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Core (anatomy)
Encyclopedia
In anatomy, the core refers, in its most general of definitions, to the body minus the legs and arms. Functional movement
s are highly dependent on the core, and lack of core development can result in a predisposition to injury. The major muscles of the core reside in the area of the belly and the mid and lower back (not the shoulders), and peripherally include the hips, the shoulders and the neck.
muscles, transversus abdominis, multifidus, internal and external obliques, rectus abdominis, erector spinae
(sacrospinalis) especially the longissimus thoracis, and the diaphragm. Minor core muscles include the latissimus dorsi, gluteus maximus, and trapezius.
Core muscles are very important in the Valsalva maneuver
, which is when a person's thorax tightens while holding their breath. This normally involuntary action can be induced by linking one's hands in front of the chest while standing, and then pulling against the hands without letting go. The Valsalva maneuver assists in lifting, excretion, pushing, and birthing.
Continence is the ability to withhold bowel movements, and urinary stress incontinence (the lack of bladder control due to pelvic floor
dysfunction can result in weak core musculature).
Women use their core muscles, specifically the transversus abdominis, during labor and delivery.
, and pelvis
of a person to resist a specific force, whether static or dynamic.
An example of static core function is firing a rifle in the prone position. To maintain accuracy, the shooter must be able to transfer their own body weight and the weight of the rifle into the earth. Any attempt of the shooter to create a dynamic motion of the sights (muscle the sights onto the target vs. allowing it the posture to aim) will result in a jerky posture where the sights do not sit still on the target. For the shooter to maintain accuracy, the muscles cannot exert force on the rifle, and the skeleton must be aligned to set the rifle (and therefore the sights) onto the target. The core, while resting on the ground and relatively far away from the rifle, is nevertheless aligning the spine and pelvis to which the shoulder and arms and neck are connected. For these peripheral elements to remain static, and not move unnecessarily, the spine, pelvis, and rib cage must be aligned towards this end. Thus the core muscles provide support of the axial skeleton
(skull, spine, and tailbone) in an alignment where the upper body can provide a steady, solid base for the rifle to remain motionless.
Because of this functional design, during dynamic movement there is more dependence on core musculature than just skeletal rigidity as in a static situation. This is because the purpose of movement is not to resist a static, unchanging resistance, but to resist a force that changes its plane of motion. By incorporating movement, the bones of the body must absorb the resistance in a fluid manner, and thus tendons, ligaments, muscles, and innervation take on different responsibilities. These responsibilities include postural reactions to changes in speed (quickness of a contraction), motion (reaction time of a contraction) and power (amount of resistance resisted in a period of time).
An example of this is walking on a slope. The body must resist gravity while moving in a direction, and balancing itself on uneven ground. This forces the body to align the bones in a way that balances the body while at the same time achieving momentum through pushing against the ground in the opposite direction of the desired movement. Initially, it may seem that the legs are the prime movers of this action, but without balance, the legs will only cause the person to fall over. Therefore, the prime mover of walking is achieving core stability, and then the legs move this stable core by using the leg muscles.
In the case of a slippery slope, a person may have to react and catch themselves to maintain balance. This is a function of how quickly a person's muscles can react to the situation, a measure of their quickness and speed (how fast they react and how quickly they can recruit the necessary muscles). A person who can react quickly but not recruit their muscles quick enough will know they are falling, but not be able to do anything about it. A person who cannot react quickly enough (or appropriately) but can recruit their muscles with quickness, will be jerky and over-react easily. Finally, assuming the subject has reacted in time and with speed, they must have the power to accept their body's weight, since slipping reduced the load on their muscles, however brief. This ability of the muscles to have power, will make sure that the immediate load can be taken by the muscles and they will be able to restore balance and, hopefully, achieve their goal.
Functional movement
Functional movements are movements based on real-world situational biomechanics. They usually involve multi-planar, multi-joint movements which place demand on the body's core musculature and innervation.- Sports-specific :...
s are highly dependent on the core, and lack of core development can result in a predisposition to injury. The major muscles of the core reside in the area of the belly and the mid and lower back (not the shoulders), and peripherally include the hips, the shoulders and the neck.
Anatomy
Major muscles included are the pelvic floorPelvic floor
The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the...
muscles, transversus abdominis, multifidus, internal and external obliques, rectus abdominis, erector spinae
Erector spinae
The Erector spinæ is a muscle group of the back in humans and animals. It is also known as sacrospinalis in older texts. A more modern term is extensor spinae, though this is not in widespread use. The name of the muscle is pronounced e-rec-tor speen-aye, or e-rec-tor spinae-ee.It is really not...
(sacrospinalis) especially the longissimus thoracis, and the diaphragm. Minor core muscles include the latissimus dorsi, gluteus maximus, and trapezius.
Functions of the core
The core is used to stabilize the thorax and the pelvis during dynamic movement and it also provides internal pressure to expel substances (vomit, feces, carbon-laden air, etc.).- Valsalva maneuver
Core muscles are very important in the Valsalva maneuver
Valsalva maneuver
The Valsalva maneuver or Valsalva manoeuvre is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut...
, which is when a person's thorax tightens while holding their breath. This normally involuntary action can be induced by linking one's hands in front of the chest while standing, and then pulling against the hands without letting go. The Valsalva maneuver assists in lifting, excretion, pushing, and birthing.
- Continence
Continence is the ability to withhold bowel movements, and urinary stress incontinence (the lack of bladder control due to pelvic floor
Pelvic floor
The pelvic floor or pelvic diaphragm is composed of muscle fibers of the levator ani, the coccygeus, and associated connective tissue which span the area underneath the pelvis. The pelvic diaphragm is a muscular partition formed by the levatores ani and coccygei, with which may be included the...
dysfunction can result in weak core musculature).
- Pregnancy
Women use their core muscles, specifically the transversus abdominis, during labor and delivery.
Anatomical posture and support
The core is traditionally assumed to originate most full-body functional movement, including most sports. In addition, the core determines to a large part a person's posture. In all, the human anatomy is built to take force upon the bones and direct autonomic force, through various joints, in the desired direction. The core muscles align the spine, ribsHuman rib cage
-See also:*Terms for bones*Terms for anatomical location*Articulation of head of rib-References:* Clinically Oriented Anatomy, 4th ed. Keith L. Moore and Robert F. Dalley. pp. 62–64...
, and pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
of a person to resist a specific force, whether static or dynamic.
Static core function
Static core functionality is the ability of one's core to align the skeleton to resist a force that does not change.Example of static core function
Axial skeleton
The axial skeleton consists of the 80 bones along the central axis of the human body. It is composed of six parts; the human skull, the ossicles of the middle ear, the hyoid bone of the throat, the rib cage, sternum and the vertebral column...
(skull, spine, and tailbone) in an alignment where the upper body can provide a steady, solid base for the rifle to remain motionless.
- Resistance: Gravity
- Plane of movement: Coronal (side to side), Sagittal (forward and behind the anatomical position).
Dynamic core function
The nature of dynamic movement must take into account our skeletal structure (as a lever) in addition to the force of external resistance, and consequently incorporates a vastly different complex of muscles and joints versus a static position.Because of this functional design, during dynamic movement there is more dependence on core musculature than just skeletal rigidity as in a static situation. This is because the purpose of movement is not to resist a static, unchanging resistance, but to resist a force that changes its plane of motion. By incorporating movement, the bones of the body must absorb the resistance in a fluid manner, and thus tendons, ligaments, muscles, and innervation take on different responsibilities. These responsibilities include postural reactions to changes in speed (quickness of a contraction), motion (reaction time of a contraction) and power (amount of resistance resisted in a period of time).
Example of dynamic core function
An example of this is walking on a slope. The body must resist gravity while moving in a direction, and balancing itself on uneven ground. This forces the body to align the bones in a way that balances the body while at the same time achieving momentum through pushing against the ground in the opposite direction of the desired movement. Initially, it may seem that the legs are the prime movers of this action, but without balance, the legs will only cause the person to fall over. Therefore, the prime mover of walking is achieving core stability, and then the legs move this stable core by using the leg muscles.
In the case of a slippery slope, a person may have to react and catch themselves to maintain balance. This is a function of how quickly a person's muscles can react to the situation, a measure of their quickness and speed (how fast they react and how quickly they can recruit the necessary muscles). A person who can react quickly but not recruit their muscles quick enough will know they are falling, but not be able to do anything about it. A person who cannot react quickly enough (or appropriately) but can recruit their muscles with quickness, will be jerky and over-react easily. Finally, assuming the subject has reacted in time and with speed, they must have the power to accept their body's weight, since slipping reduced the load on their muscles, however brief. This ability of the muscles to have power, will make sure that the immediate load can be taken by the muscles and they will be able to restore balance and, hopefully, achieve their goal.
- Resistance: Gravity and body weight
- Planes of movement: Transverse (head to toe), Saggittal (left to right), Coronal (front to back).
External links
- Power point presentation: What is the core? Jackie Williams, MS, LAT, ATC, Athletic Training Education Program Director. Department of Health, Physical Education, Recreation & Dance, College of Education at the University of Idaho.
- A marine in the prone from mburke0184 at webshots.com.