Overview of Ergonomic Assessment - Fundamentals and Assessment Tools for Occupational Ergonomics - page 674

Horizontal reach distance from spine

12 in.
24 in.

Healthy LBD Healthy LBD

10
15
20
25
10
15
20
25
10
15
20
25
10
15
20
25

Maximum
safe load
25 pounds

Shoulder

Maximum
safe load
50 pounds

Maximum
safe load
25 pounds

Waist

Knee

Floor

High risk

Low risk Medium risk

FIGURE 34.2 Guidelines for lifts involving trunk twisting angle of asymmetry between 30 and 60 8 (The angle

between the front of the body, when facing forward, and the load being lifted).

ACGIH TLV. In addition, the guidelines can be used by medical professionals to develop realistic rec-
ommendations for injured workers' capabilities, since capabilities can be related to characteristics in
the workplace. Also, transitional work providers can use the guidelines to place employees recovering
from LBDs in the right tasks at the right time. The tool can help return an injured worker to work as
soon as possible while minimizing the risk of aggravating an existing LBD.

34.4.2 Upper Extremity Assessment Tools
34.4.2.1 Strain Index
Moore and Garg (1995) developed a tool called the Strain Index to assess the risk of upper extremity
MSDs based upon physiological, biomechanical, and epidemiological literature. The inputs to the tool

Hor izontal reach distance from spine

12 in.
24 in.

Healthy LBD Healthy LBD

10
15
20
25
10
15
20
25
10
15
20
25
10
15
20
25

Shoulder

Maximum
safe load
42 pounds

Waist

Knee

Floor

Low risk High risk

Medium risk

FIGURE 34.3 Guidelines for lifts involving trunk twisting angle of asymmetry between 60 and 90 8 (The angle

between the front of the body, when facing forward, and the load being lifted).