All actions, whether activities of daily living or intense athletic movements, must transmit forces from the lower extremities to the upper extremities via the abdominal complex. The abdominals has been commonly called the core and often has been isolated when strengthened. However, in order for the core to function properly and effectively, the fitness professional needs to look beyond the isolated abdominals and consider what factors cause the abdominals to function. When tracing the abdominal action, one will need to look as far down as the foot and as high as the shoulder girdle complex. In reality, the core starts from the floor.
Anatomical Anatomy vs. Functional Anatomy
The anatomical anatomy is the study of the human body and its muscular, neurological, digestive, genitourinary and cardiorespiratory systems. The functional anatomy delves into the anatomical anatomy and also the chain reaction of adjacent systems upon other systems. For purposes pertinent to our discussion, the fitness practitioner needs to consider not only the region of the attachments of the pelvic musculature but also the chain reaction through the gait cycle. The images below demonstrate anatomical anatomy and the close relationship of the abdominals with the hip flexors and the adductor group.
As one can see, the origin of the rectus abdominis is the pubis symphysis and inserts at 5-7 ribs and xiphoid process.
The external oblique originates at the border of the 8 ribs and margin of the serratus anterior. It inserts on the anterior ½ of iliac crest, inguinal ligament and fascia of rectus abdominis.
The internal oblique originates at the upper half inguinal ligament, anterior 2/3 ilium crest, lumbar fascia and inserts at the 8-10 ribs and linea alba of the rectus abdominis.
The transverse abdominis originates at the outer 1/3 inguinal ligament, inner rim iliac crest, lower 6 ribs, lumbar fascia and inserts at the pubic crest and iliopectineal line and aponeurosis of linea alba. It is readily apparent that all four abdominal muscles attach to each other, the ribs and the pelvis. This makes it critical to incorporate motion from the pelvis and thoracic spine to integrate the lower extremities and upper extremities to create functional activity that is tri-plane in nature.
When viewing the adductor longus, brevis and pectineus, all these muscles attach closely to the pubis symphysis, at the pubis ramus.
The actions of all muscles are dramatically more than the isolated, concentric actions that are discussed in most textbooks. Pure muscle functions are tri-plane in nature; react to gravity and ground reaction forces; are eccentrically loaded before concentrically unloaded; and control momentum and inertia. To bring the anatomical anatomy “to life,” the student of function must learn the actions and chain reaction effects of adjacent muscle groups and also the impact muscles a joint level or two levels away has upon the local muscle at hand. When thinking of the actions of muscle and muscle groups, it is important to think of the muscles in the group and categorize their actions into a collective action rather than an isolated function, because no muscle works independently but rather synergistically. Also, when considering their actions, think about the musculature around the particular muscle group and the fascial connections. By doing this, the fitness professional will develop a thought process by which adjacent muscles have an impact upon other nearby muscle.
For example, when analyzing the hamstring action, the fitness professional needs to be aware that the hamstrings can be affected by the adductors because they share a common fascial connection. Tightness of one muscle group can impact the other due to their “neighboring relationship.” Another example is the impact the hip flexors can have upon the abdominals by nature of their close proximity attachments. Therefore, when considering the chain reaction of muscle function, the student of function must learn the fascial connections that exist within the body and distant tightness can affect other muscle groups in a certain movement pattern. To learn a more indepth approach to integrated flexibility, read my article titled Flexibility Highways or view my online course or DVD of the same name. Additionally, a valuable DVD is "3D Flexibility" by Gary Gray.
Abdominal Chain Reaction
When viewing the abdominal group, one can see the arrangement of the fibers in all three planes. By viewing the above photo sequence of the gait cycle and the role the abdominals play, let’s explore the action of the abdominals in walking and concentrate on the left foot swinging forward. The foot lands on the lateral aspect of the calcaneus as gravity and ground reaction forces cause the heel to turn laterally, or more accurately, eversion. Along with gravity, ground and reaction forces the eccentric control of the anterior tibialis, peroneals and the extensors of the toes lower the foot to the ground. As the calcaneus everts, the subtalar joint abducts, the ankle dorsiflexes and tibia internally rotates, thereby creating a tri-planar motion at the ankle. The anatomical structure of the ankle complex makes the ankle, which dorsiflexes and plantar flexes in the sagittal plane, a perfect complement to the subtalar joint, which functions in the frontal and transverse planes. The posterior calf group, especially the posterior tibialis, lengthens to decelerate and control these actions. As the calcaneus everts during pronation of closed chain activities, the midtarsal joints invert, abduct and dorsiflex in relation to the subtalar joint and rear foot to allow proper absorption of forces through the foot. When the tibia moves over the foot, the soleus decelerates tibial motion in the sagittal plane and the gastrocnemius helps control tibial rotation in the transverse plane. The chain reactions that follow are knee flexion and abduction, hip flexion and internal rotation that absorb the forces of the body and gravity. The eccentric tri-plane actions of the calf, quadriceps and hip musculature must load to control these forces before effective action can transpire.
When the left heel strikes the ground, the right foot is in calcaneal inversion, relative plantar flexion and relative external rotation of the leg. This causes the right pelvis to tilt anteriorly (sagittal plane action), which lengthens the abdominals to the front and downward. Simultaneously, the left arm swings back, which causes the left shoulder to move posteriorly as the thoracic spine rotates to the left (transverse plane action). This causes the abdominals to lengthen up and backward. This reaction is dependent upon the foot and ankle to function properly and allow full pre-load to the lower extremity and hip. Additionally, this position eccentrically loads the hip flexors, adductor complex and rectus femoris as these muscle groups, along with the abdominals, decelerate (eccentrically loaded) hip extension and anterior pelvic tilt. Tightness of any of these muscles can alter the pelvic alignment and lead to suboptimal abdominal function. Additionally, if these actions become limited, the abdominals can be affected and not fully load and can often result in shortening of the abdominals and the muscles of the pelvic complex in all three planes of motion. Lack of motion in any of the events above can cause sub-optimal loading of the abdominals and reduction in the transfer of forces from the ground upward.
Chain Reaction of Pelvic Muscle Issues
Considering the above discussion, let us turn to the chain reaction that can occur due to either abdominal or pelvic musculature tightness. Common injuries that are occurring more often among both the athletic and non-athletic populations are the abdominal strain and groin injuries. According to many physicians and sports conditioning specialists, these injuries are affecting hockey players and those actions of explosive movement involving hip abduction and external rotation at an increasing rate. They attribute a primary cause to weakness of the hip adduction strength, which was 18% lower in the injured players than in uninjured players.
When muscles are weakened, they also tighten and have a significant impact upon the pelvic motion. For instance, a tight hip flexor or adductor group can cause the pelvis to rotate anteriorly. If these muscle groups are tightened, they will not become fully eccentrically loaded as they assist to decelerate hip extension and external rotation prior to their unloading phase. If this happens, undoubtedly, other muscles must work harder to maintain the function of the activity at hand. As the pelvis is anteriorly rotated in this case, the chain reaction will lengthen the abdominals due to the forward orientation of the pelvis. When tightness of muscle ensues, this can impact the adjacent muscle group if there is a fascial connection. In this case, the adductor fascial tightness is impacting the abdominal fascial tightness and can develop a secondary abdominal motion deficiency. This can result in a suboptimal loading of the abdominal complex and loss of force production when the spine cannot fully extend and therefore cause the abdominals to eccentrically load. If this repeatedly or forcefully happens, tissue breakdown will ultimately occur.
The questions of WHY, WHAT and/or HOW must be asked when analyzing the injury cycle of these muscles. WHAT has caused the muscles to become tight? WHY did the chain reaction get dysfunctional? It may be improper foot action, lack of motion in the calf group or possibly a problematic shoulder girdle complex. By understanding the chain reaction of the gait cycle, the student of function may get a clearer view of HOW these factors developed.
Traditional Methods of Training May Not Provide Optimal Results
Typically, the adductor group, abdominals and hip flexors are concentrically trained and isolated when conditioning takes place. When performing sudden or explosive movements, these muscle groups require tri-plane loading in order to gain the greatest amount of mechanical advantage for force production. However, these muscle groups are closely related by their fascial connections and require them to be integrated in their function and training. Therefore, integrated movement patterns must be used to train their movements, and these movement patterns must take place from the ground up.
If a person such as an athlete has an active lifestyle, the risk of abdominal strain can increase due to the repetitive use and limited motion the abdominals eventually accrue. Therefore, as part of a preventive training program, functional integrated abdominal training should be included (for more on this, click here). Additionally, integrated flexibility must be part of a comprehensive program for all populations. The rationale for this is to allow adequate motion of the great toe, forefoot, ankle and calf so that their normal functions will impact the normal biomechanics of the hip and torso, thus fully loading the abdominals in three planes of motion.
Effective training of the abdominals does not necessarily require a “separate” exercise alone. Effective abdominal training should incorporate many of the larger movement patterns, often positioning the performer in stances of gaits that mimic the desired action, and should involve a degree of rotation through the pelvis and thoracic spine. Additionally, the movement should include a pre-loading or lengthening phase followed by an unloading or shortening phase. This “pre-load/unload” cycle will create an efficient and forceful reaction that can enhance performance no matter what the activity may be. However, careful attention must be given to ensure the client has adequate range of motion in the foot, ankle, hip, pelvis and thoracic spine to fully allow the abdominals to fire. If limitations are present in these respective regions, they should be stretched in an integrated manner to improved abdominal function and reduced risk of muscle strain and back injury.
Part 2 of this article will describe successful integrated flexibility strategies and integrated movement patterns that recruit the abdominals in three planes of motion and will enhance pelvic girdle and thoracic spine motion to improve quality of movement for all populations.
Through study of true human motion, the fitness professional can add many tools to their exercise toolbox. With this knowledge, program design is only limited by one’s creativity.