This paper examines the complex relationship between the presence or absence of work-related back pain and other intrinsic and extrinsic factors such as manual lifting and proper training. By analyzing the weight lifting activities of 37 female nurses working in a geriatric ward, it was found that in the 7 day study period, total weight lifted not according to any recommended models was the single most significant variable associated with work-related back pain. Factors leading to the use of non-recommended methods were patient's cooperation, nursing category, and number of nurses lifting together. The effects of all variables on work-related back pain were found to be indirect, through improper load handling. Copyright © 1993 Published by Elsevier Ltd.