The effect of shoulder position on inferior glenohumeral mobilization

Study design: Cross-sectional clinical measurement study.

Introduction: Inferior mobilizations are used to treat patients with shoulder dysfunctions. Common positions recommended for promoting an inferior glide include: (1) an open-packed position (OPP) in which the shoulder is in 55° of abduction, 30° of horizontal adduction, and no rotation; (2) neutral position (NP) of the shoulder; and (3) position of 90° of shoulder abduction (ABDP). Studies comparing the impact of position on inferior mobilization are lacking.

Purpose of the study: To determine the effect of shoulder position on humeral movement and mobilization force during inferior mobilizations.

Methods: Twenty-three subjects were tested bilaterally. Subjects were placed in the OPP, and an ultrasound transducer placed over the superior glenohumeral joint. As inferior mobilization forces were applied through a dynamometer, ultrasound images were taken at rest and during 3 grades of inferior mobilization. This process was repeated in the NP and the ABDP.

Results: In the NP, movements during grade 1, 2, and 3 mobilizations were 1.8, 3.8, and 4.5 mm, respectively. Movements measured in the OPP (1.0, 2.4, and 3.6 mm, respectively) and in the ABDP (1.0, 2.2, and 2.3 mm, respectively) were less. Forces were higher in the NP during grade 1, 2, and 3 mobilizations (51.8, 138.7, and 202.1 N, respectively) than in the OPP (37.2, 91.2, and 139.9 N, respectively) and the ABPD (42.5, 115.3, and 165.5 N, respectively).

Discussion: Mobilization position altered the movement and force during inferior mobilizations.

Conclusions: Shoulder position should be considered when utilizing inferior mobilizations.

Level of evidence: NA.