An Assessment Technique for Postural Loading on the Upper Body (LUBA) - Fundamentals and Assessment Tools for Occupational Ergonomics - page 811

43
An Assessment
Technique for Postural
Loading on the Upper
Body (LUBA)

43.1 Posture Classification Scheme . ............... 43-1

43.2 Objectives . .............................. 43-2

43.3 LUBA ................................... 43-2

Relative Discomfort Scores by Joint Motions † Posture
Evaluation Procedures

Dohyung Kee
Keimyung University

Waldemar Karwowski
University of Louisville

43.4 Application Example ....................... 43-7

43.5 Conclusions .............................. 43-7

43.1 Posture Classification Scheme

The relationship between awkward working postures and the risk of musculoskeletal disorders (MSDs)
has been widely studied in the past. For example, van Wely (1969) discussed the relation between
inadequate work postures and probable sites of pain, and Armstrong et al. (1993) reported a comprehen-
sive review of epidemiological studies examining the relationship between work postures and (MSDs).
Heinsalmi (1986) and Burdof et al. (1991) pointed out that a significant relationship was found
between poor working postures and musculoskeletal-related lost workdays or low-back disorders. Bhat-
nager et al. (1985) indicated that a working posture affects postural discomfort and inspection perform-
ance for printed board reproductions.
Awkward, extreme, and repetitive postures can increase the risk of musculoskeletal disorders. There-
fore, cost-effective quantification of the magnitude for physical exposure to poor working postures is
important and needed, if the potential for injury as a result of postures is to be reduced (Andrew
et al., 1998). Since development of the posturegram, a technique for numerically defining a posture pro-
posed by Priel (1974), various postural classification methods have been developed to identify and quan-
tify postural stress during work. These schemes can be classified into two basic categories depending
upon the methods used for quantifying postural stresses: instrument-based and observational tech-
niques. The latter is more widespread in industry, because it does not interfere with the worker
during observations, and does not require use of expensive equipment for estimating the angular devi-
ation of a body from the neutral position (Genaidy et al., 1994). The instrument-based method using
bioinstrumentation such as electromyography has been rarely used as a major tool for quantifying pos-
tural stresses in industry, because it is expensive, obtrusive, and limited due to the nature of the

43-1