Correlation between Pressure Pain Threshold and Soft Tissue Displacement in Muscle Pain Conditions
Sirikarn Somprasong PhD*, Keerin Mekhora PhD*, Roongtiwa Vachalathiti PhD*, Sopa Pichaiyongwongdee MSc*
Affiliation : * Faculty of Physical Therapy, Mahidol University Nakhon Pathom, Thailand
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.
Keywords : Pressure pain threshold, Muscle tenderness, Muscle measurement, Delayed onset muscle soreness, Myofascial trigger point
