Paraspinal Skin Temperature Patterns: An Inter- and Intraexaminer Reliability Study

Edward F. Owens, Jr., M.S., D.C., Director of Research
John F. Hart, D.C., Associate Professor
Joseph J. Donofrio, D.C., Assistant Professor
Jason Haralambous, D.C.
Eric Mierzejewski, D.C.


Background: Paraspinal thermography is used by chiropractors as an aid in assessing patients for the presence of vertebral subluxation. Only a few reliability studies have been carried out, with mixed results. Digital infrared scanning equipment is now available with location tracking that may enhance reproducibility. Digitized scans enable a computer-aided interpretation of thermographic patterns.

Objective: Assess the ability of examiners to reproduce thermal patterns.

Study Design: Repeated measures with two examiners assessing the same patient on two occasions. Thirty asymptomatic students served as subjects.

Methods: A TyTron C-3000 hand-held thermographic scanner interfaced to an MS-Windows compatible PC was used for all recordings. Each examiner recorded two scans on each patient as quickly as possible. It took an average of 3 minutes to complete all 4 scans. Data were exported to a spreadsheet for initial analysis, then SPSS for calculation of Intraclass Correlation Coefficients (ICC). Since the starting and stopping points of scans were not always the same, care was taken to align scans visually, using well distinguished peaks on the charts as guides. Scans were cropped to remove artifacts that might have occurred at the beginning and end of the scans. Intra-examiner and interexaminer ICCs were calculated. Results: Skin temperatures ranged from 35.4 to 30.0 C over all scans. The average temperature changed little from the first to the last scans, indicating that subjects' overall skin temperature was stable during the scanning procedure. Intra-examiner ICCs range from 0.953-0.984. The left and right channel data show slightly higher congruence than the Delta channel. The interexaminer reliability coefficients ranged from 0.918 - 0.975. Again the Delta channel shows slightly less reliability although the ICCs were quite high for all channels. Conclusion: Intra-examiner and inter-examiner reliability of paraspinal thermal scans using the TyTron C-3000 were found to be very high, with ICC values between 0.918 and 0.984. Changes seen in thermal scans when properly done are most likely due to actual physiological changes rather than equipment error.

Key Indexing Terms: Chiropractic, Skin Temperature, Thermography, Assessment, Vertebral Subluxation.