【實用健康app】7 min Push-Ups – Strong Core|最夯免費app-綠色工廠好玩App

A push-up(or press-up) is a common calisthenics exercise performed in a prone position by raising and lowering the body using the arms. Push-ups exercise the pectoral muscles, triceps, and anterior deltoids, with ancillary benefits to the rest of the deltoids, serratus anterior,coracobrachialis and the midsection as a whole. Push-ups are a basic exercise used in civilian athletic training or physical education and commonly in military physical training.

While the push-up primarily targets the muscles of the chest, arms, and shoulders, support required from other muscles results in a wider range of muscles integrated into the exercise.

The rectus abdominis and transversus abdominis contract continually while performing push-ups to hold the body off the floor and keep the legs and torso aligned. The rectus abdominis spans the front of the abdomen and is the most prominent of the abdominal muscles. The transversus abdominis lies deep within the abdomen, wrapping around the entire abdominal area. Both muscles compress the abdomen, and the rectus abdominis also flexes the spine forward, although it does not execute this function when performing push-ups.

The anterior portion of the deltoid muscle is one of the major shoulder-joint horizontal adductors, moving the upper arms toward the chest during the upward phase of a push-up. It also helps control the speed of movement during the downward phase. The deltoid attaches to parts of the clavicle and scapula, just above the shoulder joint on one end, and to the outside of the humerus bone on the other. Along with horizontal adduction, the anterior deltoid assists with flexion and internal rotation of the humerus within the shoulder socket.

The pectoralis major is another main horizontal adductor of the shoulder joint, so it performs the same functions as the anterior deltoid during a push-up. It also contributes to adduction, extension, flexion and internal rotation ranges of motion. The muscle is divided into clavicular and sternal parts. Both parts attach just outside the head of the humerus and run toward the center of the body. The parts then separate, with the clavicular part attaching to the inner two-thirds of the clavicle, and the sternal part to the front of the sternum and the first six ribs.

While the anterior deltoids and pectoralis major muscles work to horizontally adduct the upper arms during the upward phase of a push-up, the triceps brachii muscles, or triceps for short, are also hard at work extending the elbow joints so the arms can be fully extended. The triceps also control the speed of elbow-joint flexion during the downward phase of the exercise. The closer together the hands are placed during a push-up, the harder the triceps work. The muscle is divided into three heads — the lateral head, long head and medial head. The lateral and medial heads attach to the back of the humerus bone, and the long head attaches just behind the shoulder socket on one end; all three heads combine and attach to the back of the elbow on the other.

In the "full push-up", the back and legs are straight and off the floor. There are several variations besides the common push-up. These include bringing the thumbs and index fingers of both hands together (a "diamond pushup") as well as having the elbows pointed towards the knees. These variations are intended to put greater emphasis on the triceps or shoulders, rather than the chest muscles. When both hands are unbalanced or on uneven surfaces, this exercise works the body core. Raising the feet or hands onto elevated surfaces during the exercise emphasizes the upper (minor) or lower (major) pectorals, respectively. Raising the hands with the aid of push-up bars or a dumbbell allows for greater ROM (range of motion), providing further stress for the muscles. In most push-up variations, a person will be lifting about 65% of his or her body weight.