Background: Shoulder horizontal adduction (HA) is performed in many activities of daily living. The limited range of motion (LROM) of HA is affected by the tightness of the posterior deltoid, infraspinatus, teres major, and posterior capsule of glenohumeral joint. The LROM of shoulder HA contributes to excessive scapular abduction. Objects: The aim of this study is to compare the scapular abduction distance and three-dimensional displacement of the scapula during shoulder horizontal adduction between subjects with and without the LROM of shoulder HA. Methods: 24 subjects (12 people in LROM group and 12 people in normal ROM group) participated. Subjects with less than 115° of HA ROM were included in LROM group. Shoulder HA was performed 3 times for measuring scapular abduction distance and three-dimensional displacement of the scapula. Tape measure was used for measuring scapular abduction distance. Scapular abduction distance was normalized by dividing the scapular size. Polhemus Liberty was used for measuring the three-dimensional displacement of the scapula. Results: Normalized scapular abduction distance was significantly greater in LROM group than normal ROM group (p<.001). Three-dimensional displacement of the scapula during shoulder HA was greater in LROM group than normal ROM group (p<.05). Conclusion: LROM group had a greater scapular abduction and three-dimensional displacement of the scapula during shoulder HA compared to normal ROM group.

Stiffness of the posterior deltoid is as a causative factor in the limited range of glenohumeral horizontal adduction and various other shoulder pathologies including shoulder impingement syndrome, frozen shoulder, and humerus anterior glide syndrome. The purpose of this study was to compare the effects of two techniques (soft tissue massage and cross-body stretch) on increasing the range of horizontal adduction. Thirty-two subjects with a or greater difference between the right and left sides in horizontal adduction were selected. Sixteen subjects from each group were allocated randomly. Interventions were applied on six occasions for 2 weeks, and the range of horizontal adduction was measured using an inclinometer at pre-and post-intervention. A analysis of variance (interventiontime) was used to compare the effects of the two techniques. In the soft tissue massage group, the angle of horizontal adduction significantly increased compared with the cross-body stretch group. These findings indicate that the soft tissue massage of the posterior deltoid muscle is a more effective method to increase the flexibility of the glenohumeral horizontal adduction.