Understanding overall shoulder function and health: the value of specific quantitative vs. qualitative shoulder range of motion on patient-reported outcome measures

It is known that, though widely used, shoulder range of motion (ROM) measurements are not standardized and have a high rate of intra- and interobserver differences. Particularly, the inconsistency in quantitative and qualitative measurements and their relationship to patient-reported outcome measures (PROMs) make shoulder health difficult to determine. This was a prospective study of 147 patients who presented with a chief complaint of shoulder pain to the orthopedic sports medicine and shoulder clinic of a single fellowship-trained surgeon. Measured by 1 examiner, quantitative ROM measurements were taken with a goniometer and qualitative ROM measured by the anatomic level that the patient could reach. The following PROMs were used as well: American Shoulder and Elbow Surgeons shoulder score, Single Assessment Numeric Evaluation, Shoulder Pain and Disability Index, Oxford Shoulder Score, Disabilities of the Arm, Shoulder, and Hand questionnaire, 12-Item Short Form Health Survey, and Patient-Reported Outcomes Measurement Information System pain interference short form 6a (PROMIS 6a). Statistical analysis was performed with SPSS using the Pearson correlation and 2-sample t test. The Benjamini-Hochberg correction was used to determine the P value at which statistical significance was reached to correct for multiple comparisons. Qualitative internal rotation (IR) (the hand behind back reach test) and qualitative forward flexion (FF) correlated with all goniometer angle measurements and PROMs (both shoulder and general health scores). These qualitative measures proved to be an appropriate proxy for IR and FF goniometer measurements. Qualitative external rotation (ER) was not a good substitute for quantitative ER measurement. Quantitative ER correlated with all PROMs. As ROM increased when measured by quantitative ER, qualitative IR, and qualitative FF, shoulder and general health PROMs incrementally increased as well. Qualitative IR measurement, the hand-behind-back reach test, is an adequate substitution for IR goniometer angle as well as a strong representation of global shoulder ROM, shoulder health, and general health while factoring in patient age. Qualitative FF measurement is also an appropriate proxy for quantitative FF and represents global shoulder and general health without factoring in age. Quantitative ER, via goniometer angle, is a better assessment of the shoulder than qualitative ER and is a representation of overall shoulder and general health.