Shoulder Rotation Function Following the Sup-ER Protocol in Children with Brachial Plexus Injuries

Background: Our group previously developed an upper extremity repositioning (Sup-ER) protocol for brachial plexus birth injuries (BPBIs) that may improve supination and external rotation (ER) at 2 years of age. Questions were raised about the potential for the protocol to cause internal rotation (IR) deficits. The goal of this study was to explore the longer-term outcomes of the Sup-ER protocol and investigate IR/ER function. Methods: This prospective cross-sectional cohort study examined 16 children older than 4 years of age with significant enough BPBI to be treated with the Sup-ER protocol. Total shoulder and elbow function were assessed, including passive and active ranges of motion and strength of IR and ER. Results: Range of motion (ROM) for most active movements was decreased in the affected compared to unaffected arm. Notably, IR passive ROM was similar in the affected (78.7°) and unaffected arm (82.8°). External rotation strength of the affected arm was weaker (42.8 N) compared to the unaffected arm (57.9 N). IR strength had a greater deficit in the affected (43.2 N) arm compared to the unaffected arm (72.2 N), but both ER and IR showed less deficit than described in the literature. Conclusions: Despite differences in ranges of motion between the affected and unaffected arms, ROMs for the affected arm were comparable to the functional limits as reported in the literature. The Sup-ER protocol shows potential to optimize long-term shoulder rotation function in children with BPBI without compromising IR.