Measurement of Scapular Asymmetry and Assessment of Shoulder Dysfunction Using the Lateral Scapular Slide Test: A Reliability and Validity Study

Abstract

Background and Purpose. The Lateral Scapular Slide Test (LSST) is used to determine scapular position with the arm abducted 0, 45, and 90 degrees in the coronal plane. Assessment of scapular position is based on the derived difference measurement of bilateral scapular distances. The purpose of this study was to assess the reliability of measurements obtained using the LSST and whether they could be used to identify people with and without shoulder impairments. Subjects. Forty-six subjects ranging in age from 18 to 65 years (X̄=30.0, SD=11.1) participated in this study. One group consisted of 20 subjects being treated for shoulder impairments, and one group consisted of 26 subjects without shoulder impairments. Methods. Two measurements in each test position were obtained bilaterally. From the bilateral measurements, we derived the difference measurement. Intraclass correlation coefficients (ICC [1,1]) and the standard error of measurement (SEM) were calculated for intrarater and interrater reliability of the difference in side-to-side measures of scapular distance. Sensitivity and specificity of the LSST for classifying subjects with and without shoulder impairments were also determined. Results. The ICCs for intrarater reliability were .75, .77, and .80 and .52, .66, and .62, respectively, for subjects without and with shoulder impairments in 0, 45, and 90 degrees of abduction. The ICCs for interrater reliability were .67, .43, and .74 and .79, .45, and .57, respectively, for subjects without and with shoulder impairments in 0, 45 and 90 degrees of abduction. The SEMs ranged from 0.57 to 0.86 cm for intrarater reliability and from 0.79 to 1.20 cm for interrater reliability. Using the criterion of greater than 1.0 cm difference, sensitivity and specificity were 35% and 48%, 41% and 54%, and 43% and 56%, respectively, for 0, 45, and 90 degrees of abduction. Sensitivity and specificity based on the criterion of greater than 1.5 cm difference were 28% and 53%, 50% and 58%, and 34% and 52%, respectively, for the 3 scapular positions. Conclusion and Discussion. Our results suggest that measurements of scapular positioning based on the difference in side-to-side scapular distance measures are not reliable. Furthermore, the results suggest that sensitivity and specificity of the LSST measurements are poor and that the LSST should not be used to identify people with and without shoulder dysfunction.

Associação entre discinesia escapular e dor no ombro de praticantes de natação

“…Entre os componentes da amostra com essa disfunção, 80% apresentaram presença de dor no ombro. Kibler et al (2) sugeriram um aumento da assimetria no ombro sintomático; entretanto, Odom et al (10) encontraram valores menores em ombros sintomáticos do que em ombros assintomáticos.…”

A Clinical Method for Identifying Scapular Dyskinesis, Part 1: Reliability

“…Abnormal scapular mechanics are present among some persons with subacromial impingement and shoulder instability, yet a validated, clinically feasible method of identifying scapular dysfunction is lacking. 1,4,7 Clinical measures of scapular position based on side-toside differences of linear measures (from the spine to the medial border of the scapula) have lacked reliability, 8,9 and measures of linear asymmetry in athletes may not indicate dysfunction. 10 Additionally, linear measures taken at static arm positions fail to capture the 3-D motion patterns present during dynamic upper extremity movement, as in overhead occupational activity or sports.…”

Clinical assessment of factors associated with subacromial shoulder impingement: a systematic review

“…Two studies required arbitration as they included not only those with a clear diagnosis of SIS but other shoulder conditions. 30,31 Both articles pertained to scapula measurements. The reviewers decided to include these studies in the review as more than half of the symptomatic participants in each study met the description of SIS.…”

“…The reviewers decided to include these studies in the review as more than half of the symptomatic participants in each study met the description of SIS. 30,31 One study included a control group, a non-operative SIS group and a post-operative SIS group. 20 The post-operative group was not included in this review.…”