What critical element should the Soldier maintain during the Rower exercise?

During the Rower exercise, it is crucial for the Soldier to maintain a proper form to prevent injury and ensure the effectiveness of the workout. Keeping the low back from being excessively arched is essential because an exaggerated arch can lead to strain on the lower back, potentially resulting in injury. A neutral spine position helps engage the core muscles properly and supports overall body mechanics during the exercise, contributing to better performance and safety.

The other options, while they may pertain to aspects of good form, do not address as directly the importance of spinal alignment in this particular exercise. Therefore, focusing on minimizing arch in the low back is vital for maintaining a safe and effective execution of the Rower movement.