Intra- and interrater reliability of belt-stabilized hand-held dynamometer in scapular protraction strength tests in individuals with shoulder pain

Abstract

PurposeScapular protraction strength can be evaluated using a hand-held dynamometer (HHD). However, it is necessary to measure the reliability of HHD in individuals with shoulder pain and to minimize the limitations related to the evaluator and the low methodological quality cited in previous studies. This study assessed, with methodological enhancement, the intra- and interrater reliability of belt-stabilized HHD in the assessment of scapular protraction strength in individuals with shoulder pain. MethodFifty individuals with unilateral symptoms of subacromial pain syndrome (20 men, aged 40.5 ± 15.3 years) were evaluated in two sessions using the belt-stabilized HHD for maximum isometric strength of scapular protraction with the individual in the sitting and supine positions. Reliability values were obtained using the intraclass correlation coefficient with the standard error of measurement (SEM and %SEM) and the minimal detectable change (MDC). ResultsThe intra- and interrater HHD reliability were excellent for all measurements ranging from 0.88 to 0.96 (SEM = 2.0–4.0 kg; %SEM 12 to 17; MDC = 6–11 kg). ConclusionBelt-stabilized HHD is reliable for the assessment of scapular protraction strength in individuals with subacromial pain syndrome in both the sitting and supine positions.