<< Back to CCN Newsletter - Summer 2007

Continued Testing of Alternate Work Postures for people with LBP

CATEA researchers looked at comfort and typing performance for people with and without chronic low back pain (LBP). The initial tests indicated a need to focus on upper arm support. Our research continued this Spring with several volunteers participating in another round of testing. Previous tests focused on maintaining a consistent relative position between the user, the keyboard and the monitor in each of five different postures, ranging from upright to fully supine (i.e., lying on one’s back). This time, an effort was made to keep the participants as comfortable as possible while they performed the prescribed typing tasks in each of the same postures.

Typical seated position for work at a computer

Although the results have not yet been fully analyzed, preliminary results indicate that there is a significant improvement in comfort with relatively minor adjustments to key components. Adjustment of the keyboard or the upper arm supports for example, can mean the difference between a noticeable amount of discomfort and no discomfort at all. Another preliminary finding indicates that the use of a cushion to provide additional support to the user’s forearms can prevent upper arm discomfort.

This is particularly beneficial in the supine postures where gravity tends to pull the arms in toward the body. The support reduces the need for the user to exert his or her shoulder muscles to externally rotate the forearm against the forces of gravity.

As with our previous studies, some of the participants for this study report that they typically have difficulty sitting and working at a regular computer for 1 hour or less without discomfort. In spite of the fact that the protocol for this test requires up to 2 hours of computer operation, preliminary analysis suggests that there is no significant increase in back discomfort throughout the duration of the test. This supports the idea that people with chronic LBP can find relief (or not exacerbate their condition) by working from significantly reclined or supine postures.

Supine position with monitor overhead

The results to date indicate that, while alternate postures can benefit people with chronic LBP, there is still the need for research in ergonomics relating to these alternate postures. A few small adjustments made a significant difference in the ability of users to operate the computer comfortably for fairly intense typing tasks (such as completing a series of timed typing tests). Most computer related tasks may not require such intense typing operations.

Contact

Scott Haynes, Research Engineer, CATEA, WorkRERC
scott.haynes@coa.gatech.edu