Comparison of shoulder internal rotation passive range of motion in various positions in nonathletic persons and the establishment of normative values for the sidelying position.

BACKGROUND: Loss of shoulder internal rotation (IR) range of motion (ROM) is prevalent in overhead athletes, but it can also be seen in nonathletic persons. A paucity of normative data exists, however, for shoulder IR ROM in positions other than supine, especially in nonathletic persons. The aim of this study was to determine shoulder IR ROM differences between the sidelying, semi-sidelying, and supine positions as well as to establish initial normative values for IR ROM for the sidelying and semi-sidelying positions in nonathletic persons. METHODS: IR ROM was measured on 204 nonathletic persons using the sidelying, semi-sidelying, and supine positions. Mean values of IR ROM for each position were calculated. Differences in IR ROM across the 3 positions and side-to-side differences were examined, including the influence of sex and age on IR ROM. RESULTS: Intra-rater and inter-rater reliability for the sidelying position was excellent. The sidelying position had significantly less IR ROM compared with the other positions, and there was a significant side-to-side IR ROM difference, greatest for the sidelying position (6.8°). Women had significantly more IR ROM than men did, with sidelying normative values of 49° and 55° for female dominant and nondominant shoulders, respectively, and 42° and 51° for male dominant and nondominant shoulders, respectively. CONCLUSION: This investigation establishes initial normative IR ROM values for the sidelying position for both shoulders and sexes. Health care providers can begin to examine IR ROM deficits using these normative values for the sidelying position.

TOTAL ARC OF MOTION IN THE SIDELYING POSITION: EVIDENCE FOR A NEW METHOD TO ASSESS GLENOHUMERAL INTERNAL ROTATION DEFICIT IN OVERHEAD ATHLETES.

BACKGROUND: Total arc of motion (TA) measured in a supine position has been utilized as a method to detect the presence of glenohumeral internal rotation deficit (GIRD) in overhead athletes. A component of supine TA is supine internal rotation (IR) range of motion (ROM), which has many variables including the amount and location of manual stabilization. A sidelying position for gathering IR ROM has recently been proposed and, when combined with supine external rotation (ER) ROM, constitutes a new method of quantifying TA. This new sidelying TA method, however, has no normative values for overhead athletes. PURPOSE: The purposes of this study were to develop normative values for sidelying TA in overhead athletes, determine any ROM difference between supine and sidelying TA, and examine side-to-side differences within the two TA methods. A secondary purpose of the study was to examine for any effect of gender or level of competition on the two TA methods. STUDY DESIGN: Cross-sectional study. METHODS: Passive supine IR ROM, supine ER ROM, and sidelying IR ROM were gathered on bilateral shoulders of 176 collegiate and recreational overhead athletes (122 male [21.4 ± 4.7 years, 71.7 ± 2.7 inches, 25.3 ± 2.7 BMI] and 54 female [21.4 ± 5.4 years, 67.6 ± 3.0 inches, 22.5 ± 2.37 BMI]). RESULTS: Sidelying TA mean for the dominant shoulder was 159.6 °±15.0 °; the non-dominant shoulder was 163.3 °±15.3 °. Sidelying TA for both shoulders (p < 0.0001) was 14 ° less than supine TA. Both TA methods exhibited a 4 ° dominant-shoulder deficit (p < 0.0001). For the dominant and non-dominant shoulder, respectively, there was no gender (p = 0.38, 0.54) or level of competition (p = 0.23, 0.39) effect on sidelying TA. CONCLUSION: In overhead athletes, sidelying TA is a viable alternative to supine TA when examining for the presence of GIRD. Gender and level of competition does not significantly affect sidelying TA, so the mean of 160 ° on the dominant shoulder and 163 ° on the non-dominant shoulder can be used by clinicians. LEVEL OF EVIDENCE: Level 3.