Participants with restricted dominant shoulder internal rotation range of motion demonstrate no side-to-side difference in humeral head translation; and no difference before and after joint mobilization: a pilot study

Abstract

[Purpose] To compare humeral head translation (HHT) during shoulder elevation between dominant and non-dominant shoulders in participants with limited dominant shoulder internal rotation range of motion (ROM). To determine if joint mobilization alters HHT, and if relationships exist between the bicipital forearm angle and HHT. [Participants and Methods] Fifteen (9 female) participants (age 25.7 ± 6.8 years) with a minimum 15-degree dominant shoulder internal rotation ROM deficit compared to the opposite shoulder participated. All participants underwent bicipital forearm angle (BFA) measurements and ultrasound imaging to measure acromiohumeral and posterior glenohumeral distances in 3 positions: Resting, 90 degrees of shoulder flexion, and 60 degrees of shoulder abduction with full external rotation. Ultrasound images were used to calculate HHT. Participants' dominant shoulders underwent posterior glide mobilization, followed immediately by repeated ultrasound images and ROM measures. [Results] There was no dominant to non-dominant shoulder, or before and after mobilization HHT differences. No correlations existed between bicipital forearm angles and HHT or ROM gains after mobilization. [Conclusion] Participants with internal rotation ROM loss demonstrated symmetrical HHT. Joint mobilization increased ROM, but HHT was unchanged. No relationships existed between BFA and HHT.

Keywords: Humeral retroversion; Joint mobilization; Joint translation.

Fig. 1.

Resting, flexed, abducted positions. a. Resting position, b. Flexed position, c. Abducted position.

Fig. 2.

Acromiohumeral and posterior glenohumeral distances. a. Acromiohumeral distance, b. Posterior glenohumeral distance.

Fig. 3.

Posterior glide mobilization.