AFAA Personal Trainer Certification Practice Exam

The muscle group that opposes the anterior medial deltoids is the Latissimus Dorsi. The anterior medial deltoids, primarily responsible for shoulder flexion and abduction, work in conjunction with various other muscles to lift and stabilize the arm. The Latissimus Dorsi, located on the lower back, plays an antagonistic role due to its actions of shoulder extension, adduction, and internal rotation.

When considering opposing muscle actions, it's important to note that agonist and antagonist muscles work in pairs. In this case, when the anterior deltoids engage in flexion or abduction of the shoulder joint, the Latissimus Dorsi must relax to allow for smooth movement, serving as the counteracting force during these specific actions. This relationship underscores the principle of muscle balance and coordination essential for effective and safe movement patterns.

Other options, while they play important roles in shoulder movement, do not directly oppose the function of the anterior medial deltoids in the same way.