Posted by lae2 on September 28, 2009 at 23:14:56:
In Reply to: Upper Fibers of Trapezius posted by Big D :P on September 28, 2009 at 21:28:06:
: What do we define as the "upper" fibers of trapezius? Every text I look at has the upper fibers inserting onto the lateral clavicle. But in lecture, it was said that they insert onto the acromion and lateral spine of the scapula. True/false questions are also saying the latter. I realize that the acromion and lateral clavicle are right next to each other, so that might account for some discrepancy, but are we simply to ignore the texts?
Ignore the texts? Of course, what good are they if they are wrong. Look at Gray's 42.52. The "middle fibers" are nevertheless superior to the lateral spine and, thus are in a position to mediate upward rotation. The inset from lecture is from Hollinshead 15.36 pg 235. The phrase "upper part" is used. This would include much of the "middle fibers" as described by Gray's. The point is simply in the mechanics. This can be observed in the laboratory with little controversy.