Position-related Differences in the Passive Shoulder Rotation Range of Motion

Abstract

[Purpose] To clarify position-related differences in the shoulder rotation range of motion (ROM) by comparing the passive shoulder rotation ROM among a total of 9 different positions, including the 1st and 2nd. [Participants and Methods] The rotation ROMs in the 1st, 2nd, and 3rd positions and those between them and position-related differences in the values were examined, involving 60 shoulders of 60 healthy adults. [Results] The total rotation ROM was the greatest in the position with the shoulder abducted at 60˚, followed by the 2nd position and that with the shoulder horizontally flexed at 30˚, in this order. It was the smallest in the 1st position, followed by the 3rd and that with the shoulder flexed at 60˚. The internal rotation ROM decreased from the 2nd to 3rd position, whereas the external rotation ROM increased from the 1st to 2nd position, and decreased from the 1st position to that with the shoulder flexed at 60˚. [Conclusion] The results of this study may be useful as an index to identify time-course changes in patients’ conditions, as they make it easier to objectively understand how the rotation ROM changes with postural changes.