Anthropometric dimensions and overuse injury among Australian keyboard operators

Male and female rate differences in carpal tunnel syndrome injuries: personal attributes or job tasks?

Carpal tunnel syndrome (CTS) exacts a significant toll on the health and productivity of American workers. In 1996, 29,937 workers lost time from work due to CTS. Half of these were out for more than 25 days, compared to a median of 5 days for all injuries/illnesses. There are striking gender disparities in CTS rates. Overall, three times more women suffer from CTS than men. While some authors have emphasized the role of gender attributes in this risk disparity, the multifactoral causes of CTS, and the sex segregation of women into jobs with high-risk tasks, may be obscuring the work-related contributions to CTS risk. We argue here that men and women doing the same work tasks will have similar rates of CTS. To examine this premise, we used Bureau of Labor Statistics injury counts (numerator) and census data from the Current Population Survey (denominator) to determine injury rates of CTS for both men and women in six high-risk occupations: (1) assembler, (2) laborer-nonconstruction, (3) packaging and filling machine operators, (4) janitors and cleaners, (5) butchers and meat cutters, and (6) data entry keyers. Variable job tasks exist within five of the six high-risk occupational titles. Among those five, the male to female (M:F) risk rate ratio ranged from 0.29 to 0.50. However, the sixth occupational title, data entry keyers, which requires a single physical task, had a risk rate ratio of 1.06. This suggests that an equal risk between genders exists when the occupational tasks (exposure) are truly similar. Job task analysis unmasks potential biases that may wrongly attribute disproportionate CTS rates to gender attributes. This focus on gender attributes fails all workers because preventive interventions in the workplace are deferred. It fails women disproportionately because they are overrepresented in jobs at high risk for CTS.

An evaluation of the ergonomics of three computer keyboards

The influence of keyboard design on hand position, typing productivity and keyboard preference was evaluated by comparing two segmented alternative designs with the linear standard keyboard. The FIXED alternative keyboard featured a split angle of 12 degrees and a moderate lateral inclination angle of 10 degrees. The adjustable OPEN alternative keyboard was used with a 15 degrees split setting, which resulted in a marked 42 degrees of demiboard lateral inclination. Sixteen typists, who completed 10 h of training on both alternative keyboards, were videotaped while typing set texts on all three keyboards. Forearm and wrist angles based on three-dimensional video analyses were significantly different (p<0.05) among the three designs tested. Both alternative keyboards placed the forearm and wrist closer to neutral positions than did the standard keyboard. While the OPEN keyboard reduced pronation, it simultaneously increased radial deviation. The FIXED keyboard kept the forearm in moderate pronation and the wrist closer to neutral. More time was spent in neutral and moderate ranges of wrist motion when subjects typed on the FIXED compared with the other two designs. With respect to the standard keyboard, typing productivity was reduced by 10% on the FIXED and 20% on the OPEN designs. No significant difference in preference was found between the standard and FIXED keyboards, both of which were preferred over the OPEN. It was concluded that, of the three keyboards evaluated, the FIXED design incorporated moderate changes to the standard keyboard. These changes promoted a more natural hand position while typing thereby reducing the potential for cumulative trauma disorders of the wrist. In addition, the FIXED design preserved a reasonable level of productivity and was well accepted by users.

Gender trends in sick-listing with musculoskeletal symptoms in a Swedish county during a period of rapid increase in sickness absence

Sickness absence and disability pension due to musculoskeletal diagnoses has increased in Sweden.

STUDY OBJECTIVE

To study gender trends in sickness absence with musculoskeletal diagnoses and its changes in 1985-87.

DESIGN

A prospective population-based study of all new sick-leave spells exceeding seven days in 1985-87. Sickness absence with "all diagnoses" was compared to "all musculoskeletal diagnoses", the latter group was also divided into three sub-groups.

SETTING

The county of Ostergötland, Sweden.

PARTICIPANTS

All sick-leave insured aged 16-65; 107,000 women and 100,000 men.

RESULTS

More women than men were sick-listed in "all diagnoses" in 1985. There were corresponding gender differences in sickness absence with musculoskeletal diagnoses except with the diagnosis "low back pain". Sick-listing with musculoskeletal diagnoses increased for both women and men from 1985 to 1987, but the increase was consistently much higher for women, especially for younger women.

Occupational Overuse Syndrome/Repetitive Strain Injury: The Occupational Therapist's Role

This article outlines the intervention used in a specialised occupational rehabilitation clinic in New Zealand to treat and manage clients experiencing the symptoms of Occupational Overuse Syndrome (OOS). The government compensation agency accepts the syndrome as genuine and one that can be identified as a work-related injury; it therefore funds the treatment procedures. The article discusses the various explanations of OOS and goes on to outline the work of the clinic, the interventions it uses and the role of the occupational therapist in the treatment of the syndrome.

Pregnant women and working surface height and working surface areas for standing manual work

Physically loading aspects of work may have adverse effects on the health of both the pregnant woman and the unborn child. Improving the fit between the pregnant woman and the workplace layout contributes to minimizing the load associated with given tasks. The aim of this paper is to evaluate two layout aspects for standing manual work, namely working surface height and working surface areas, for the condition of pregnancy. Two approaches were used. (1) The effects of changed body dimensions were evaluated with regard to (a) fit problems while working at a workplace in accordance with common guidelines and (b) the validity of assumptions of these guidelines. (2) The appreciation of relevant aspects of workplace layout at a specific manual task was assessed. Twenty-seven women were examined in pregnant and non-pregnant conditions. The first approach showed that fit problems are likely: guideline working surface height is just (2-7 cm) under the most protruding abdominal point, and areas based on non-pregnant abdominal depth are relatively large in pregnant condition. Further, existing methods to assess working surface areas have various assumptions that are not valid in pregnant condition. The second approach showed that at a specific manual task, women in late pregnancy preferred a considerably lower table height than the common guideline heights. Possibly, abdominal height becomes a relevant design factor with regard to working surface height during pregnancy. The task position on the working surface at which effort started became closer to the table edge due to pregnancy. Both approaches show that common guideline working surface heights for manual work, and working surface areas assessed in non-pregnant condition seem not suitable in pregnant condition.