Which condition does valgus stress commonly lead to?

Valgus stress refers to a force that pushes the knee medially, which can lead to strain or injury of the structures on the inner side of the knee. The medial collateral ligament (MCL) is particularly affected by this type of stress because it is located on the inner part of the knee and serves to stabilize it against such forces. When valgus stress occurs, especially during activities that involve pivoting or cutting movements (common in sports), the MCL is put under significant strain. Over time or with enough force, this can lead to a strain or even a tear of the ligament.

Injuries to the lateral collateral ligament (LCL) and anterior cruciate ligament (ACL) typically occur due to different kinds of stressors; for instance, the LCL is more affected by varus stress (force pushing the knee laterally), and ACL injuries often result from rotational forces rather than direct valgus stress. Similarly, injuries to the medial meniscus can occur with valgus stress, but the primary and direct impact of such stress is most closely associated with the MCL. Hence, the correct response identifies the condition most commonly linked with valgus stress as a strain of the medial collateral ligament.