Which of the following is an example of an isolated strengthening exercise for the elbow and wrist?

The example of an isolated strengthening exercise for the elbow and wrist is the exercise involving palms-up wrist curls. This exercise specifically targets the forearm flexor muscles, which are responsible for wrist flexion, and isolates the movement at the wrist joint to improve strength without excessively involving other muscle groups or joints.

Isolated strengthening exercises are designed to focus specifically on a particular muscle or muscle group, minimizing the involvement of surrounding muscles. In this case, palms-up wrist curls concentrate on the flexors of the wrist while allowing for the elbow to remain relatively stable, ensuring the targeted muscles are worked effectively.

The other options, while they involve elbow and wrist movements, engage additional muscle groups or are more compound movements. For instance, triceps dips involve the triceps and shoulder muscles, making them a compound exercise rather than isolated. The other choices also incorporate movements that involve more than just the elbow and wrist, failing to solely isolate the targeted muscle group in question.