Question: why doesnt the lower trapezius retract the scapula when all...
Why doesn't the lower trapezius retract the scapula when all other muscles with an origin on the spinal column and insertion on the scapula DO retract the scapula?
a. Because it is weak.
b. Because it inserts on the scapular spine instead of the medial border of the scapula
c. Because the line of pull is not sufficiently horizontal.