Validity of pressure pain thresholds in female workers with and without recurrent low back pain
- 175 Downloads
Recurrent low back pain (LBP) is a common pain condition in elderly workers in a variety of occupations, but little is known about its origin and the mechanisms leading to an often disabling sensation of pain that may be persistent or intermittent. In the present study we evaluated the pressure pain thresholds (PPTs) in subjects suffering from recurrent LBP, as well as in healthy controls, to investigate if recurrent LBP is associated with an increased sensitivity of the muscular and ligamentous structures located on the lower back. One hundred and six female workers, aged between 45 and 62 years and working either in administrative or nursing professions were examined. The subjects were classified into LBP cases and controls based on the Nordic questionnaire. Subjects indicating 8–30 or more days with LBP during the past 12 months were graded as cases. PPTs were measured on 12 points (six on each side of the body) expected to be relevant for LBP (paravertebral muscles, musculus quadratus lumborum, os ilium, iliolumbar ligament, musculus piriformis and greater trochanter), as well as on a reference point (middle of the forehead) using a digital dolorimeter. The PPTs on all points on the lower back highly correlated with each other and a high internal consistency was found with a Cronbach alpha coefficient > 0.95. There was a moderate and significant correlation of the PPT on the forehead with the PPT on the lower back with correlation coefficients ranging from 0.36 to 0.49. In LBP cases from administrative professions, the PPT on the forehead was significantly decreased (P < 0.05). The PPT on the lower back did not significantly differ between the four groups studied, namely nurses and administrative workers with and without recurrent LBP. These results give evidence that recurrent LBP is not associated with an altered sensitivity of the muscular and myofascial tissues in the lumbar region. Furthermore, they raise questions about the value of reference point measurements in recurrent LBP.
KeywordsPressure pain threshold Low back pain Reference point
The authors wish to thank Prof. R. Merletti for managing the European cost shared project NEW (Neuromuscular assessment in the Elderly Worker, contract Nr. QLRT-2000–00139) as well as the Swiss State Secretariat for Education and Research for funding. Furthermore we wish to thank PD Dr. H. Sprott for critically reading the manuscript and his fruitful comments as well as Leanne Pobjoy for her help with the manuscript. The study was approved by the ethics committee of the state of Zurich.
- 3.Busch A, Schachter CL, Peloso PM, Bombardier C (2002) Exercise for treating fibromyalgia syndrome. Cochrane Database Syst Rev (3):CD003786Google Scholar
- 8.Fischer AA (1990) Pressure Dolorimetry for differential diagnosis of pain in rheumatological practice. In: Müller W (ed) Generalisierte Tendomyopathie (Fibromyalgie). Steinkopff Verlag. Darmstadt, pp 87–94Google Scholar
- 15.Lautenschläger J (1990) Die Erfassung der Druckpunkte bei generalisierter Tendomyopathie. In: Müller W (ed) Generalisierte Tendomyopathie (Fibromyalgie). Steinkopff Verlag, Darmstadt pp 95–104Google Scholar
- 16.Lautenschläger J, Brückle W, Müller W (1990) Untersuchungen über druckschmerzhafte Punkte bei Patienten mit generalisierter Tendomyopathie. In: Müller W (ed) Generalisierte Tendomyopathie (Fibromyalgie). Steinkopff Verlag, Darmstadt, pp 105–114Google Scholar
- 21.National Research Council, T.I.o.M (2001) Musculoskeletal disorders and the workplace: Low back and upper extremities. National Academy Press, Washington, DCGoogle Scholar
- 29.Wolfe F, Smythe HA, Yunus MB, Bennett RM, Bombardier C, Goldenberg DL, Tugwell P, Campbell SM, Abeles M, Clark P (1990) The American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia. Report of the Multicenter Criteria Committee. Arthritis Rheum 33(2):160–172PubMedCrossRefGoogle Scholar