According to Bodybuildingforyou.com, the upper arm muscles are important parts of any training routines and especially important if you want to look good in a tank top. The biceps and triceps are the major upper arm muscles and run alongside the humerus bone, while ligaments in the elbow and shoulder attach the humerus to the lower arm bones and shoulder girdle area.
According to Bodybuildingforyou.com, the triceps are the largest arm muscles and make up about two-thirds of upper arm mass. The triceps are large, three-headed muscles that stretch along the back of the upper arm and attache to the humerus bone at one end and the scapula at the other. Bodybuildingforyou.com notes that the triceps work in opposition to the biceps and are responsible for straightening the arm and twisting the wrist upward.
The biceps are two-headed muscles that begin under the shoulders and end just below the elbow joint. Bodybuildingforyou.com notes that the biceps are responsible for lifting and curling the arm as well as rotating the wrist downward.
The brachialis muscle is a smaller muscle just below the biceps. Exrx.net notes that the muscle attaches to the humerus and ulna bones and is responsible for flexing the elbow. The muscle is heavily involved in lifts like the hammer curl. The University of Washington Department of Radiology notes that the brachialis muscle is a major flexor of the forearm, helping to flex the forearm in all directions.
The humerus bone of the upper arm connects to the ulna of the lower arm around the elbow joint with the help of two elbow ligaments. According to E Orthopod.com, the medial collateral ligament and the lateral collateral ligament connect the humerus to the ulna and keep it tightly in place. E Orthopod.com also notes that the medial collateral is located on the inside edge of the elbow, while the lateral collateral is located on the outside edge.
The humerus connects to the scapula with the help of three ligaments in the shoulder area. The University of Michigan Medical School notes that these three ligaments are the glenohumeral ligaments. In addition, the mdeical school says that the ligaments -- the inferior, middle and superior glenohumeral ligaments -- also thicken the shoulder joint and add strength to it.