by Mcleod Ian
SAFETY TIP
When performing this exercise on a pool deck, wear protective gloves to avoid unnecessary trauma to the hands.
CHAPTER 5
ABDOMEN
To move your body efficiently through the water, a coordinated movement of the arms and legs must occur. The key to this coordinated movement is a strong core, of which the muscles of the abdominal wall are a primary component. Besides helping to link the movement of the upper and lower body, the abdominal muscles assist with the body-rolling movements that take place during freestyle and backstroke and are responsible for the undulating movements of the torso that take place during butterfly, breaststroke, and underwater dolphin kicking.
The abdominal wall is composed of four paired muscles that extend from the rib cage to the pelvis. The muscles can be divided into two groups—a single anterior group and two lateral groups that mirror each other. The anterior group contains only one paired muscle, the rectus abdominis, which is divided into a right and left half by the midline of the body. The two lateral groups each contain a side of the remaining three paired muscles—the external oblique, internal oblique, and transversus abdominis (figure 5.1). In human motion and athletics, the abdominal muscles serve two primary functions: (1) movement, specifically forward trunk flexion (curling the trunk forward), lateral trunk flexion (bending to the side), and trunk rotation; and (2) stabilization of the low back and trunk. The motions mentioned earlier result from the coordinated activation of multiple muscle groups or the activation of a single muscle group.
Figure 5.1 Abdominal muscles.
The rectus abdominis, popularly known as the six pack, attaches superiorly to the sternum and the surrounding cartilage of ribs 5 through 7. The fibers then run vertically to attach to the middle of the pelvis at the pubic symphysis and pubic crest. The six-pack appearance results because the muscle is divided by and encased in a sheath of tissue called a fascia. The visible line running along the midline of the body dividing the muscle in two halves is known as the linea alba. Contraction of the upper fibers of the rectus abdominis curls the upper trunk downward, whereas contraction of the lower fibers pulls the pelvis upward toward the chest. Combined contraction of both the upper and lower fibers rolls the trunk into a ball.
The muscles of the two lateral groups are arranged into three layers. The external oblique forms the most superficial layer. From its attachment on the external surface of ribs 5 through 12, the fibers run obliquely (diagonally) to attach at the midline of the body along the linea alba and pelvis. If you were to think of your fingers as the fibers of this muscle, the fibers would run in the same direction as your fingers do when you put your hand into the front pocket of a pair of pants. Unilateral (single-sided) contraction of the muscle results in trunk rotation to the opposite side, meaning that contraction of the right external oblique rotates the trunk to the left. Bilateral contraction results in trunk flexion.
The next layer is formed by the internal oblique. The orientation of its fibers is perpendicular to those of the external oblique. This muscle originates from the upper part of the pelvis and from a structure known as the thoracolumbar fascia, which is a broad band of dense connective tissue that attaches to the spine in the upper- and lower-back region. From its posterior attachment, the internal oblique wraps around to the front of the abdomen, inserting at the linea alba and pubis. Unilateral contraction rotates the trunk to the same side, and bilateral contraction leads to trunk flexion. The deepest of the three layers is formed by the transversus abdominis, so named because the muscle fibers run transversely (horizontally) across the abdomen. The transversus abdominis arises from the internal surface of the cartilage of ribs 5 through 12, the upper part of pelvis, and the thoracolumbar fascia. The muscle joins with the internal oblique to attach along the midline of the body at the linea alba and pubis. Contraction of the transversus abdominis does not result in significant trunk motion, but it does join the other muscles of the lateral group to function as a core stabilizer. An analogy that often helps people grasp the core-stabilizing function of the muscles of the lateral group is to think of them as a corset that, when tightened, holds the core in a stabilized position.
Note that other muscles, including the serratus anterior and hip flexors, can be recruited along with the abdominal muscles when many of the exercises in this chapter are performed. The serratus anterior commonly functions as a stabilizer of the scapula, as described in chapter 3, but it is also activated during many of the exercises that target the external and internal obliques. The two primary hip flexors are the rectus femoris and the iliopsoas. As described in chapter 7, these muscles can either flex the hip or flex the lower trunk, depending on whether the lower extremity or trunk is stabilized.
The role of the core abdominal muscles in swimming can be easily broken down according to their roles as trunk flexors, trunk rotators, and trunk stabilizers. Through their ability to flex the trunk, the rectus abdominis, external oblique, and internal oblique all play important roles in the movements that take place during swimming. For example, flexion of the trunk during flip turns is initiated by the upper fibers of the rectus abdominis, sustained by the lower fibers of the rectus abdominis, and helped to completion by both obliques. The trunk flexors are also important contributors to the wavelike, or undulating, body roll that takes place during butterfly, breaststroke, and underwater dolphin kicking. Besides contributing to flexion of the trunk, the obliques are responsible for trunk rotational movements. Strong obliques are vital to enhancing the speed of open turns performed during butterfly and breaststroke. The obliques are active during the body-rolling movements that take place during freestyle and backstroke, functioning to link the movements of the arms with the movements of the hips and legs. As previously mentioned, through their ability to function like a corset, the abdominal muscles are central to stabilizing the trunk. Trunk stability is one of the keys to efficient movement through the water, because it ensures a firm base of support upon which the arms and legs can generate their propulsive forces.
When incorporating abdominal strengthening exercises into the dryland program, you must understand the importance of focusing on correct technique. The focal point of correct technique begins with the conscious recruitment of the abdominal muscles, often referred to as setting, or locking in, the core, as described in the sidebar on page 13 of chapter 2. Setting the core first involves using the abdominal muscles to control the positioning of the hips and low back. This is best done by lying on the back, as pictured in the starting position for the first exercise of this chapter, the hollow hold. In this position, contraction of the abdominal muscles rolls the hips backward, pressing the low back against the floor. Conversely, contraction of the hip flexors rolls the hips forward, causing the low back to arch. After becoming comfortable with rolling the hips forward and backward, attention should be switched to holding the low back and pelvis in a neutral, fixed position. A useful approach to maintaining this neutral position is to visualize all the abdominal muscles as a corset and to focus consciously on contracting the abdominal muscles in this manner. You should perform the process of setting the core at the start of every abdominal exercise, and it should remain the underlying focus while you execute the entire exercise. The most common indicators that you are not setting the core are excessive arching of the low back and, if you are performing an exercise while facing the ground, excessive rounding of the low back and the hips rising toward the ceiling. Either of these compensatory movements is an indication that you are relying on your stronger hip flexors (rectus femoris and iliopsoas) to hold the body position instead of your abdominal musculature.
Hollow Hold
Execution
1. Lie face up on the floor with your arms by your sides, knees bent, and feet on the floor.
2. Tighten the abdominal muscles like a corset to set your core.
3. Lift your shoulders 6 inches (15 cm) off the ground, making sure to keep the low back in a stable and fixed posit
ion.
4. While lifting the shoulders, reach your arms toward the tops of your knees.
5. Hold this position for 60 seconds or until you are unable to keep the low back in the set position.
Muscles Involved
Primary:Rectus abdominis (upper fibers)
Secondary:External oblique, internal oblique, transversus abdominis, serratus anterior
Swimming Focus
This exercise is a good way to learn how to use your abdominal musculature to position the hips for correct technique and to stabilize the low back. In the starting position, you can experiment with contracting and relaxing your abdominal musculature to roll your hips forward and backward. Practicing these movements will help you gain a feel for the positioning of your hips. Gaining this feel will help you detect when you haven fallen out of the proper positioning for the exercise. A partner can monitor your positioning by testing whether he or she can slide a hand under your low back. If your partner can slide a whole hand under your low back, then you have fallen out of the proper position. When you lift your shoulders off the ground, look down your arms and past your knees to increase recruitment of the upper fibers of the rectus abdominis.
Direct benefits include strengthening of the core musculature, which will carry over to a tighter streamline and a reduction in the risk of injury. By targeting the upper fibers of the rectus abdominis, this exercise helps with the initiation of trunk flexion during freestyle and backstroke flip turns.
VARIATION
Hollow Hold With Feet Elevated
Incorporation of the legs will make the exercise significantly more challenging. Again, the key to performing the exercise properly is maintaining contact between the low back and the ground.
Watch TV
Execution
1. Facedown, support your body weight on your toes and forearms.
2. After holding the starting position for 15 seconds, rotate your body so that it is perpendicular to the floor and supported by one arm.
3. Hold this position for 15 seconds and then rotate back to the starting position.
4. Next, rotate your body so that it is again perpendicular to the floor but now facing the opposite direction. Hold for 15 seconds.
Muscles Involved
Primary:Rectus abdominis, external oblique, internal oblique, transversus abdominis
Secondary:Serratus anterior, rectus femoris, gluteus maximus, gluteus medius, biceps femoris, semitendinosus, semimembranosus
Swimming Focus
This exercise is a good way to transition from the hollow hold to a more challenging exercise when the primary focus is engaging the abdominal musculature to stabilize the low back. Again, monitoring the positioning of the hips and low back is important when performing the exercise. In both the starting and the ending position, the body should be held in a straight line from the ankles all the way to the tip of the head. If the hips begin to drop, the swimmer should be cued to focus on tightening the abdominal musculature. Monitoring the position of the head is also important because its position will indirectly affect the positioning of the low back. If the head is out of alignment with the rest of the body, holding proper body positioning will be much more challenging. As you become more proficient at performing the exercise, gradually increase the amount of time that you spend in each position. The goal is to reach 30 to 45 seconds.
This is an excellent all-around exercise for learning how to engage the abdominal muscles in a manner that will carry over to better maintenance of proper hip and low back positioning during all four strokes and when streamlining off starts and turns.
V-Up
Execution
1. Lying face up in a streamlined position, stabilize your core by tightening the abdominal musculature.
2. In unison, bring your arms forward and lift your legs until your hands are able to touch your feet.
3. Slowly reverse the movement, stopping when your hands and feet are just above the ground. Then repeat.
Muscles Involved
Primary:Rectus abdominis (upper and lower fibers)
Secondary:External oblique, internal oblique, transversus abdominis, serratus anterior, rectus femoris, iliopsoas
Swimming Focus
This exercise targets and strengthens the rectus abdominis through a wide range of motion, making it a useful exercise for freestylers or backstroke swimmers who are trying to improve the speed of their flip turns. Emphasizing the tight streamlined position after each repetition will benefit all strokes. When initiating the movement, avoid swinging your hands up and down to generate momentum; this is a form of cheating. The exercise can be made more challenging by holding the streamlined position with the hands and feet just off the ground for 3 to 4 seconds after each repetition.
Flutter Kicks
Execution
1. Lie on the floor with your arms at your sides and tighten the abdominal muscles to set your core.
2. Lift your shoulders 4 inches (10 cm) off the ground and your feet 12 inches (30 cm) off the ground, making sure to keep the low back in a neutral position.
3. Hold this position and flutter kick for 60 seconds or until you are unable to keep the low back stabilized in a neutral position.
Muscles Involved
Primary:Rectus abdominis (lower fibers), rectus femoris
Secondary:External oblique, internal oblique, transversus abdominis, iliopsoas
Swimming Focus
This is a good exercise to transition to after mastering the hollow hold. As with the hollow hold, the main emphasis should be on keeping the low back in a stable and fixed position. If the low back begins to arch, the abdominal musculature is no longer holding the low back in a stable and fixed position and is being overpowered by the hip flexors. Incorporation of the flutter-kicking motion makes this exercise particularly useful to freestyle and backstroke swimmers.
To avoid relying on the hands to hold the upper body in its curled position, perform this exercise by holding your hands 1 inch (2.5 cm) off the ground.
VARIATION
Streamlined Flutter Kicks
A variation is to hold your arms in an overhead streamlined position. This variation increases the difficulty of the exercise and makes it more specific to swimmers. Because of the increased difficulty, be sure to keep your focus on holding the core tight and maintaining the low back in a neutral position.
Physioball Crunch
Execution
1. Begin in a bridge position with the ball positioned in the middle of your back. Your fingers should be touching but not interlocked behind your head.
2. Raise your shoulders toward the ceiling and bring your chest forward in a crunching motion.
3. Slowly lower your shoulders back to the starting position.
Muscles Involved
Primary:Rectus abdominis
Secondary:External oblique, internal oblique, transversus abdominis, rectus femoris
Swimming Focus
Because the movement begins with the back in an extended position, this exercise strengthens the rectus abdominis through a range of motion not targeted by any of the other exercises listed in this chapter. This feature makes it a valuable exercise for both breaststroke and butterfly swimmers because it contributes to the undulating body movements that occur during both of these strokes.
While performing the exercise, keep your fingers loose behind your head and do not pull your head forward with your hands. Additionally, the positioning of your body on the physioball should remain constant during the entire exercise. If your hips roll back, your shoulders will rise and you will lose the isolation of the abdominal muscles. An easy way to prevent this from happening is to focus on keeping the thighs parallel to the ground.
VARIATION
Physioball Crunch With Trunk Rotation
Incorporation of the twisting motion diverts the focus of this exercise from the rectus abdominis to the internal and external obliques. This exercise is useful in linking the movement of th
e arms to the movement of the legs in freestyle and backstroke.
Cable Crunch
Execution
1. Kneel on the ground in front of a pulley machine. With your elbows bent, hold the separate ends of a rope pulley handle behind your head.
2. Holding your hips stationary, bend at the waist and crunch your torso downward.
3. Slowly return to the starting position.
Muscles Involved
Primary:Rectus abdominis
Secondary:Serratus anterior, internal oblique, external oblique, transversus abdominis
Swimming Focus
Use of the pulley machine allows this exercise to be performed with variable resistance. As a result, the focus of the exercise can be shifted from endurance to strength simply by altering the weight and number of repetitions performed. The variable resistance offers an advantage when compared with most of the exercises in this chapter, which depend primarily on body weight. The motion performed during the exercise closely mimics the motion performed during a flip turn, but because of the wide range of motion through which the abdominal muscles are targeted and the variable resistance, this exercise is beneficial across all four strokes.
