EXECUTION
Adjust the seat of the Pec-Deck Machine so that when you are in a seated position your arms will be in line with the shoulders or just slightly below. Sit facing away from the machine with your spine against the back support pad and place the forearms against the pads of the vertical resistance pads.
- When you are in position your entire forearm including the elbow should be resting against the pads as you grasp the hand grips.
- Your feet should be flat on the floor about shoulder width apart and the knees flexed about 90 degrees.
- When you are ready, inhale slightly more than usual and hold your breath as you push against the pads with the arms to move them to the front and towards each other.
- In the ending position, push hard and hold for one to two seconds with a strong contraction of the pecs. Then relax the muscles slightly and exhale as you return to the initial position.
- Keep the return movement under control at all times. Return to a position where the elbows are in line with the shoulders or just slightly to the rear. Do not bring the elbows back to an extreme position unless you have the necessary shoulder flexibility and muscle strength in this range.
- As you reach the rear arm position stop and reverse directions to make use of the eccentric muscle tension developed in the return.
TRAINING TIPS
- To execute the exercise most effectively and without injury make sure that you have the correct seat position. If the machine does not have adjustable seats, or if you cannot make the necessary adjustments do not do the exercise.
- Most important in this exercise is to push the upper arms forward when they are in line with the shoulders or slightly below. In this way you can fully target the lower and upper pecs together with the corachobrachialis and anterior deltoid. If you deviate much from the shoulder level position of the arms you will no longer involve both divisions of the pectorals or the corachobrachialis.
- Do not stop and hold the beginning arms-back position, especially if your elbows are in an extreme position behind the body. When the arms are all the way back and you are at rest, the stress placed on the shoulder is extremely high and can cause injury. Once you are in motion, stop the backward motion of the arms before it becomes stressful to the joints and so that you can use the built up return energy in the forward push.
- To ensure safety and a stronger muscle contraction during the pushing phase, be sure that you do not completely relax the muscles when you return to the initial position. There should be muscle tension to control the movement to the rear and to ensure more power to bring the arms forward.
- Inhaling and holding your breath during the exertion phase is very important. When you inhale, the rib cage expands and stabilizes the trunk so that the anterior deltoid, corachobrachialis, pectoralis major, serratus anterior and pectoralis minor muscles all have a firm base upon which to contract. If the trunk is not held firm when the muscles contract, it will result in a weaker contraction and the possibility of injury. The movement may also feel uncoordinated.
- For safety and to ensure a stronger push in a smooth manner be sure to keep the spine against the back support pads.
Major Muscles Involved
In the shoulder joint, the anterior deltoid, anterior portion of the middle deltoid, corachobrachialis and pectoralis major are the key muscles involved. The anterior and front portion of the middle deltoid cover the front and front sides of the shoulders. The deltoid is especially strong when the arms are in line with the shoulders. The corachobrachialis which lies directly beneath the deltoid and the pectoralis major is fully targeted in this exercise. Most of its mass is below the deltoid.
The pectoralis major is a large muscle covering the chest. In this exercise both the upper and lower divisions of the pectoralis major are involved. The only segments that are not strongly involved are the very lowermost and the very uppermost portions. Depending on how you do the exercise you can also emphasize development of the outer pecs if the arms go back sufficiently far or the inner pecs if you get the arms to come close together with a hard press.
In the shoulder girdle the pectoralis minor and the serratus anterior are the major muscles involved. The pectoralis minor is a small muscle located on the upper chest and is covered by the pectoralis major. This serratus anterior lies on the outer surface of the ribs at the sides just below the armpit. It is covered by the scapula at the rear and the pectoralis major in front.
Muscle and Joint Actions
In the shoulder joint there is horizontal adduction also known as horizontal flexion. In this movement the upper arms are moved forward and towards each other while remaining basically in line with the shoulders. Thus the upper arms move from the sides of the body to the front of the body. As this action occurs there is abduction of the scapulae, ie., the serratus anterior and pectoralis minor pull the scapulae away from the spine towards the sides of the ribs. This allows the arms to move fully to the front and together.
Sports Uses
In bodybuilding the pec-deck-flye is a very important exercise for developing the middle portion of the pectoralis major and the anterior deltoid. Thus you can get great chest and anterior shoulder development in this exercise. In powerlifting, the pec-deck-fly is important for improving performance in the bench press. The combination of shoulder joint horizontal adduction and shoulder girdle abduction is very important in all forward reaching and grabbing actions. Thus it plays a role in sports such as gymnastics, especially when working on the rings and in free exercise, in boxing when throwing various punches and especially hooks, in the martial arts in execution of various punches, in side arm throwing in baseball and softball, and in football tackling. The pec-deck-flye is also a great exercise for the racquet sports such as tennis, racquetball, squash and badminton when executing the forehand stroke.