Skier's Thumb is associated with laxity or instability of which structure?

Skier's Thumb is primarily associated with laxity or instability of the Ulnar Collateral Ligament (UCL) of the thumb. This condition typically results from an injury that occurs when the thumb is subjected to a force that pulls it away from the index finger, commonly seen in skiing accidents when a skier falls while holding onto the ski pole. The UCL is crucial for stabilizing the metacarpophalangeal joint of the thumb, particularly during pinch and grasp actions.

When the UCL is injured or torn, it can lead to instability at the joint, which can impair function and lead to pain. Thus, understanding the role of the UCL in thumb mechanics is essential for recognizing the implications of Skier's Thumb.

Other options do not directly relate to this specific injury. The Abductor Pollicus Longus is a muscle that helps with thumb movement but does not provide joint stability. The Median Nerve is involved in sensation and motor function for the hand but is not the structure affected by Skier's Thumb. The cervical spine is located in the neck and is unrelated to the mechanics of the thumb, focusing instead on the upper extremities.