The core or trunk is the

axial Axial may refer to: * one of the anatomical directions describing relationships in an animal body * In geometry: :* a geometric term of location :* an axis of rotation * In chemistry, referring to an axial bond * a type of modal frame, in music * ...

(central) part of an organism's body. In common parlance, the term is broadly considered to be synonymous with the torso, but academically it also includes the

head A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may ...

and

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

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. Functional vs other movements Sports-sp ...

s are highly dependent on this part of the body, and lack of core muscular 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

Major muscles included are the pelvic floor muscles, transversus abdominis, multifidus, internal and external obliques, rectus abdominis,

erector spinae The erector spinae ( ) or spinal erectors is a set of muscles that straighten and rotate the back. The spinal erectors work together with the glutes (gluteus maximus, gluteus medius and gluteus minimus) to maintain stable posture standing or sittin ...

(sacrospinalis) especially the longissimus thoracis, and the

diaphragm Diaphragm may refer to: Anatomy * Thoracic diaphragm, a thin sheet of muscle between the thorax and the abdomen * Pelvic diaphragm or pelvic floor, a pelvic structure * Urogenital diaphragm or triangular ligament, a pelvic structure Other * Diap ...

. The lumbar muscles, quadratus Lumborum (deep portion), deep rotators, as well as cervical muscles, rectus capitus anterior and lateralis, longus coli may also be considered members of the core group. Minor core muscles include the

latissimus dorsi The latissimus dorsi () is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline. The word latissimus dorsi (plural: ''latissimi dorsorum'') comes from L ...

gluteus maximus The gluteus maximus is the main extensor muscle of the hip. It is the largest and outermost of the three gluteal muscles and makes up a large part of the shape and appearance of each side of the hips. It is the single largest muscle in the human ...

, 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.). *Continence :Continence is the ability to withhold bowel movements, and urinary stress incontinence (the lack of bladder control due to pelvic floor dysfunction) can result from weak core musculature. *Pregnancy :Core muscles, specifically the transversus abdominis, are used during labor and delivery. *Valsalva maneuver :Core muscles are also involved in the Valsalva maneuver, where the thorax tightens while the breath is held to assist, often involuntarily, in activities such as lifting, pushing, excretion and birthing.

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 Spine or spinal may refer to: Science Biology * Vertebral column, also known as the backbone * Dendritic spine, a small membranous protrusion from a neuron's dendrite * Thorns, spines, and prickles, needle-like structures in plants * Spine (zoolog ...

, ribs, and

pelvis The pelvis (plural pelves or pelvises) is the lower part of the trunk, between the abdomen and the thighs (sometimes also called pelvic region), together with its embedded skeleton (sometimes also called bony pelvis, or pelvic skeleton). The ...

of a person to resist a specific force, whether static or dynamic. Guide to building a strong core
/ref>

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. Medicine Ball Plank

= Example of static core function

= 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 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 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. * Resistance: Gravity * Plane of movement: Coronal (side to side), Sagittal (forward and behind the anatomical position). Human anatomy planes, labeled

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 the 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.