During back rowing prep 3, which muscles are essential for maintaining arm height?

The correct choice highlights the posterior deltoids and deltoids as essential muscles for maintaining arm height during back rowing prep 3. The posterior deltoids play a critical role in stabilizing the shoulder joint and maintaining proper positioning of the arms. They aid in controlling the movement while ensuring that the arms stay elevated and aligned, which is key during the exercise.

The deltoids, encompassing the entire shoulder muscle group, also contribute to arm elevation and stability. Specifically, they help prevent any excessive forward movement or sagging of the arms, which would compromise the integrity of the exercise.

In contrast, while pectoralis major and biceps are integral muscles in upper body movements, they do not specifically assist in maintaining arm height during this exercise. Similarly, lats and teres major are more involved in pulling actions rather than stabilizing arm position overhead. Quadriceps and calves are lower body muscles and play no role in this upper body focus, further clarifying why they are not relevant in the context of arm height during back rowing prep 3.