Need help with biology homework ?

Question

list the six possible movments of the humerus that can occur at the shoulder joint, and name the prime movers of each movement ?

thanks alot

Answer 1

Humeral Articulation or Shoulder-joint movements:

Movements.—The shoulder-joint is capable of every variety of movement, flexion, extension, abduction, adduction, circumduction, and rotation. The humerus is flexed (drawn forward) by the Pectoralis major, anterior fibers of the Deltoideus, Coracobrachialis, and when the forearm is flexed, by the Biceps brachii; extended (drawn backward) by the Latissimus dorsi, Teres major, posterior fibers of the Deltoideus, and, when the forearm is extended, by the Triceps brachii; it is abducted by the Deltoideus and Supraspinatus; it is adducted by the Subscapularis, Pectoralis major, Latissimus dorsi, and Teres major, and by the weight of the limb; it is rotated outward by the Infraspinatus and Teres minor; and it is rotated inward by the Subscapularis, Latissimus dorsi, Teres major, Pectoralis major, and the anterior fibers of the Deltoideus.

The site listed below goes into great depth about this topic, so refer to the site for more information.

Good luck with your Biology class!

Answer 2

homework is there so that you can learn better. I'm sure that with a little searching, either on the internet or in your textbook/notes, you can find the answer. i'm not being mean, i just think that you might find that actually doing the work leads to better grades and more knowledge.

Answer 3

Abduction, adduction, flexion, extension, internal rotation and external rotation are the movements of the shoulder joint.  Many of these movements are from the rotator cuff muscles, supraspinatus (abduction), infraspinatus and teres minor (external rotation) and subscapularis (internal rotation).  The deltiod muscle is also involved in abduction, flexion and extension of the arm.  Teres major has a role in internal rotation and coracobrachialis in adduction of the arm.  There are many more muscles involved, I recommend looking at the source (below).

NB.  When I say arm I am referring to the humerous.