Download Development of Central control

Understanding the Development
of Central Axial Control
Robyn Smith
Department of Physiotherapy
UFS
2011
Central or proximal control is often
mistakenly referred to as simply trunk
control
Central Axial Control has three
main components:
• Spine (cervical, lumbar & thoracic areas)
• Shoulder girdle
• Pelvis
Why is the development of central
control so important?
1. Maintenance and
adjustments can be
made against the
forces of gravity
Why is the development of central
control so important?
2. Allows the head to
move
independently from
the trunk
Why is the development of central
control so important?
3. Allows the child to
stabilise one part of
the body whilst
moving another
Why is the development of central
control so important?
4. Allows the limbs to
move independently
from the trunk e.g. lifting
up the arms to play with
a toy
“Balancing act”
• Central control requires a fine balance between flexion and
extension
• provides the backdrop for selective and variable human
movements
• Provides a continually changing point of stability
• Feed-forward – learn from prior experience & practice
• Co-ordinated patterns of movement develop and are adapted for
specific functional activities
Head Control
What is head control?
• Is the ability to move the
head dynamically in relation
to the body
• Ability to orientate the head
in space
• Vision, speech and feeding
ability is largely dependant
on the stability of the head
on the trunk
• Dependant on the balanced
muscle action of the neck
flexors and extensors
• Numerous receptors in the
cervical spine play an
important role in balance and
righting
Head control
Common problems
Essential components
•
Correct cervical alignment is
critical
•
Adequate cervical mobility is
•
Neck extensor muscles play an
important in counterbalancing
the forward weight of the head
•
asymmetry can lead to muscle
imbalances, altered muscle
action e.g. SCM becoming an
extensor and increased neural
tension, elevation of the
shoulders
•
Postural deformities e.g. poking
chin or cervical lordosis
•
Inadequate strength of the neck
extensors may result in the
inability to keep the head
aligned
Ribcage &Thoracic spine
Ribcage essential for:
•
•
•
•
•
the protection of the underlying
organs
has a critical role in respiration
increased AP diameter during
inspiration -role in controlling
the intra-thoracic pressures
The ribs attached to the thoracic
vertebrae posteriorly
The thoracic spine is naturally
less mobile than the cervical
spine
The diaphragm and abdominal
musculature attach to the ribs
Abnormal chest form:
• Flaring ribs and indication
of weak abdominals, ribs are
horizontal and the angle of
the clavicle is abnormal
• Pectus carniatum and
barrel chest caused by
strong adduction of the arms
and tight m. pectoralis
• Pectus excavatum – low
muscle tone
Abnormal chest forms
•
Flaring ribs
• Barrel chest
Abnormal chest forms
• Pectus carniatum
• Pectus excavatum
Postural deformities
• Scoliosis
• Kyphosis
Trunk
Trunk muscles work in 3 ways to
provide stability:
• Concentrically against gravity
• Eccentrically to control movements into
gravity
• Dynamically
The changing contour of the vertebral
column
Contour of the vertebral column child
• Infant has a C-shaped
spine
• Thoracic spine relatively
immobile as a measure to
protect underlying organs
• The spinal curvatures
develop over time due to
muscular activity and the
development of central
control
The abdominal musculature
• Surrounds the entire trunk
• Arranged in layers with no one muscle controlling a single
movement
• Attachments to the ribs, vertebrae and pelvis
• Contract in all movements including extension of the spine
• Similar to a “corset”
• Contract in different combinations during dynamic trunk
stabilisation
• Aids the diaphragm in respiration, ensures an effective cough
• Helps gravity pull the ribs downwards
m. transversus abdominus
• Runs from the lower 6 ribs and
attaches to the linea alba
• Key abdominal stabiliser
• Runs horizontally
• Deepest of the abdominal
muscles
Activated before limb movement
e.g. lifting arms
• ? Role in speech and breathing
m. internal & external obliques
• Key abdominal stabiliser
• Unilaterally important in
trunk rotation
• Importation muscle for
respiration
• Bilaterally flexes the
vertebral column
• Role in the control of the
shoulder girdle stabilising m.
serratus anterior and m.
pectoralis
• Stabilises the pelvis during
gait
m. rectus abdominus
• Runs from the pubic
symphesis and attaches to
the xyphoid and ribs
• Not active in postural control
• Composed mainly of phasic
muscle fibres
• Responsible for trunk flexion
• NB !!! Overactive it inhibits
the action of the abdominal
stabilisers
• Weakness may result in poor
trunk flexion, anterior pelvic
tilt, lumbar lordosis and in
cases of severe weakness
the child may even have
difficulty in lifting the head
m. rectus abdominus
Biomechanical
considerations in the
case of an overactive
m. rectus abdominus
• Approximates the
xiphysternum and the
symphysis pubis
• Posterior pelvic tilt
• Flaring of the lower ribs
• Flexed posture
• Has to use capital
extension and arm
support to lift the head
m. trunk and neck extensors
• Arranged in layers
• Composed of bundle of
muscle fibres only extending
over a limited number of
vertebral segments
• Back extensors include mm.
erector spinae, transverse
spinalis and interspinales
longissimus, m. multifidus is
the main stabiliser
• Capital extensors include the
splenius cervices and capitis
m. trunk and neck extensors
• M. quadratus lumborum aids
in extension and unilateral
lateral flexion
• Thoracic spine has the least
amount of extension
m. trunk and neck extensors
• Junction of the various spinal
areas especially the lumbarthoracic junction is can
become hyper-mobile
• Weakness of back extensors
results in a lumbar and
thoracic kyphosis
• shortening of the lumbar
extensors result in a lumbar
lordosis
Trunk
Common problems relating to trunk musculature:
• Asymmetry e.g. side flexion due to muscle
imbalances, shortening or poor posture
• Postural deformities e.g. kyphosis, lordosis, scoliosis
• Reduced thoracic mobility
• Reduced ROM rotation
• Hipermobility especially at the functional areas, but
also lumbar spine > thoracic spine
• Weak hip abductors and m. quadriceps increase the
load placed on the lumbar spine
Shoulder Girdle
Shoulder girdle
•
•
•
•
Floating system
Many interacting parts
Complex system of control
Acromioclavicular joint is of
biomechanical importance as
it is an important muscle
attachment point
• The shoulder girdle is
attached anteriorly to the
body via the clavicle at the
sternoclavicular joint
• Glenoid fossa is shallow in
comparison to the large head
of the humerus, this allows a
large ROM and a wide variety
of movements
Shoulder girdle
Shoulder girdle
• The structural composition of
the shoulder girdle is such
that it does not provide much
stability.
• The shoulder girdle is
heavily dependent on
balanced muscular activity to
provide stability
• The tendons and ligaments
also add to the stability of
the shoulder
Shoulder girdle
• Rotator cuff, comprised of
mm. supraspinatis,
infraspinatis, subscapularis
and teres minor play an
important role in shoulder
girdle activity
Essential in keeping the
head of the humerus head in
the glenoid fossa during arm
movement
Shoulder girdle
The shoulder girdle
provides:
• Stability for head movements
• Controls the orientation of
the glenoid fossa
• Provides stability and
alignment of the infrahyoid
muscle –which plays an
important role during
swallowing and talking
Scapula stability
• Scapula stability plays an
important role in being able
to dissociate the head from
the trunk
• The dynamic stability
depends on the muscle
activation and motor control
• Tightness can develop at a
very early age
• Fixing patterns also common
• Important to work in weightbearing positions, and
closed chain activities
Shoulder girdle
Common problems:
• Abnormalities in tone e.g. low tone results difficulty stabilizing
the humeral head in the glenoid fossa, scapula winging
• Shoulder girdle elevation
• Adduction of the scapula’s in cases of increased tone with
retraction and extension of the humerus
• Shortening of m. pectoralis and teres minor
Pelvis
Anterior vs. posterior pelvic tilt
Pelvic control
• Normal
development
allows for the
preparation of
pelvic mobility and
muscle strength
Preparing for muscle length by:
Lying in prone and pushing up on
extended arms
• Playing with the feet in supine
• Going from sitting to lying and vice
versa, side sitting
• Lateral weight shifts
Pelvic control
Preparing pelvic mobility e.g.
• Transitions e.g. through half
kneeling, side sitting
• Climbing activities
Preparing for pelvic muscle
control:
• Bridging
• Protective extension when
falling over
• Active abdominals
• Contact foot with the
supporting surface- WB
activities
Pelvic control
•
Important elements of pelvic control
involve the activity of:
•
Constant interplay between
stability and mobility e.g.
•
•
•
M.gluteus maximus
M. gluteus medius
M. quadratus lumborum
•
With activities like coming
up into sitting
Transitions
•
Active abdominal muscles
•
Sufficient length of m.iliopsoas, TFL,
hamstrings and quadratus lumborum
Poor alignment of the body segments
leads to the activation of the incorrect
muscle groups
•
Always a point of stability!
Weight bearing on the lower
limbs
•
•
•
•
Plays an important role in the
development of the depth of the
acetabulum – failure to develop
normally may result in instability
and the risk of dislocation
Contributes towards the
development of the correct
angle between the femur neck
and shaft
Essential to the stimulation of
the growth plates which result in
bone growth
Mineralization of bone and
reducing the risk of osteopenia
and pathological fractures
References
• Aubert, E.J. Motor development in the normal child in Pediatric
Physical Therapy. Tecklin, J.S. (Eds) in Pediatric Physical
Therapy. Lippincott, Williams & Wilkins. Baltimore pp17 -65
• Brown, E. 2009. Central control . In the Evaluation and
Treatment of children with CMD (course notes: unpublished)
• Van der Walt, R. 2009. Development of the chest wall. In the
Evaluation and Treatment of children with CMD (course notes:
unpublished)
• Scholtz, C. 2001. biomechanics of the upper extremity. In NDT
basic course notes: unpublished
• Images courtesy of Google images (2009)