Identifying patients with shoulder impingement syndrome who improve with scapular training: a clinical prediction study

Introduction There is a preponderance of evidence that scapular training improves scapular muscle performance and decreases the clinical symptoms related to subacromial impingement syndrome (SAIS). To investigate if pain severity, functional disability, scapular upward rotation angle, and upper trapezius/serratus anterior (UT/SA) isometric strength ratio at baseline assessment can predict a patient’s response to scapular training in cases of SAIS. Methods A clinical predictive study was performed on forty-five patients, suffering from SAIS, the assessment included pain severity, disability assessment, scapular upward rotation, and the UT/SA isometric strength ratio. Measurements were collected before and after a 4-week intervention program of scapular muscle training and strengthening of the serratus anterior muscle. The sensitivity and specificity of interfering with this procedure were utilized to identify items included in the clinical prediction rule (CPR). Results Excellent results were shown by the area under the receiver operating characteristic curve (ROC curve) with a pain severity of 0.93 (sensitivity 0.9, specificity 0.33), functional disability of 0.94 (sensitivity 0.956, specificity 0.156), and UT/SA isometric strength ratio of 0.9 (sensitivity 0.9, specificity 0.33) and poor results with a scapular upward rotation angle of 0.66 (sensitivity 0.62, specificity 0.36) as static positioning of the scapula was believed not to be adequate in assessing prediction values, and with the upward scapular rotation angle recently being highlighted as not affecting symptoms of SAIS. Conclusions This study revealed that shoulder pain, functional disability, and UT/SA isometric strength ratios potentially serve as predictors of the efficacy of a scapular training program in patients who suffer from SAIS.