The deltoids move the upper arm up and away from a neutral position at the side. They each have three different major regions, each with different attachment points around the shoulders. Each of these regions moves the arm in a different direction when flexed.
All three major regions of the deltoids attach to the same point on the humerus. The region most toward the front of the body moves the arm up and toward the collarbone. The middle region moves the arm straight up and forward, as when throwing a ball underhand. The rear region lifts the arm directly out to the side.Learn More
The rotator cuff is a group of muscles and tendons that connects the shoulder blade to the upper arm. It is composed of four muscles and various tendons that surround the shoulder socket.Full Answer >
Strengthening the upper arm, forearm, shoulders and chest muscles allows for a harder punch to be thrown. The back muscles play a part in how hard of a punch is thrown as well.Full Answer >
The deltoid is opposed by the pectoralis major and the latissimus dorsi when the arm is moved away from the body to the side. The deltoid group functions to stabilize the shoulder during rotation, preventing dislocation and allowing safe carrying of heavy objects.Full Answer >
The left and the right sides of the heart are separated by walls of tissue known as septums. There are two septums in the heart. The atrial septum separates the left and the right atria, and the ventricular septum separates the left ventricles from the right ventricles.Full Answer >