During a dumbbell triceps extension, what action occurs at the elbow joint?

During a dumbbell triceps extension, the primary action that occurs at the elbow joint is extension. This happens when the elbow straightens as the triceps muscle, which is located on the back of the upper arm, contracts. When performing the exercise, the individual begins with the elbow flexed, typically holding a dumbbell above the head or behind the neck. As they push the weight upward, the triceps muscles contract to extend the elbow joint, resulting in a straightened arm.

Understanding this movement is crucial for recognizing how various muscles function during weight training exercises. In this case, the triceps muscle is the key mover responsible for elbow extension, making this choice the correct answer.