2. Definition of Core Stability sin

2. Definition of Core Stability single-joint segmental stabilisation that allow the
longer, multi-joint muscles to work more efficiently
Core stability is an important component max- to control spine motions.[5] This combination of
imising efficient athletic function. Function is most muscle activations helps create the ‘neutral zone’
often produced by the kinetic chain, the coordinated, control of the spinal segments. In this ‘neutral zone’
sequenced activation of body segments that places the ligaments see minimal tension.[5-8]
the distal segment in the optimum position at the
optimum velocity with the optimum timing to pro- The abdominal muscles consist of the transverse
duce the desired athletic task.[2] The core is impor- abdominus, the internal and external obliques, and
tant to provide local strength and balance and to rectus abdominus. Contracting the transverse abdecrease
back injury. In addition, since the core is dominus increases intra-abdominal pressure and
central to almost all kinetic chains of sports activi- tensions the thoracolumbar fascia. The transverse
ties, control of core strength, balance and motion abdominals have been shown to be critical in
will maximise all kinetic chains of upper and lower stabilisation of the lumbar spine.[9,10] Abdominal
extremity function. muscle contractions help create a rigid cylinder,
There is no single universally accepted definition enhancing stiffness of the lumbar spine.[11] It is
of core stability. A general definition of core stabili- important to note that the rectus abdominus and
ty that will be used in this article is the ability to oblique abdominals are activated in direction-specontrol
the position and motion of the trunk over the cific patterns with respect to limb movements, thus
pelvis and leg to allow optimum production, transfer providing postural support before limb moveand
control of force and motion to the terminal ments.[3,12-14] Contractions that increase intra-absegment
in integrated kinetic chain activities. dominal pressure occur before initiation of large
segment movement of the upper limbs.[15,16] In this
3. Anatomy, Physiology manner, the spine (and core of the body) is stabilised
and Biomechanics before limb movements occur to allow the limbs to
have a stable base for motion and muscle activation.[
17] Clinically, it has been shown that only a very
3.1 Anatomy small increase in activation of the multifidi and
The core acts as an anatomical base for motion of abdominal muscles is required to stiffen the spinal
the distal segments. This can be considered ‘proxi- segments (5% of maximal voluntary contraction for
mal stability for distal mobility’ for throwing, kick- activities of daily living and 10% of maximal voluntary
contraction for rigorous activity).[18] ing or running activities.[2,3] Most of the prime mov-
er muscles for the distal segments (latissimus dorsi, Core stability requires control of trunk motion in
pectoralis major, hamstrings, quadriceps and iliop- all three planes. In order to provide stability in all
soas) attach to the core of the pelvis and spine. Most planes of motions, muscles may be activated in
of the major stabilising muscles for the extremities patterns that are different from their primary func(
upper and lower trapezius, hip rotators and glutei) tions. For example, the quadratus lumborum (QL)
also attach to the core. muscle functions mainly as a stabiliser of frontal
Numerous muscles make up the complex known plane flexion and extension activities. However, the
as core muscles. Some are small, short muscles with QL is attached from the transverse processes of the
small lever arms to span single joints. These are spine and the 12th rib to the iliac crests. This orienactivated
in ‘length dependent’ muscle activation tation allows QL muscle activation that occurs in
patterns.[4] Others span numerous spinal segments association with flexion, extension and lateral bendand
function as prime mover muscles to integrate ing activities to buttress shearing of the spine in the
several joints and produce force. They are activated plane of movement, making it more than just a
frontal plane stabilising muscle.[19] in ‘force dependent’ activation patterns.[4] Coordination
of both activation patterns is required in the The roof of the core muscle structures is the
multi-segmented structure like the spine. The mul- diaphragm. Simultaneous contraction of the diatifidi
are an example of short muscles that provide phragm, the pelvic floor muscles, and the abdominal