Motor Control Exam 1 - Normal Postural Control

___ is critical to independence in functional tasks

Postural Control

Impaired Postural Control can result in the loss of ___ and increase the risk of ___, restrict participation, and increase mortality/morbidity risk

Loss of Independence; Increase Fall Risk

Postural Control is defined as...

The control of one's body position in space for the dual purpose of Stability and Orientation

The ability to maintain an approrpriate relationship between Body Segments, Body, and Environment for a task is known as...

Postural Orientation

What is the most common posture for functional tasks?

Vertical / Upright

Postural Stability is the ability to control one's ___ in relationship to one's ___

Center of Mass; Base of Support

Center of Mass

A point at center of Total Body Mass

The Vertical Projection of Center of Mass is the...

Center of Gravity

Base of Support

Area of Body in contact with support surface

What two things influence the Orientation and Stability demands of a task?

The Task itself and the surrounding Environment

Neural Components of Postural Control

Motor Processes, Sensory Processes, Higher-Level Cognitive Processes

What are the three types of Balance Control?

Steady-State, Reactive, Anticipatory

The ability to control the COM relative to the BOS in fairly predictable and non-changing conditions is what type of Balance Control?

Steady-State Balance

What Balance Control is the ability to recover a stable position following an Unexpected Perturbation?

Reactive Balance

Anticipatory Balance is the ability to activate muscles in the ___ and ___ in advance of potentially destabilizing voluntary movements

Muscles in the Legs and Trunk

Feedback Control occurs when?

In response to Sensory Feedback from external Perturbation

Anticipatory Postural Adjustments made in advance of Voluntary Movement is known as...

Feedforward Control

What type of Balance is used when an object is heavier than expected and causes you to stumble?

Reactive Balance

What type of Balance is used when working to prevent balance loss during a reach and lift movement?

Anticipatory

Examples of Environmental Constraints of Postural Control

Changes in Support Surfaces, Differences in Visual/Surface conditions, Multiple Tasks occurring simultaneously

True or False; No muscle activation is required once Steady-State Balance is achieved

False - Spinal muscle activation is required to control sway and prevent body from collapsing due to gravity

Force generated by a Muscle to resist being lengthened is known as what?

Muscle Tone

Upright Posture increases activity in ___ Muscles

Anti-Gravity Muscles

Steady-State Balance is affected by what two factors?

Perceptual (sensory input) and Cognitive (fear) Factors

Motor Patterns used for Anteroposterior Stability in the Ankle and Hips are seen during what type of Balance Control?

Reactive Balance Control

Examples of Fixed Movement Strategies in Response to Perturbations or Loss of Balance

Ankle Dorsiflexion (leaning forward on feet), Hip flexion (pushing hips backwards and bending over to prevent falling)

Stepping and Reach + Grasp are known as ___ Strategies to prevent falling

Change in Support Strategies

Functional Coupling of Muscle Groups to act together as a unit are called...

Movement Strategies . Synergies

When experiencing Small Perturbations on a firm support surface, what Joint will be used as part of Reactive Balance?

Ankle Joint; Forward/Backward sway to maintain balance

The Hip Joint is used as part of Reactive Balance during what type of conditions?

Large + Fast Perturbations and/or when the Support Surface is compliant or smaller than one's Base of Support

What Change-in-Support Strategy is used to extend the Base of Support?

Reach to Grasp Strategy

What Change-in-Support Strategy is used to realign the Base of Support under a shifting/falling Center of Mass?

Step Strategy

What type of Perturbations elicit a Change-in-Support Strategy?

Fast + Large Perturbations

___ Strategies provide primary control for Mediolateral Stabilty during Reactive Balance

Hip Strategies

What Hip Muscles are most active during Reactive Mediolateral Stability

Rectus Femoris, TFL

If the feet are unsupported, what muscles provide main stability in a seated position?

Trunk / Abdominal Muscles

True or False; It is more important to train the activation of a single synergy (ie Fixed Hip Strategies) rather than multiple strategies

False

In Anticipatory Balance Control, what system controls the Anticipatory Actions? This is especially critical to ___ (UE/LE) activities

Central Nervous System; Lower-Extremity Activities

Visual Input is mainly associated with what type of Balance Control?

Steady-State Balance

Visual Input during Steady-State Balance provides the position and motion of the head with respect to ___ and a reference for ___

Surrounding Objects; Verticality

How does the Somatosensory System contribute to Steady-State Balance?

Provides CNS with position and motion information with reference to Support Surfaces and relays Proprioceptive information (location of body segments in relation to each other)

In Reactive Balance, does the Vestibular System contribute more or less than the Somatosensory System?

Less

Control of Body Sway during Reactive Balance is primarily attributed to the ___ System

Somatosensory System

How is Visual Information used in Reactive Balance?

To form a map of Environmental Affordances in the event of an unexpected Perturbation

Attentional Resources are...

Information processing resources that are required to complete a task

When two tasks are performed simultaneously causing Attentional Resources to decrease performance in one or both tasks is known as...

Dual-Task Interference