[L3 Anatomy and Physiology] Section 3: Postural and core stability

Question 1

Define core stability

Answer 1

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.

Question 2

Name the four main ligaments of the spine

Answer 2

Anterior longitudinal ligament
Posterior longitudinal ligament
Interspinous ligament
Intertransverse ligament

Question 3

What does the anterior longitudinal ligament connect and what excess movement does it prevent.

Answer 3

This connects each vertebral body together and runs anteriorly along the front of the spine preventing excess extension of the spine.

Question 4

What does the posterior longitudinal ligament connect and what excess movement does it prevent.

Answer 4

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.

Question 5

What does the Interspinous ligament connect and what excess movement does it prevent.

Answer 5

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.

Question 6

What does the Intertransverse ligament connect and what excess movement does it prevent.

Answer 6

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.

Question 7

How much force can the passive structures of the spine withstand, and what does this suggest about the muscular system?

Answer 7

4-5lbs - This suggests that the muscular system is primarily responsible for maintaining core stability and posture.

Question 8

The muscles of the spine can be grouped into three distinct layers. What are they?

Answer 8

Deep, middle, and outer

Question 9

Within the deep layer of the spinal musculature,

what are the two categories of movements of the spine?

Answer 9

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.

Question 10

What are the deep layer muscles also known as, and why?

Answer 10

‘Position sense muscles’ as they help to provide feedback to the central nervous system about small
movements and variations in spinal position

Question 11

What are the three deep muscles of the spine?

Answer 11

Intertransversarii
Interspinalis
Rotatores

Question 12

Where does the Intertransversarii attach and what movement does it assist in?

Answer 12

Attaches between the transverse processes of the spine. They help to bring about lateral flexion and control smaller movements between vertebrae

Question 13

Where does the Interspinalis attach and what movement does it assist in?

Answer 13

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

Question 14

Where do the Rotatores attach and what movement does it assist in?

Answer 14

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.

Question 15

What are the middle layer muscles also known as, and what is its function?

Answer 15

The inner unit - Helps to provide stability and to create intra-abdominal pressure that stabilizes the spine during movement

Question 16

What muscles make up the middle layer (inner unit)?

Answer 16

Middle layer muscles include the:
Transversus abdominis (TVA)
Lumbar multifidus
Diaphragm
Pelvic floor.

Question 17

How do the middle layer muscles work together to form the working foundation from which the arms
and legs can function optimally?

Answer 17

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.

Question 18

Describe the Transversus abdominis (TVA) muscles and it’s functions

Answer 18

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

Question 19

Describe the Lumbar multifidus muscles and it’s functions

Answer 19

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.

Question 20

Describe the Diaphragm muscles functions

Answer 20

• The primary muscle that initiates breathing.
• The diaphragm contracts downwards and helps
create intra-abdominal pressure
• Help stabilise the spine

Question 21

Describe the Pelvic floor muscles and it’s functions

Answer 21

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.

Question 22

What is the outer layer ‘more’ responsible for?

Answer 22

The large movements that are possible at the core, but also stabilises the spine by creating tension across the trunk for external support.

Question 23

Outer unit muscles include?

Answer 23

Rectus abdominis
external obliques
erector spinae
latissimus dorsi
the gluteals
and adductors

Question 24

Too much time in a seated position can affect what relationships of muscles, and lead to reductions in what?

Answer 24

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

Question 25

What is the muscle length-tension relationship?

Answer 25

The relationship between the length of a muscle fiber and the force that the fibre produces at that length.

Question 26

What effect on force does optimal muscle length-tension relationship have?

Answer 26

There will be an optimal overlap of actin and

myosin and the force produced is maximal.

Question 27

Abdominal obesity shifts the centre of gravity where?

Answer 27

Abdominal obesity shifts the centre of gravity forward, which in turn leads to

Question 28

The forward shifting of the centre of gravity due to abdominal obesity leads to an increased chance of what?

Answer 28

An increased chance of postural deviations, such as an excessive lordotic lumbar curve (lumbar lordosis).

Question 29

What are the three major types of stretches?

Answer 29

Static
Dynamic
PNF

Question 30

What are the four types of static stretches?

Answer 30

Static Maintenance
Developmental
Static Passive
Static Active

Question 31

What is a Static Maintenance stretch, and what is the purpose?

Answer 31

The muscle is taken to the end of its normal range
Held without bouncing, normally 15-30 seconds.
Used to maintain the normal length of the muscle. After repeated contractions during exercise, the muscle becomes shorter and thicker.

Question 32

What is a Static Developmental stretch, and what is the purpose??

Answer 32

Involves three stages of progressive stretch.
The limb is moved slightly further each time the muscles relaxes.
Used in flexibility training
Develops the length of the fibres themselves, thereby increasing range of movement at a joint.

Question 33

What is a Static Static Passive stretch, and what is the purpose??

Answer 33

Position is held using some other part of the body or with the assistance of a partner or some other apparatus.
Used progressively to increase range of motion.

Question 34

What is a Static Static Active stretch, and what is the purpose??

Answer 34

Position is held with no assistance other than using the strength of the agonist muscles