When massaging the hands and arms, which muscles are affected?

The correct choice highlights the muscles that are directly involved in the movements of the hands and arms. When massaging these areas, it primarily affects the pronators, supinators, flexors, and extensors.

Pronators and supinators are responsible for the rotation of the forearm. The flexors are located in the anterior compartment of the forearm and enable the bending of the wrist and fingers, while the extensors are found in the posterior compartment and allow for the straightening of the wrist and fingers. A massage focusing on these muscles can aid in increasing circulation, reducing tension, and enhancing overall flexibility in the hands and arms.

Other options mention muscles that are either unrelated to the primary movements of the hands and arms or are not in the correct anatomical location. For instance, the deltoids and biceps play roles in shoulder and arm movements but are not specifically targeted during a hand and arm massage. The triceps and quadriceps are primarily associated with arm and leg extension, respectively, and the wrist and ankle stabilizers, while important, are also not directly related to the primary musculature involved in hand and arm massage techniques.