The reliability and validity of measurements designed to quantify posterior shoulder tightness

Abstract

Background: Posterior shoulder tightness (PST) has been implicated in the etiology of numerous shoulder disorders; thus, reliable and valid methods for quantifying PST are necessary.

Objectives: To systematically review the literature pertaining to the reliability and validity of PST measurements.

Methods: Three investigators independently performed an electronic search using the MEDLINE-PubMed, SPORTDiscus, and CINAHL databases. Inclusion criteria consisted of English studies published in peer-reviewed journals that identified the reliability and/or validity of a PST measurement method as the primary focus.

Results: A total of 2860 articles were initially identified with 11 retained for final review. Two measurement procedures were reported that included supine and side lying horizontal adduction with scapular stabilization. PST was quantified with goniometry, inclinometry, and linear techniques. Intra-rater reliability ranged from intraclass correlation coefficient (ICC) = 0.;40 to 0.;96, whereas inter-rater reliability ranged from ICC = 0.;69 to 0.;91. Reliability among symptomatic and asymptomatic participants was comparable and there appeared to be no advantage of one measurement procedure versus another. A trend of higher reliability for inclinometric measurements was identified. In regard to convergent validity researchers reported correlations of r = 0.;35–0.;88 between the aforementioned measurement techniques and internal rotation (IR).

Conclusion: PST measurement procedures have poor-to-good reliability and demonstrate convergence when compared to IR. An advantage of goniometry and inclinometry lies in their ability to gather ratio data, which may be used for inter-subject comparison unlike linear measurement techniques. No studies investigated PST measurements in the post-operative population suggesting a need for future research.

Keywords:

• Posterior capsule
• Flexibility
• Reliability
• Mobility
• Range of motion

Notes

Conflict of interest Declaration: Author #4 has co-authored 3 of the studies analyzed for this review