Validity and Reliability of Measuring Pressure Pain Threshold Using Manual Algometer in Subjects with Trigger Points on Upper Trapezius Muscle

Abstract

This study aimed to examine the validity and reliability of a method used for assessing myofascial trigger point using manual algometer against a digital algometer served as a standard instrument. Thirty subjects with myofascial trigger point on upper trapezius were recruited and randomly assigned to be assessed the PPT by both methods of algometry separated by 15-min of rest period. Each method was repeated 3 times with 2 min rest between repetitions. Results found that both methods had high reliability.  The ICCs of the manual and digital algometries were 0.97 (95% confidence interval 0.95 to 0.99, P < 0.001) and 0.96 (95% confidence interval 0.93 to 0.98, P < 0.001) respectively. The validity of manual algometry presented by Pearson’s correlation coefficient was 0.9 (95% CI of 0.8 to 1.0 and P < 0.001). In conclusion, manual algometry has excellent reliability and high validity. Therefore, it could be used as an alternative method for assessment and follow-up evaluation in physical therapy interventions.