[L3 Anatomy and Physiology] Section 3: Postural and core stability Flashcards
Define core stability
The ability of your trunk to support the effort and forces from your arms and legs, so that muscles
and joints can perform in their safest, strongest and
most effective positions.
Name the four main ligaments of the spine
Anterior longitudinal ligament
Posterior longitudinal ligament
Interspinous ligament
Intertransverse ligament
What does the anterior longitudinal ligament connect and what excess movement does it prevent.
This connects each vertebral body together and runs anteriorly along the front of the spine preventing excess extension of the spine.
What does the posterior longitudinal ligament connect and what excess movement does it prevent.
This runs along the back of the spine, underneath the spinous processes, and is also connected to the vertebral bodies of each segment. It prevents excess flexion of the spine.
What does the Interspinous ligament connect and what excess movement does it prevent.
These connect each spinous process to the
one immediately above or below and, together
with the posterior longitudinal ligament, to prevent excess flexion of the spine.
What does the Intertransverse ligament connect and what excess movement does it prevent.
These connect each transverse process to the one immediately above or below. These ligaments run on both the left and right side of the spine and prevent excess lateral flexion.
How much force can the passive structures of the spine withstand, and what does this suggest about the muscular system?
4-5lbs - This suggests that the muscular system is primarily responsible for maintaining core stability and posture.
The muscles of the spine can be grouped into three distinct layers. What are they?
Deep, middle, and outer
Within the deep layer of the spinal musculature,
what are the two categories of movements of the spine?
Physiological Movements - responsible for the large motions of the body and allow many functional tasks, such as bending and lifting
Accessory Movements - Occur within a joint such as
movement at each vertebral segment when bending over.
What are the deep layer muscles also known as, and why?
‘Position sense muscles’ as they help to provide feedback to the central nervous system about small
movements and variations in spinal position
What are the three deep muscles of the spine?
Intertransversarii
Interspinalis
Rotatores
Where does the Intertransversarii attach and what movement does it assist in?
Attaches between the transverse processes of the spine. They help to bring about lateral flexion and control smaller movements between vertebrae
Where does the Interspinalis attach and what movement does it assist in?
Attaches between the spinous processes of the spine and help to bring about extension of the spinal segments while also controlling the smaller movements between vertebrae
Where do the Rotatores attach and what movement does it assist in?
Attaches from the spinous process of one vertebra to the transverse process of the vertebra immediately below.
Help to bring about rotation between spinal segments and help to control the smaller movements between vertebrae.
What are the middle layer muscles also known as, and what is its function?
The inner unit - Helps to provide stability and to create intra-abdominal pressure that stabilizes the spine during movement
What muscles make up the middle layer (inner unit)?
Middle layer muscles include the: Transversus abdominis (TVA) Lumbar multifidus Diaphragm Pelvic floor.
How do the middle layer muscles work together to form the working foundation from which the arms
and legs can function optimally?
The middle layer muscles co-contract to create a non-compressible cylinder where the spine is stabilised.
The cylinder has the diaphragm at the top, the pelvic floor at the bottom, and the transversus abdominis
form the walls; the multifidus ‘zips’ up the cylinder posteriorly.
Describe the Transversus abdominis (TVA) muscles and it’s functions
Wraps around the body, attaching to the lower ribs and
the pelvis.
It functions to increase intra-abdominal pressure to stabilise the spine by:
• Drawing the waist in
• Compressing the abdominal contents
Describe the Lumbar multifidus muscles and it’s functions
Composed of a series of smaller muscles that connect the spinous processes of the spine to the transverse processes two to four vertebrae below.
They help to provide:
• Rotation and extension of the spine
• Hold the lumbar segments in an extended position.
Describe the Diaphragm muscles functions
• The primary muscle that initiates breathing.
• The diaphragm contracts downwards and helps
create intra-abdominal pressure
• Help stabilise the spine
Describe the Pelvic floor muscles and it’s functions
Composed of several small muscles that act like a hammock at the base of the body to hold the organs.
In relation to the core, they:
Contract simultaneously with the diaphragm and other core muscles to create intraabdominal pressure and stabilise the spine.
What is the outer layer ‘more’ responsible for?
The large movements that are possible at the core, but also stabilises the spine by creating tension across the trunk for external support.
Outer unit muscles include?
Rectus abdominis external obliques erector spinae latissimus dorsi the gluteals and adductors
Too much time in a seated position can affect what relationships of muscles, and lead to reductions in what?
Too much time in a seated position can affect the length-tension relationships of muscles and lead to reductions in core muscle activation and a lack of neural drive
