Core Muscles

Original Editor - Lucinda hampton

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Introduction[edit | edit source]

A great core exercise: Plank

The core is the group of trunk and hip muscles that surround the spine, abdominal viscera and hip. Core muscles are essential for proper load balance within the spine, pelvis, and kinetic chain. They spare the spine from excessive load and are essential for lad transfer between the upper and lower body.

  • Abdominal, gluteal, hip girdle, paraspinal, and other muscles work in concert to provide this needed spinal stability [1].
  • Having a strong, stable core helps us to prevent injuries and allows us to perform at our best.

There is also an upper quadrant core (glenohumeral and scapulothoracic joints) and a lower quadrant core (hip and trunk)[2] This articles refers to core muscles in relation to lower quadrant core muscles. These being:

  1. Core Trunk Muscles : Abdominals; thoracolumbar; lumbar and lateral thoraco-lumbar muscles
  2. Core Hip Muscles: Hip flexors, extensors, abductors, adductors and rotators[2].

A Muscular Box[edit | edit source]

Muscular Box

The core can be described as a muscular box with the abdominals in the front, paraspinals and gluteals in the back, the diaphragm as the roof, and the pelvic floor and hip girdle musculature as the bottom. Within this box are 29 pairs of muscles that help to stabilize the spine, pelvis, and kinetic chain during functional movements. Without these muscles, the spine would become mechanically unstable with compressive forcces less than the weight of the upper body[1]

Stabilisers and Global Movers[edit | edit source]

Cross section abdo mm.

The core muscles can be divided into two groups, stabilisers and global movers. A coordinated contraction of all stabilisers and global movers are needed for optimal spinal stabilization

The stabiliser muscles include:

The global movers/muscles include:

Muscle Types[edit | edit source]

The core muscles are composed of slow-twitch and fast-twitch muscle fibres, with the stabilisers having a large postural component and are slow twitch, the global movers being fast twitch.

  1. Slow-twitch fibers make up primarily the local stabilising muscle system (the deep muscle layer) - Shorter muscles in length, suited for controlling intersegmental motion required in postural and extrinsic loading responses.
  2. Fast-twitch fibers comprise the global muscle system (the superficial muscle layer) - These muscles are long, have large lever arms, produce large amounts of torque and gross movements. [1]

Myofascial Girdle[edit | edit source]

Thoracolumbar Fascia

The thoracolumbar fascia (TLF) and the erector spinae aponeurosis (ESA) play significant roles in the biomechanics of the spine. The core acts through the thoracolumbar fascia (TLF) and the ESA which are a critical part of a myofascial girdle that surrounds the lower portion of the torso. With contraction of the muscular contents, the TLF and ESA also function as a proprioceptor, providing feedback about trunk positioning.[4]

  1. The erector spinae aponeurosis (ESA) is a common aponeurosis that blends with the thoracolumbar fascia, with a proximal attachment on the sacrum and the spinous processes of the lumbar vertebrae, for the three erector spinae muscles, and overlying the inferior portion of the erector spinae muscles.
  2. The TLF is a structural composite built out of aponeurotic and fascial planes that unite together to surround the core muscles and stabilise the lumbosacral spine, serving as a hoop around the trunk.[4][1]

Physiotherapy[edit | edit source]

Core activation example

The core muscles are extremely important because it maintains proper posture and protects the body's inner organs. They also are crucial to most athletic endeavours because almost all athletic movements utilise these muscles to some extent.

Extension Roman chair

Core strengthening has a strong theoretical basis in treatment and prevention of LBP, as well as other musculoskeletal afflictions[1]. Core muscles strengthening involves a great deal more than simply performing a variety of exercises that target the abdominal muscles and back muscles. These muscles are part of the body's core, but it also includes muscles in the pelvic floor, hips and spine[5].

Exercise of the core musculature is more than trunk strengthening. Lack of sufficient coordination in core musculature can lead to decreased efficiency of movement and compensatory patterns, causing strain and overuse injuries. Thus motor relearning of inhibited muscles may be more important than strengthening in patients with LBP and other musculoskeletal injuries. A core exercise program should be done in stages with gradual progression.

Some traditional progressive resistance strengthening of the core muscles may be unsafe to the back. Heavy resistance training of the lumbar extensors is not recommended eg Roman chair exercises or back extensor strengthening machines require at least torso mass for resistance, which is a load that is often injurious to the lumbar spine, traditional sit-ups also may be unsafe because they create excessive compressive forces in the lumbar spine, caution should be used with full spinal flexion or repetitive torsion, as risk of lumbar injury is greatest with these positions[1].

References[edit | edit source]

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Akuthota V, Ferreiro A, Moore T, Fredericson M. Core stability exercise principles. Current sports medicine reports. 2008 Jan 1;7(1):39-44. Available: (accessed 25.1.2022)
  2. 2.0 2.1 Donatelli RA. Sports-Specific Rehabilitation-E-Book. Elsevier Health Sciences; 2006 Oct 11.Available: 25.1.2022)
  3. Core Strengthening
  4. 4.0 4.1 Willard FH, Vleeming A, Schuenke MD, Danneels L, Schleip R. The thoracolumbar fascia: anatomy, function and clinical considerations. Journal of anatomy. 2012 Dec;221(6):507-36.Available: 26.1.2022)
  5. The healthboard What are the core muscles Available: (accessed 26.1.2022)