Assessment of shoulder function and trumpeter posture: Brachial plexus birth injury and control groups
Madison M Lovette, MS, Jaime Bass, CHT and Stephanie A Russo, MD, PhD, Akron Children's Hospital, Akron, OH
Children with brachial plexus birth injuries (BPBI) often demonstrate a â€œtrumpeterâ€� posture when bringing their affected hands to their mouths. It has been speculated that lack of glenohumeral external rotation is a frequent cause of this posture. However, normative values for these joint angles while bringing the hand to the mouth are unknown. This study aimed to establish normative data for the hand to mouth task and compare typically-developing children with children with BPBI.
Materials and Methods
25 typically developing children ages 6-18 years old (average 11.8 years) with no upper extremity injuries were recruited for three-dimensional motion analysis. Additionally, a retrospective review of motion analysis data for 135 children with BPBI ages 2-19 years old (average 8.5 years) was performed. Three-dimensional motion capture was performed while the children held each arm with their hands to their mouths.
Data was analyzed using custom-written software (LabVIEW, National Instruments Corporation, Austin, TX). A multivariate two-way analysis of variance (Î±=0.05) was used to compare the following angles in the hand to mouth position between BPBI affected arms, BPBI unaffected arms, and typically developing childrenâ€™s dominant arms: ST downward rotation, ST internal rotation, GH elevation, GH external rotation, GH cross-body adduction, HT elevation, HT external rotation, and HT cross-body adduction.
The affected limbs showed significant differences (p<0.001) from the unaffected limbs and typical dominant limbs (Figure 1). Significant differences were found predominantly in the ST internal rotation, GH cross-body adduction, HT elevation, and HT cross-body adduction angles between the affected group and two unaffected groups (unaffected limb of participants with BPBI and limbs of typically developing children). A sub analysis showed that children who received no surgery had less external rotation than those who had previous shoulder surgeries.
These findings suggest that lack of GH cross-body adduction may have a more substantial role in the trumpeter posture than previously appreciated, although prior surgery is a potential confounder. Distal joint function including supination and active elbow flexion may be associated with the trumpeter posture, as well, and warrants further investigation. The findings of this study demonstrate similar joint angles in the unaffected limb of children with BPBI and typically-developing children, reinforcing the use of the unaffected limb as a control.
Back to 2024 Abstracts