The reliability, validity, and methodologic quality of measurements used to quantify posterior shoulder tightness: a systematic review of the literature with meta-analysis

Abstract

Posterior shoulder tightness (PST) has been linked to numerous shoulder pathologies in both the general and athletic populations. Several methods for documenting PST have been described in the literature, which may lend to variability in clinical practice and research. The purpose of this study was to perform a systematic review with meta-analysis to investigate the reliability, validity, and methodologic quality of methods used to quantify PST. Relevant studies were assessed for inclusion, and selected studies were identified from the PubMed, Embase, Cochrane, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases. Data were extracted from the selected studies and underwent methodologic quality assessment and meta-analysis. The search resulted in 1006 studies identified, with 18 ultimately retained. Intrarater reliability was reported in 12 studies with a summary intraclass correlation coefficient of 0.93 (95% confidence interval, 0.90-0.95), whereas inter-rater reliability was reported in 6 studies with a summary intraclass correlation coefficient of 0.89 (95% confidence interval, 0.80-0.94). Validity was reported in 10 studies, all using internal rotation as the convergent standard, and was found to be significant in all but 1 study. Current methods used to quantify PST have good reliability but are primarily limited to measures of horizontal adduction of the glenohumeral joint with scapular stabilization. Limitations in using a single measurement technique exist particularly as there may be multiple contributing factors to PST. A more comprehensive approach for quantifying PST is necessary, and suggested components include a cluster of techniques composed of horizontal adduction, internal rotation, and total glenohumeral joint range of motion.