Pressure pain threshold mappings of the infraspinatus muscle in chronic unilateral shoulder pain patients do not reflect generalized hypersensitivity

BORDACHAR, DIEGO; BARBOSA, ALEXANDRE CARVALHO; INTELANGELO, LEONARDO; LASSAGA, IGNACIO; MISTA, CHRISTIAN; MENDOZA, CRISTIAN; BIURRUN MANRESA, JOSÉ A.

Musculoskeletal Science and Practice

Elsevier

Lugar: Amsterdam; Año: 2022 vol. 58

2468-7812

ObjectivesIncreased mechanical sensitivity has been observed on the unaffected side in chronic pain conditions, suggesting generalized or widespread hypersensitivity. However, this cannot be considered as a universal response since this hypersensitivity is inconsistent across muscle pain pathologies. The aim of this study was to assess generalized hypersensitivity in chronic unilateral shoulder pain, using pressure pain threshold (PPT) mappings of the infraspinatus muscle. The proposed evaluation is based on the assessment of PPT on a limited subset of sites, reducing potential habituation or sensitization effects.MethodsTwenty-nine patients with unilateral shoulder pain (USP) and twenty-seven healthy volunteers were recruited. PPT was assessed using a manual pressure algometer. Six sites distributed over the infraspinatus muscle were assessed, and three repetitions were performed at each site. Mappings were derived using two-dimensional interpolation.ResultsLower PPT values were found in the symptomatic side in comparison with the asymptomatic side at all assessment sites (estimated difference: 1.42 ± 0.10 kgf/cm2, p