What is the primary indicator of a UCL sprain during a valgus stress test?

The primary indicator of a UCL (ulnar collateral ligament) sprain during a valgus stress test is the combination of pain and laxity. When conducting the test, the examiner applies a valgus force to the elbow, which stresses the UCL. If there is an injury to the ligament, the patient will typically experience pain at the site of the ligament and demonstrate laxity, indicating that the ligament is not providing the necessary stabilization for the joint.

The presence of pain suggests that the ligament is irritated or damaged, while laxity indicates that the ligament might be compromised and unable to support the joint effectively during the stress applied. This combination of symptoms is key to diagnosing a UCL injury and understanding the severity of the sprain, which can lead to appropriate treatment and rehabilitation strategies.

While other symptoms such as weakness, swelling, or decreased range of motion may accompany a UCL injury, they are not primary indicators tested in this specific context. Weakness may arise due to disuse or pain, swelling could be a result of inflammation, and decreased range of motion may occur but does not provide a direct assessment of the ligament's integrity like pain and laxity do during the valgus stress test.