Ultrasonographic humeral retrotorsion comparisons in youth gymnasts

Humeral retrotorsion has been studied in youth baseball but is underexplored in other upper-extremity sports. Gymnasts, who often perform repetitive tumbling and overhead weight bearing, are at risk for shoulder pain and impingement. It is unclear if humeral torsional remodeling contributes to these shoulder conditions. The purpose of this study is to compare humeral retrotorsion in the dominant and nondominant arms of female gymnasts vs. nonupper extremity athletes.

Data were drawn from a prospective upper extremity ultrasound registry including female gymnasts and nonupper extremity female athletes (soccer players) aged 8-14 years with open physes, presenting between March 2021 and July 2023. Exclusion criteria were prior upper extremity surgery and metabolic bone disease. Bilateral humeral torsion was measured by a fellowship-trained physician using validated ultrasound methods. Analyses included chi-square and Mann-Whitney tests.

Forty-five female athletes (31 gymnasts and 14 soccer players) were assessed. Mean age was 10.8 years for gymnasts and 10.9 years for soccer players (P = .755). Most athletes (93.3%) were right-hand dominant. Mean humeral retrotorsion in gymnasts was 76.5° (right) and 75.6° (left), and 67.9° (right) and 70.5° (left) in soccer players, with no significant differences in dominant (P = .263) or nondominant arms (P = .228) between groups.

Youth gymnasts did not exhibit significant humeral retrotorsion differences compared to controls, suggesting shoulder syndromes in gymnasts may relate more to soft tissue adaptations than bony changes.