A Novel Ultrasound Assessment Technique of the Ulnar Collateral Ligament to Account for the Valgus Stress Effect of Gravity on the Medial Elbow

Asymptomatic male collegiate baseball players' throwing arm had a significantly greater resting joint space when exposed to gravity stress than the nonthrowing arm in the ABER position, possibly as a result of adaptive UCL laxity. However, the bilateral similarity in varus-stressed measurements suggests it may serve as a better baseline for sUS assessments. Future research incorporating varus stress as a baseline in symptomatic athletes may improve the accuracy and clinical relevance of medial elbow laxity evaluations.