decreases in lower back discomfort (t = 2.14, P = 0.044); although obese participants reported significant decreases in both upper (t = 2.46, P = 0.032) and lower (t = 2.39, P = 0.036) back discomfort. No significant changes were observed in overall typing performance scores from baseline to follow-up. Findings suggest that such interventions may be introduced into the workforce with positive gains for workers without reducing short-term worker productivity."

"Injuries and disorders caused by overexertion and repetitive motion are the leading causes of compensable lost-time cases in the United States. Epidemiological and laboratory-based research methods have been used to evaluate the significance of various risk factors associated with overuse injuries and disorders. The National Institute for Occupational Safety and Health performed a comprehensive review of over 600 epidemiological studies in 1997 and concluded that there was evidence of a causal relationship between workplace exposures to forceful exertions, repetition, awkward posture, and vibration and disorders of the neck, shoulder, and upper extremities. Although epidemiological studies provide important insights to understanding the causes of work-related overuse disorders,t hey are sometimes criticized for their inability to measure precisely how people respond to specific risk factors found in the workplace.
This article presents a review of recent laboratory studies and biomechanical models of work factors believed to be associated with increased risk of upper extremity injuries and disorders. Biomechanical models and laboratory studies do not replace epidemiological studies. However, these approaches provide important complementary information that is needed to understand the complex process of how exposures to physical risk factors result in strain that may ultimately lead to injury or disease. These studies also provide important insights as to how people react and respond to specific physical risk factors found in the workplace. Combined with epidemiological research, laboratory studies are an essential element in understanding the causes and prevention of work-related overexertion injuries."

"The relation between lipoatrophia semicircularis (LS--band-like circular depressions and isolated atrophy of the subcutaneous fatty tissue on the anterior thighs and sitting posture or pressure on the seat surface of office chairs was investigated in an office environment. A questionnaire was presented to 21 subjects and electromyographic measurements, video analysis and pressure measurements were performed. Remarkable posture differences between the LS group and the group without LS were found: less use of the lumbar support of the chair, static sitting postures and a too high seat surface of the office chair were characteristics of the subjects with LS. These observations were confirmed by higher pressure measurements for the subjects with LS. In addition, highly significant pressure differences were found between different chairs."

The effects of a downward-tilting (DT) keyboard tray on wrist posture, seated posture and self-assessed musculoskeletal discomfort were investigated in a field experiment. Thirty-eight professional office workers were studied. A pretest assessed how they typed using either a conventional keyboard on a desk or on an articulating keyboard tray, and with or without wrist rests. Workers were randomly allocated to a control (n=15) or test group (n=23) that used their existing keyboard in a DT system. A post-test was conducted 3 weeks later. Results showed no significant changes in wrist posture, seated posture or reports of musculoskeletal discomfort for the control group, and ~ 50% of typing wrist movements put the hand in a neutral zone. There were significant improvements in wrist posture, seated posture and upper body musculoskeletal discomfort for the test group using the DT system. Over 80% of typing wrist movements put the hand into a neutral zone with the DT arrangement. Reactions to using a conventional keyboard on a DT system were positive.

"Eighty computer users with musculoskeletal disorders participated in a 6-month, randomized, placebo-controlled trial evaluating the effects of four computer keyboards on clinical findings, pain severity, functional hand status, and comfort. The alternative geometry keyboards tested were: the Apple Adjustable Keyboard [kb1], Comfort Keyboard System [kb2], Microsoft Natural Keyboard [kb3], and placebo. Compared to placebo, kb3 and to a lesser extent kb1 groups demonstrated an improving trend in pain severity and hand function following 6 months of keyboard use. However, there was no corresponding consistent improvement in clinical findings in the alternative geometry keyboard groups compared to the placebo group. Overall, there was a significant correlation between improvement of pain severity and greater satisfaction with the keyboards. These results provide evidence that keyboard users may experience a reduction in hand pain after several months of use of some alternative geometry keyboards."