PTH 690 - Week 1 Material

What is motor control?

The ability to regulate or direct the mechanisms essential to movement

What are motor skills?

Activities or tasks that require voluntary control over movements of the joints and body segments to achieve a goal

Movement emerges from what three factors?

The individual, the task, and the environment

What is movement?

A specific pattern of motion to accomplish an action goal

What is feedforward control?

The sending of signals in advance of movement to ready a part of the system for incoming sensory feedback or for a future motor command

What are anticipatory postural adjustments?

Feedforward control

What is feedback control?

Response-produced sensory information received during or after the movement and is used to monitor movement output for corrective actions

What are reactive postural adjustments?

Feedback control

Where does proprioceptive and sensory information decussate?

Lower medulla

Where do pain and temperature decussate?

Same segment in the spinal cord

What does the cognitive system provide for motor control?

Establishes the intent/goals; attention, memory, planning, motivation, and emotion

What are discrete movement tasks?

Have a recognizable beginning and end

Examples of discrete movements?

Kicking a ball or moving from sitting to standing or lying down

What are continuous movement tasks?

The end point of the task is not an inherent characteristic of the task but is decided arbitrarily by the performer

Examples of continuous movements?

Walking or running

What are closed movement tasks?

Performed in a relatively fixed or predictable environment

What are open movement tasks?

Require performers to adapt movement strategies to a constantly changing and often unpredictable environment

What are stability tasks?

Performed with a nonmoving base of support

What are mobility tasks?

Require moving the base of support

What are the six core tasks for movement analysis?

Sitting, sit to stand, standing, walking, step up/down, and reach/grasp/manipulate

What are the three things to look out for with movement analysis?

Ability to maintain position; moving within a position; and moving between positions

What are regulatory conditions?

Features of the environmental context to which movements must conform if they are to achieve the action goal; regulates the spatial and temporal aspects of the movement

What are nonregulatory conditions?

Features of the environmental context that have no influence or only an indirect influence on movement characteristics

What is the intertrial variability?

An environmental characteristic that refers to whether the regulatory conditions associated with the performance of a skill change or stay the same from one trial to the next

What is a theory?

A principle used to explain phenomena, supported by data

What is a hypothesis?

An assumption made before an experiment has been done to test it

What is a model?

A physical and/or abstract representation of a specific aspect of a system linking a theoretical concept with experimental output and then used to formulate and test predictions of the theory

What is the reflex theory?

Movement is controlled by stimulus-response

What is the hierarchial theory?

Cortical centers control movement in a top-down manner throughout the nervous system. Sensory feedback is needed and used to control the movement while voluntary movements are initiated by “will”

What is the motor program theory?

Adaptive, flexible motor programs and generalized motor programs exist to control actions that have common characteristics

What are primitive reflexes?

Involuntary, brainstem-mediated motor responses present at birth that facilitate neonatal survival and early development

What is the primary purpose of primitive reflexes?

Survival and early sensorimotor behavior

What is a righting reaction?

Automatic postural reaction used to orient the head/body and restore alignment with gravity

What is an equilibrium reaction?

Automatic balance reaction to keep or restore the center of mass over the base of support

Equilibrium reactions and bipedal functions come from what neuroanatomical structure?

Cortex

Righting reactions and quadrupedal function come from what neuroanatomical structure?

Midbrain

Primitive reflex and apedal function come from what neuroanatomical structure?

Brainstem and spinal cord

What tract is associated with decorticate posturing?

Rubrospinal

Where is the lesion with decorticate posturing?

Above the red nucleus

What tract is associated with decerebrate posturing?

Vestibulospinal

Where is the lesion for decerebrate posturing?

Below the red nucleus

What is the decorticate posture?

Flexed UE and extended LE

What is the decerebrate posture?

UE and LE extended

What is the systems model?

Multiple body systems overlap to activate synergies for the production of movements that are organized around functional goals; it considers interaction of the person with the environment and goal-directed behavior

What is the dynamical systems theory?

Movement emerges to control degrees of freedom; functional synergies are developed naturally through practice and experience and help solve the problem of coordinating multiple muscles and joint movements at once; patterns of movements self-organize within the characteristics of environmental conditions and the existing body systems of the individual

What are ecological theories?

The person, task, and environment interact to influence motor behavior and learning; perceptual information

What are internal forces?

Muscle contractions, tensile forces in tendons and ligaments

What are external forces?

Gravity, ground reaction forces, and external weights or friction

What are key metrics?

Joint torques (moments), internal joint reaction forces, mechanical power, and work

What is kinematics?

Motion of the body without regard for forces

What is kinetics?

Forces that cause or result from motion

What is a degree of freedom (DoF)?

An independent variable that can change during movement; one task can have multiple movement solutions

What DoF strategy is used during early learning?

Freeze

What DoF strategy is used during intermediate learning?

Release

What DoF strategy is used during skilled performance?

Exploit

What is synergy?

A group of muscles showing covarying changes in activation level during movements to alleviate the problem of motor redundance; a reduction method to simplify control

What is a reflex?

Automatic response to a sensory stimulus

What is the voluntary control of a synergy?

Can be voluntary, automatic, adaptive, or pathologic

What does Latash or the Dynamical Systems Theory say about synergy?

It is not a fixed group of muscles that always fire together. Instead it is a task-specific neural organization in which multiple elements co-vary to stabilize an important performance output while allowing flexibility in the individual elements

What is the principle of motor abundance?

The body has more elemental variables than are strictly required to accomplish most tasks. It allows different combinations of elements to yield the same successful task outcome

What is grouping/organization?

Multiple elements are coordinated as a functional unit rather than independently controlled one by one

What is stabilization?

Elements co-vary so important task outcomes remain stable despite noise, perturbation, or changing individual contributions

What are individual constraints?

Strength, limb length, mass, joint stiffness, fatigue, pain, sensory capacity, and neural function

What are task constraints?

Goal, speed, accuracy, load, rules, and required base of support

What are environmental constraints?

Gravity, support surface, object properties, space, visual conditions, and social context

What is an attractor?

The system may settle into a stable movement pattern

What is the phase transition?

As a control parameter changes, the current pattern may become unstable and shift into another pattern

What is a synergy in the self-organization view?

An emergent coordination pattern formed by interacting constraints

What is the role of CNS with Latash’s view?

Imposes time-varying constraints and organizes elements around salient task variables

What is the role of CNS with self-organization?

It is one contributor among body, task, and environment; no single executive needs to prescribe the pattern

What is a motor program?

An abstract representation that, when initiated, results in the production of a coordinated movement sequence

What is a generalized motor program (GMP)?

Information about the order of events, the timing of events (temporal structure), the overall force of contractions, and the muscle(s) or limb(s) used in the movements

What is a complex motor program (motor plan)?

Idea or plan for purposeful movement that is made up of several component motor programs

What is nonlinear behavior?

One that transforms into a new configuration when a single parameter of that behavior is gradually altered and reaches a critical value

What are abnormal synergies?

Stereotypes, linked multi-joint movement patterns that commonly appear after an upper motor neuron lesion

UE flexion synergy components?

Scapular retraction, shoulder abduction, external rotation, elbow flexion, forearm supination, wrist and finger flexion

UE extension synergy components?

Scapular protraction, shoulder adduction, internal rotation, elbow extension, forearm pronation, and wrist and finger flexion (maybe extension)

LE flexion synergy components?

Hip flexion, abduction, external rotation, knee flexion, ankle dorsiflexion, inversion, and toe dorsiflexion

LE extension synergy components?

Hip extension, adduction, internal rotation, knee extension, ankle plantarflexion, inversion, toe plantarflexion

What spinal levels carry low-dimensional motor commands and innervate synergy-forming spinal modules S1 and S2?

C2 and C3

Connections from what spinal levels inhibit the contralateral motor cortex?

C4 and C5

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