Exploration of the clinical course and longitudinal correlations in frozen shoulder: The role of autonomic function, central pain processing, and psychological variables. A longitudinal multicenter prospective observational study

Psychometric properties of the Disability of Arm Shoulder and Hand (DASH) in subjects with frozen shoulder: a reliability and validity study

“… The correlation between DASH and NPRS was presumed to be moderate (i.e., r s ≥ 0.30 and < 0.60) because pain (measured as pressure pain threshold) has shown to have a strong to fair connection with disability in subjects with FS [ 7 , 67 ]; The correlation between DASH and SPADI Pain subscale was thought to be strong (i.e., r s ≥ 0.60) because the pain has shown a strong to fair connection with disability in subjects with painful shoulders. This hypothesis is different from the previous hypothesis because, unlike the NRS, the SPADI Pain subscale measures pain from the point of view of disability, a variable that the DASH assesses; The correlation between DASH and SPADI Disability subscale score was expected to be strong (i.e., r s ≥ 0.60) because both assess the impact of pathology on activities and participation and assess similar aspects (i.e., disability); The inverse correlation between DASH and SF-36 MCS was presumed to be strong (i.e., r s ≥ -0.60) because there is evidence about connections between motor function and psychological distress in patients with FS [ 5 ]; The inverse correlation between DASH and SF-36 PCS was presumed to be moderate (r s ≥ -0.30 and < -0.60) because the instruments measure interconnected variables, yet not identical.…”

“…The correlation between DASH and NPRS was presumed to be moderate (i.e., r s ≥ 0.30 and < 0.60) because pain (measured as pressure pain threshold) has shown to have a strong to fair connection with disability in subjects with FS [ 7 , 67 ];…”

“…The evidence in the literature for the “self-limiting” and “3-phase” theory appears to be debatable. At the same time, it is suggested that there is an early improvement in disabilities (with the greatest gain in the early disease process) that slows with time [ 7 ]. Consequently, prolonged limitations in active and passive ROM and functionality can last long, with no evidence for complete recovery without supervised treatment [ 8 ].…”