Final answer:
The correct position for an athlete's elbows during a plank is directly under the shoulders, which helps engage the scapular muscles and stabilize the shoulder joint.
Step-by-step explanation:
When performing a plank exercise, an athlete should ensure their elbows are placed directly under their shoulders for proper alignment. This position helps in engaging the scapular muscles and stabilizes the shoulder joint. Keeping the elbows apart at shoulder width can provide a stable base and proper form to optimize the exercise effectiveness and reduce the risk of injury. It's important to note that the elbows should not flare out to the sides excessively or tuck in too close together as this can compromise the form and effectiveness of the plank. Additionally, spreading elbows apart can activate the scapular muscles, which assists in proper movement of the shoulder blades during various exercises and everyday actions.