Study design: The study group consisted of 131 female nursing aides who took part in an intervention program with physical training or education. Assessments were performed before the intervention program and after 6 months. At follow-up evaluation, 91 nursing aides remained in the study.
Objectives: To examine if perceived physical exertion was a risk indicator for low back symptoms, and to examine the relationship between perceived physical exertion, aerobic capacity, back endurance, psychological demands, and job control.
Summary of background data: Perceived physical exertion frequently is assessed in epidemiologic studies concerning low back symptoms. More information about the relationship between perceived exertion, other potential risk indicators, and symptoms may provide opportunities for effective prevention of symptoms.
Methods: Assessments were obtained by questionnaires and physical capacity tests.
Results: The nursing aides who reported high physical exertion and were 45 years of age or older were at greater risk in the follow-up period for reporting new symptoms, continued symptoms with the same intensity, or more intense symptoms from the low back (rate ratio, 3.01; 95% confidence interval, 1.1-8.2). The exposure variable correlated most strongly (r = 0.4) with perceived physical exertion was psychological demands.
Conclusions: The results indicated being aged 45 years or older, combined with high perceived physical exertion, was a risk indicator for low back symptoms. A relationship between perceived physical exertion and psychological demands was observed, but there was no influence of physical capacity on perceived physical exertion.