Correlation between pressure pain threshold and soft tissue displacement in muscle pain conditions

Abstract

Objective: To determine the correlation between pressure pain threshold (PPT), displacement pain threshold (DPT) and pain visual analog scale (VAS) in patients with delayed onset muscle soreness (DOMS) and myofascial pain syndrome (MPS). Material and Method: PPT and DPT were measured in the same time by modified Algometertm commander. This study used the algometer for measuring PPT (N/cm2), in three groups of subjects, including DOMS (n = 10), MPS (n = 10), and asymptomatic (n = 10). The DPT represented the displacement of the algometer probe on the skin in millimeters, while measuring PPT. The DOMS was induced in the non-dominant biceps brachii muscle. The subjects with active myofascial trigger point (MTrP) at the upper trapezius muscle were recruited into the MPS group. DOMS group rated pain by VAS during elbow movement, while the MPS group rated at resting. Spearman’s rank coefficient of correlation was used for data analysis. Results: The results showed correlation between PPT and DPT in the asymptomatic biceps brachii muscle (rs = 0.77, p = 0.001) and DOMS group (rs = 0.65, p = 0.04). No correlation was found between MPS and the asymptomatic upper trapezius muscle. Conclusion: A correlation was found between PPT and DPT in biceps brachii muscles. This finding suggested that to assess the DOMS, the PPT and DPT accurately are required for identifying pain and tissue softness.