Determination of the in vivo loading of the lumbar spine with a new approach directly at the workplace--first results for nurses.
OBJECTIVE
To determine the magnitude of workplace loading for nurses with and without a history of low back pain.


METHODS
A measurement system for the assessment of workplace loading as well as a model for the calculation of lumbo-sacral junction loading was designed and applied to a group of 12 nurses with and without a history of low back pain.


BACKGROUND
Disagreement exists regarding the key factors in the aetiology of low back pain. Traditionally workplace loading is viewed as the dominant influence. Data for workplace loading in jobs with non-uniform tasks, however, do rarely exist.


METHODS
A three-dimensional inverse-dynamic and force distribution model as well as the respective data acquisition system was used to assess the workplace loading of 12 nurses from surgical departments of two hospitals. The nurses were assigned to two groups based on their history of low back pain (with/without). Workplace loading was measured continuously for 4 h.


RESULTS
No differences in workplace loading between nurses with/without a history of low back pain were found. Maximum values of the compressive force at the lumbo-sacral junction were high and well above suggested workplace load limits. High values occurred only during short-time periods (about 0.4% of total shift duration).


CONCLUSIONS
A system for the assessment of overall workplace loading has been developed. First results for nurses suggest that critical loadings do exist at the workplace, even so they might not be the decisive factor for the development of low back pain.


CONCLUSIONS
Preventative measures for low back pain in nursing have to include prevention of critical workplace loading. This approach by itself, however, is probably not sufficient.
Biomechanics Section, Technical University Hamburg-Harburg, Harburger Schlossstrasse 36, 21079, Hamburg, Germany. morlock@tu-harburg.de
M M
MM
Morlock
V
V
Bonin
G
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Deuretzbacher
G
G
Müller
M
M
Honl
E
E
Schneider
D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D004576:Electromyography; D004867:Equipment Design; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000502:physiology*; D008297:Male; D008433:Mathematics; D018482:Muscle, Skeletal / Q000502:physiology; D009726:Nurses; D009784:Occupational Diseases / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted; D013314:Stress, Mechanical