The sternocleidomastoid performs what isolated functions?
a. concentrically accelerates cervical flexion
b. concentrically accelerates abduction of the arm
c. concentrically accelerates cervical rotation
d. a and c
Answer: d. a and c
The sternocleidomastoid concentrically accelerates cervical flexion (a) and rotation (c). Though all muscles are interconnected and interoperable with one another ,this muscle has no direct impact on the movement of the arm.