This document discusses motor control and postural control. It defines motor control as the study of movement, which arises from the interaction of perception, cognition, individual characteristics, task constraints, and environmental factors. Postural control maintains stability and orientation through steady-state, reactive, and proactive balance. Steady-state balance involves alignment and muscle tone to counteract gravity. Reactive balance uses strategies like ankle/hip adjustments or changing support when perturbed. Proactive balance anticipates forces through sensory information and experience to stabilize movements like lifting objects. Environmental constraints and cognitive loads also influence balance control.
4. • MOVEMENT:
Accomplishing a particular action, arising from the
interaction of multiple process which includes
perception and cognition.
5. Motor control research that focuses only on
processes
INDIVIDUAL
TASK
ENVIRONME
NT
MOTOR CONTROL
6. INDIVIDUAL CONSTRAIN
MOVEMENT
ARISES FROM THE INTERACTION OF MULTIPLE PROCESSES
ACTION
IMPLES
UNDERSTANDING
THE MOTOR
OUTPUT OF THE
NERVOUS
SYSTEM TO THE
BODY’S
EFFECTOR
SYSTEMS OR
MUSCLES
PERCEPTION
SENSORY
PERCEPTUAL
SYSTEMS PROVIDE
INFORMATION
ABOUT THE BODY
AND
ENVIRONMENT,
AND ARE CLEARLY
INTEGRAL TO THE
ABILITY TO ACT
EFFECTIVELY IN
ENVIRONMENT
COGNITION
ATTENTION,
MOTIVATION AND
EMOTIONAL
ASPECTS
8. TASK CONSTRAINTS
• Nature of performing task being performed in parts determine the type
of movement needed.
• Understanding motor control requires an awareness of how tasks
regulate neural mechanisms controlling movement.
STABILITY MOBILITY MANIPULATION
11. POSTURAL CONTROL
• Postural control is the ability to maintain our body in space
achieving both goals of stability and orientation.
• These goals can be achieved through providing postural tasks
challenging stability and orientation.
• This helps in achieving Independence for patients with
postural instability.
12. Framework for Postural
Control
• Balance emerges from the interaction of the
• Individual
• the task
• the environment
• Functional tasks require three types of balance control
• Control
• Steady-state
• Reactive
• Proactive
• Environmental constraints such as
• Type of support surface
• Sensory cues
• Cognitive demands
• Individual variations such as
• Motor
• Sensory
• Cognitive abilities
13.
14. Task Constraints
Activates of daily living require 3 types of balance control :
• Steady-state balance is the ability to control our balance in
fairly predictable and non- changing conditions.
• Reactive balance control is the ability to recover a stable
position following an unexpected perturbation.
• Proactive or anticipatory balance is the ability to activate
muscles in the legs and trunk for balance control in advance of
potentially destabilizing voluntary movements.
15. • Reactive balance control relies on feedback mechanisms; on the
other hand, proactive balance utilizes the feedforward
mechanisms.
• Feedback control refers to postural control that occurs in response
to sensory feedback from an external perturbation by the
postural control system
• Feedforward control refers to anticipatory postural adjustments
that are made ahead of a voluntary movement that is potentially
destabilizing to maintain stability during the movement.
16.
17. • Most functional tasks require all three aspects of balance
control.
• For example, reaching for a heavy object while standing requires
steady-state balance to maintain a stable position before
reaching for the object, anticipatory balance control to prevent
loss of stability during the reach and lift, reactive balance control
if the object is heavier than expected, and lifting it causes us to
lose balance, and after that steady-state balance again after the
completion of the task.
18. Steady-state balance
• Stability required for tasks like sitting or standing is called "static
balance“.
Several factors contribute to our ability to maintain steady-state
stability
• Alignment of the body can minimize the effect of gravitational
forces that tend to pull us off-center.
• Postural tone to counteract the force of gravity the activity of the
antigravity muscles increases during upright standing. Sensory
inputs from the postural control system are critical to postural tone.
• Researchers have found that many muscles in the body are active
during a quiet stance including
19. • the soleus and gastrocnemius, because the line of gravity falls slightly
in front of the knee and ankle.
• the tibialis anterior, when the body sways in the backward direction
• Gluteus Medius and tensor fasciae latae but not the gluteus maximus
• the iliopsoas, which prevents hyperextension of the hips, but not
the hamstrings and quadriceps
• the thoracic erector spinae in the trunk (along with intermittent
activation of the abdominals), because the line of gravity falls in front
of the spinal column.
• Movement strategies are needed to maintain stability even when
standing or sitting quietly. For this we use one of two strategies
during steady-state balance control; the hip strategy and the ankle
strategy.
20. Reactive Balance Control
Movement strategies used to recover stability in response to
brief displacements can be categorized into two categories:
• Fixed support strategies the previously mentioned ankle and
hip strategy
• Change in support strategies the step strategy and the reach
to grasp strategy.
21. Proactive (Anticipatory)
Balance Control
• The Central nervous system (CNS) uses the sensory
information gathered by the sensory systems and the
information from previous experiences to predict the number
of forces and control needed for the task ahead with also the
ability to change and adapt to new information if the task
turned out to be different than expected.
22. • For example when lifting a heavy object it (judging its
heaviness upon its shape) the central nervous system prepares
us with a magnitude of forces that makes us hold that object
higher when we discover that it was lighter than expected,
then we adapt to the new information (reactive) and this
mistake of ours is saved and added to our proactive control for
a better prediction in the future
23. Environmental Constraints
• Changes in support surfaces affect the organization of muscles
and forces needed for balance as we previously mentioned.
• Differences in visual and surface conditions affect the way
sensory information is used for balance control.
• Finally, daily life often requires that we perform multiple tasks,
affecting the way cognitive systems like attention are used for
balance and adding more cognitive load to the task at hand.
24. Postural Alignment And
Weight Distribution
In Standing
• Normal postural alignment is examined by observing skeletal
alignment using a plumb.
• The COM occurs at a point about two thirds of the body height
above the BOS.
• Static posture is examined by positioning the patient with the
normal stance width.
• In sagittal plane alignment, the plumb line is positioned just in
front of the lateral malleolus.
25. • The vertical line of gravity (LOG) fall close to most
joint axes:
• anterior to the ankle and knee joints
• Posterior to the hip joint
• through midline of the trunk
• anterior to the shoulder joint
• through the external auditory meatus
26.
27. • Natural spinal curves tend to be flattened in upright stance
depending on
• the level of postural tone
• lumbar and cervical lordosis
• thoracic or dorsal kyphosis.
• The pelvis is held in neutral position, with no anterior or
posterior tilt.