Content » Vol 19, Issue 4

Original report

Relative Mechanical Load on Back and Hip Muscles in Standing Position When Handling Materials Manually. A Study of Packing Work

O K Svensson, G Németh, J Ekholm
Department of Anatomy, Karolinska Institute, Stockholm, Sweden.
DOI: 10.2340/165019778719159168


Muscular load on the back and hip muscles was quantified and compared using a muscular strength utilization ratio (MUR). The MUR was obtained by dividing the total moment about the bilateral joint axis by the counteracting maximum muscular strength at the same joint angle. 72 different postures during simulated packing work were studied, with different combinations of box size, angle, edge height and weight. The MUR was calculated for a large, an average sized and a small man depending on whether they were all either strong, of average strength, or weak, thus giving nine MUR values for each posture. For a weak man, the MUR exceeded 100% in many postures. The largest box at a zero- or 30-degree angle to the horizontal with its upper edge 20 cm below elbow height gave the highest MUR, while the smallest box angled at 90 degrees with the upper edge 10 cm above elbow height gave the lowest. The presented concept of relating joint load to strength is proposed for use in preventive ergonomic counselling and in vocational rehabilitation.

Lay Abstract


Do you want to comment on this paper? The comments will show up here and if appropriate the comments will also separately be forwarded to the authors. You need to login/create an account to comment on articles. Click here to login/create an account.