Question

Which of the following muscles is most likely overactive if a client's head protrudes forward during the pushing assessment?

1) Pectoralis major
2) Latissimus dorsi
3) Sternocleidomastoid
4) Trapezius

Answer 1

The sternocleidomastoid is most likely overactive if a client's head protrudes forward during the pushing assessment, as it is responsible for neck flexion and rotation.

Step-by-step explanation:

If a client's head protrudes forward during the pushing assessment, the muscle that is most likely overactive is the sternocleidomastoid. This muscle is responsible for the flexion and rotation of the neck. When both sternocleidomastoids contract, they cause the head to flex forward. In a forward head posture, these muscles become shortened and tight due to being in a constantly contracted state, leading to an overactive condition that contributes to the forward head posture.

The role of motor nerves such as the accessory nerve is also significant in the function of the sternocleidomastoid, as it innervates this muscle, enabling its action on neck movement. Meanwhile, muscles like the pectoralis major and latissimus dorsi play roles in moving the humerus and positioning the pectoral girdle, but are not primarily responsible for the forward movement of the head.