Some tasks put carpenters at higher risk for low-back pain

In brief

An ergonomic analysis of job tasks in residential carpentry helped show which job tasks place the most stress on the spine.

Published: January 2007

Why was this study done?

Construction workers are particularly susceptible to work-related low-back pain. Some types of construction workers face unique hazards and different rates of pain. One such group is residential carpenters. Researchers sought to explore how different job tasks in residential carpentry put stress on the body, leading to possible injury. They also used computer software to identify postures that may put carpenters at risk of developing low-back pain.

How was the study done?

In a series of focus groups, 94 carpenters from the Denver, Colorado region were asked to describe the job tasks involved in building a wood frame house. Then, the carpenters answered a questionnaire about the physical difficulty of 44 of these tasks. Finally, researchers used computer software and the Ovako Working Posture Analysis System (OWAS) to analyze 10 of the 44 tasks for signs of stress to the low back.

What did the researchers find?

Among the carpenters, 38 per cent reported having low-back pain in the past year. All 10 of the job tasks that underwent ergonomic computer analysis carried some risk of injury to the low back. Seven tasks carried a significant risk. However, the job tasks differed greatly in the amount of pressure placed on the spine. The analysis showed that the task of “standing walls” placed the most strain on the spine. “Creating a cut list” of items needed for a project placed the least strain.

What are some strengths and weaknesses of the study?

Before this study, ergonomic analysis had not been used to evaluate job tasks in residential carpentry. Still, the results may not represent the average experience of carpenters in the United States. The reason is that the study sample was not randomly selected and may not represent all residential carpenters.