Electromyographic activity of the erector spinae: The short-effect of one workday for welders with nonspecific chronic low back pain, an observational study.

Objective: This study aimed to evaluate the effect of one workday on pain and perceived exertion, muscular strength, and electromyographic activity of the erector spinae muscles in welders with and without low back pain. This is an observational cohort study.

Participants: Twenty-two welders, metallurgical shipbuilding, were equally divided into 2 groups: low back pain and no low back pain.