This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper Extremity, Subject name: Anatomy
Retraction of scapula is by: 
Select and explain. 
A. Upper fibres of trapezius, B. Middle fibres of trapezius, C. Lower fibres of trapezius, D. Upper & lower fibres of trapezius
B: Middle fibres of trapezius
Answer: B: Middle fibres of trapezius 
Explanation: Ans. B. Middle fibres of trapeziusThe trapezius is a large paired surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the spine and laterally to the spine of the scapula.The trapezius has three functional parts: The upper fibers elevate the scapulae, the middle fibers retract the scapulae, and the lower fibers depress the scapulae.