Between the scapulae, which muscles must be palpated through to reach the erector spinae fibers?

• A. Trapezius and rhomboids
• B. Deltoid and supraspinatus
• C. Latissimus dorsi and teres major
• D. Pectoralis minor and serratus anterior

Answer: (A)

When palpating the erector spinae fibers between the scapulae, you feel them by pressing through the muscles that sit superficially on the back in that region. The layer directly over the spine there is the trapezius, which covers the upper back and shoulders, and beneath it lie the rhomboids, which lie between the scapulae and the spine. Because the erector spinae fibers run along the spine and lie deep to these two muscles, you must palpate through trapezius and rhomboids to access them. The other options don’t overlay the erector spinae in that area: deltoid and supraspinatus are more involved with the shoulder and sit differently on the scapula, latissimus dorsi and teres major are more lateral/below and don’t cover the between-scapula region in the same way, and pectoralis minor and serratus anterior are anterior chest muscles, not the back layer above the erector spinae.