Abstract
Objective: To examine the association between pressure pain sensitivity (PPS) at sternum and various well established physiological stress measures among opera singers during a performance as a measure for transitional stress, and resting values in out-clinic patients as a measure for persistent stress. Methods: Changes in PPS on the index finger and sternum, middle blood pressure (MAP), heart rate (HR), pressure-rate-product (PRP) and salivary cortisol (SCO) were recorded in 26 opera solo singers during a performance. Resting PPS, HR, MAP, PRP and presence of a noxious withdrawal reflex (NWR) were recorded in 181 out-clinic patients. Results: During opera performance, the PPS on sternum changed concomitantly with MAP (correlation coefficient (r) r=0.42, p<0.005), HR (r=0.55, p<0.001), PRP (r=0.54, p<0.001) and SCO (r=0.26, p=0.066). During rest, a significant correlation was found between PPS on sternum and HR, PRP and presence of noxious withdrawal reflex (all p<0.01). Conclusions: The PPS measurement at sternum was associated with well established physiological stress measures and may represent a simple, objective and reliable measure of physiological stress used by both non-professional and professionals.
Acknowledgements
We thank Joergen Nyboe (died 2006) for his contribution as a discussion partner with respect to design and methodology during the early phase of the present study. Also we wish to thank S.P. Olesen, F. Gyntelberg and P. Bech for comments and suggestions, N.V. Olsen, R. Grønkjær, T. B. Hagn-Meincke, B. Rasmussen for research assistance, G. Sommer for assistance with the manuscript, Arne Haahr Andreasen for statistical analyses, and Saga Trim A/S Copenhagen for providing exercise test bicycles for the study.
Declaration of interest: Dr Soeren Ballegaard is a share holder of the company that supported the study financially and that owns the instruments Ull Meter, which made the pressure pain sensitivity measurements possible. Therefore the statistical analyses were confirmed by a supplementary external unbiased statistician (Arne Haahr Andreasen).