Introduction: Injuries to the Ulnar Collateral Ligament of the elbow are a common occurrence in overhead throwing athletes. Clinical assessment of the medial elbow can be assisted using Sonography. Ultrasound imaging can be used to determine the width of the medial joint space. This study will determine whether altering the joint angle in the elbow during various clinical tests has an effect on the width of the medial joint space.
Methods: Ultrasound images of the non-dominant elbow were collected during three clinical tests of medial elbow stability; valgus stress test, weighted valgus test and the milking maneuver. The width of the medial joint space was measured on images collected in unstressed and stressed conditions.
Results: Research found a significant stress main effect (mean difference=0.7mm, p=<0.001) and a significant difference in medial joint space in the stressed condition (3.7±0.1mm) compared to the unstressed condition (2.9±0.1mm). Analysis revealed that the clinical tests main effect was significant (F(58,2)=4.936, p=0.010). Valgus test means were unstressed (3.0±0.5 mm) and stressed (3.8±0.6mm), and the Milking Maneuver was unstressed (2.8±0.6 mm) and stressed (3.6±0.6mm).
Conclusions: The current study provides evidence that changes in the width of the medial elbow during clinical evaluation of the unimpaired elbow can be detected using sonography. By changing the flexion angle of the elbow, and the position of the forearm we saw a decrease in the width of the medial joint space.