Relaxing on a Bed of Nails: An Exploratory Study of the Effects on the Autonomic, Cardiovascular, and Respiratory Systems, and Saliva Cortisol.
2011 (English)In: Journal of Alternative and Complementary Medicine, ISSN 1075-5535, E-ISSN 1557-7708, Vol. 17, no 1, 5-12 p.Article in journal (Refereed) Published
Abstract Objectives: This study investigated subjective and physiologic responses of lying on a bed of nails (BN) called the Shakti-mat and of listening to relaxing instructions and music. The BN has 6210 sharp-edge 5-mm plastic nails about 5 mm apart. Design: Thirty-two (32) healthy participants went through four conditions in randomized orders combining BN and relaxing instructions. Results: The subjective pain ratings on the BN increased immediately and reached a peak within 30 seconds. The pain then subsided gradually, indicating a habituation effect. Self-rated relaxation increased over time in all conditions. Systolic and diastolic blood pressures were higher, heart rate was slower, and there was more high-frequency power heart rate variability (HRV), and signs of increasing circulation in the back on the BN. The relaxation instruction especially affected breathing and the HRV-indices standard deviations of normal interbeat intervals and low-frequency power, both known to be responsive to slow breathing. There were no differences in saliva cortisol. Conclusions: Healthy participants habituated to the induced pain on the BN and were able to subjectively relax. When on a BN, signs of both sympathetic and parasympathetic nervous system activity were observed. The pain may hypothetically have triggered a parasympathetic response.
Place, publisher, year, edition, pages
2011. Vol. 17, no 1, 5-12 p.
IdentifiersURN: urn:nbn:se:uu:diva-141020DOI: 10.1089/acm.2010.0135ISI: 000286594500003PubMedID: 21208128OAI: oai:DiVA.org:uu-141020DiVA: diva2:384813