The Abdominal, Flexor and Rotational Muscles: The most striking feature of the abdominal muscles is that they do not attach to the bones that make up the joint, which they articulate. However, by moving the bones to which they are attached, the spinal joints are put into action.
The rectus abdominis, a long slender muscle running across the abdominal wall from the pubic bone to the lower ribs, is the main muscle that flexes the spine. It comprises the other layer of the abdominal muscles and is involved mainly in flexion of the spine, i.e., raising the upper body (mainly the shoulders and head) when the pelvic girdle is stationary or raising the pelvis when the upper body is stationary. In some exercises you can find both the pelvis and shoulder girdle in motion at the same time.
Also involved in flexion of the spine are the internal and external obliques. The external obliques run at a diagonal on both sides of the rectus abdominis and constitute the second layer of abdominal muscle. When viewed from the front, the fibers depict a letter “V”. The internal obliques lie directly under the externals and forms the third layer of abdominal muscle. The fibers of the internal oblique run at 90? to the external oblique at the upper end (in the area of the waist) and form an inverted letter “V” when viewed from the front. The muscle fibers change angles as you move toward the hips and run fairly parallel close to the pubic bone.
Because of the diagonal line of pull of the oblique muscles, their main function is rotation of the spine, not flexion. When there is spinal flexion, the internals contract to rotate the shoulders in one direction, while the externals contract to rotate the shoulders in the opposite direction. Thus, the opposing muscle pulls equalize one another and the resultant force flexes the spinal flexion. Thus, the main function of the oblique muscle is rotation of the spine.
The fourth abdominal muscle is the transverse abdominis, which forms the deepest layer of abdominal muscle. This muscle is not involved in movement of the spine and its main functions are forced expiration and stabilization. The forced expiration also brings into play the internal and external obliques.
Range of Motion: In general, you should do abdominal exercises through the full range of motion for full muscle development. This is especially true of the obliques. However, in some instances, for more mass, a shorter ROM is called for. For example, when peaking a muscle, you must work it through a shortened range close to its maximum size. This can be achieved by using more resistance or doing a maximum number of partial repetitions for greater compaction of the muscle. However, if you use a partial range of motion much of the time, you will lose the normal ROM in the joint which can then led to serious problems not only in other abdominal exercises, but also in execution of other exercises for development of the antagonist muscles. For example, shortened upper abdominals, which create a rounded back position, can lead to different pathways in doing shoulder exercises especially overhead exercises. It can also lead to development of a rounded back.
Individuality: Each of you is a unique individual. Because of this, you do not respond in exactly manner to each exercise as someone else may. Each of these differences may play a significant role in your development. For example, each of you is probably at a different level of ability, you have different levels of exercise mastery, different levels of muscular development, different ages, sex, and years of experience.
There are also differences in your physiological makeup, which allow you to do certain movements more effectively than others. For example, if you have limited rotational abilities in the midsection, doing exercises such as the Russian Twist or the reverse trunk twist you will have to use a limited range of motion until you become more flexible. Strengthening the abdominals through a full range in which you start with a slightly hyperextended spine may be difficult for some individuals because of poor erector spinae development or a limited range of motion in spinal hyperextension. Some individuals may not be able to exhibit the same amount of force because their muscle attachments are slightly different or the size of the muscle is different. Keep in mind that even a small difference of approximately 1/16th of an inch difference in muscle insertion can equate to a major difference in the load that you can handle for your muscular development. Extremely tall people who have an exceptionally long rectus abdominis may find it more difficult to develop a six-pack. Because of this, your workout program must be based on your characteristics, abilities and desires. It must be unique to you and only you.
Exercise Difficulty: When doing abdominal exercises, additional weight or resistance is usually not needed. More important is to select exercises that are more difficult. There are many such exercises that you can select from.
Isolation: Although the term isolation is used to a great extent in bodybuilding, it doesn’t tell the whole story. It would be more accurate to state that you wish to emphasize one muscle of a muscle group more than another, because isolating only one muscle is impossible. For instance, you cannot isolate the rectus abdominis, which is the main muscle that gives you the six-pack, since the internal and external obliques are always also involved, although not as strongly. In addition, the hip flexors undergo isometric contraction to stabilize the pelvis in order to provide a strong base for the abdominal muscles to contract (pull) against. Even when doing forced exhalation to strengthen the transverse abdominis, the internal and external obliques come into play and even the rectus abdominis when the resistance is sufficiently great.
The Exercises: 1. The Crunch or Curl-Up (Sit-Up). Lie on your back with your legs bent at the knees and your feet on the floor or on a bench or secured under rollers. Fold your arms across your chest, or for more resistance, hold them lightly along side the head. Inhale slightly more than usual and hold your breath as you raise your head and shoulders off the floor, concentrating on curling the upper trunk as much as possible. If doing the crunch, rise up only as long as the lumbar spine stays in contact with the floor. When doing the curl-up, continue raising the trunk up to about 45? so that some of the lumbar spine comes off the ground. Hold momentarily, then exhale as you return to the initial position under control. In the curl-up, you go through a greater ROM to tax some of the middle in addition to the upper section of the abdominals.
2. Bench Sit-Ups (also known as Yessis Back Machine Sit-Ups, Glute-Ham Sit-Ups or Roman Chair Sit-Ups, but only if you can properly position yourself). Position yourself face up so that the hips are in full support with the feet secured between the rollers or if on a bench with someone holding down the legs. Your legs should be straight and horizontal and your trunk vertical. Place your hands on your chest, inhale slightly more than usual and hold your breath as you slowly lower your trunk until it is slightly below the level of the horizontal. Your head and shoulders should be below the level of your hips, and there shall be slight hyperextension in the lumbar spine. After reaching the bottom position, keep holding your breath and slowly curl back up to the seated position and exhale.
Lower Abdominals: 3. Reverse Sit-Up (Crunch). Lie on your back on an exercise pad or carpeted floor. Keep your arms over your head on the floor and raise your thighs with the knees bent until the legs are vertical or slightly toward the body. Inhale slightly more than usual and then hold your breath as you raise and rotate the pelvis upward and toward your shoulders until the hips are off the floor. Keep your knees bent tightly as you do this so that the action is isolated to the lower abdominals. In the ending position, your knees should be close to your chest. Keep your head and shoulders relaxed throughout the upward movement. Exhale as you return to the initial position. Stop and then repeat. If this variant is too difficult, place the arms alongside your body and push down with the hands to help rotate the pelvis upward toward the chest.
4. Hanging Leg Raises. Grasp a high bar with your hands so that your entire body can hang vertically using a pronated grip to prevent excessive swinging. When you are ready, inhale slightly more than usual and hold your breath as you raise your legs in hip flexion, keeping them bent or straight for more difficulty. Raise your legs until the thighs are horizontal or higher. Exhale as you return to the starting position under control. Relax a moment and then repeat. For greatest difficulty, raise straight legs as high as possible.
The Obliques: 5. Reverse Trunk Twist. Lie face up on the floor with your arms out to the sides and your palms down. Your arms should be perpendicular to your trunk so that your body forms the letter “T”. Raise your legs to a 90? angle to the floor. Keep the legs straight but with a slight bend in the knees and your feet together.
When you are ready, lower your legs to one side while continuing to hold the 90? angle in your hip joints. Touch the floor with the outside of your lower foot keeping your shoulders and arms in full contact with the floor. Then inhale and raise your legs back to the initial position and without stopping over to the opposite side until your feet touch again keeping your shoulders in contact with the floor. Exhale as you lower your legs and inhale as you raise the legs on alternate sides. If you find it difficult to do it with straight legs, bend the knees more and then execute in the same manner.
6. Russian Twist. This exercise can be done on a flat bench with someone holding your legs down or by yourself on a Yessis Back Machine, Glute-Ham or Roman chair, but only if you can position yourself correctly. Position yourself face up with the hips in full support and your feet secured. Lower your trunk to the horizontal position, so that your entire body is parallel to the floor. Raise your arms so they are perpendicular to the trunk and hold a weight in your hands for greater resistance. Rotate your shoulders and arms as a unit to one side until your arms are relatively parallel to the floor and your shoulders are perpendicular to the floor. Rotate back to the initial position and without stopping continue over to the other side until your arms are once again parallel to the floor and your shoulders are perpendicular to the floor and repeat. As you rotate your shoulders to one side, quickly exhale near the bottom position then inhale quickly and hold your breath as you rotate your shoulder-arm unit upward. Repeat on the opposite side. Breathe quickly so that you have maximum trunk stability.
Obliques and Transverse Abdominis: 7. Resistive Breathing. When using a resistive breathing device such as The Breather, you must first adjust the amount of resistance that you will experience for both inhalation and exhalation. When you are ready, inhale against the resistance and then exhale against the resistance expelling as much air as possible. You should feel the muscles contract as you get most of the air out. Repeat for up to one minute and then rest for one minute and repeat for up to 5 or more minutes. Do while in a relaxed position watching TV or some other similar endeavor.
Introduction: There are probably more exercises for the abdominals than for any other body part. In this article are some exercises that emphasize particular sections of the abdominal muscles.
Although the abdominals are basically the same as other muscles, they do not shorten fully from both ends in most flexion exercises mainly because of their length. When there is flexion of the spine with the shoulders in motion, it is basically the upper abdominals that undergo shortening while the lower section remains under tension. When the pelvic girdle is in motion, it is mainly the lower portion that shortens most while the upper portion remains under static contraction. Also, because of the different angles at which the abdominal muscle fibers are located, each muscle has a specific action, but yet can assist another muscle during movement.
In general, all the abdominals are involved in every exercise but emphasis is placed on a particular muscle or muscle section more specific to the action. For example, the rectus abdominis is involved in flexion of the spine with either the trunk or pelvis in motion while the obliques are responsible for rotational movements. The abdominals, erector spinae and the quadratus lumborum are involved in lateral flexion of the spine while the transverse abdominis plays a major role in holding in the abdominal viscera in place because of its deep location and horizontally running fibers and in forced expiration. Thus, you can work on specific exercises to develop specific portions of the abdominals as well as getting total abdominal development.