Lecture 11 Constraints on Motor Control Flashcards

Question

Abnormal Synergies - Evaluation

Answer 1

* Observation - resting and with volitional movement Flexion synergy Extensor synergy * Fugl-Meyer Assessment (research heavy)

Answer 2

* The simultaneous activation of additional mm., often agonist and antagonist, during functional movements * Present in both novice learners as a normal control strategy * Also present following neurologic insult due to misdirected motor commands from injured sensorimotor areas of the brain

Answer 3

* Contributes to coordination of movement * Key role in smooth accurate movements * Eye hand coordination * Movement timing * Force and Postural control * Regulator of motor output * Error detection and correction * Intended movement from cortex to cerebellum * Actual movement (sensory feedback) * Correction to motor tracks

Answer 4

* Does not play primary role in motor function * Signs and Symptoms of Cerebellar Pathology: Hypotonia Ataxia/discoordination of voluntary movement Intention tremor * May also see: dyssynergia, dysdiadochokinesia, dysarthria, and impaired oculomotor control * Regulation of cognition, emotion, and autonomic function may be affected

Answer 5

* Reduction in stiffness of a muscle to lengthening * Classic sign of cerebellar dysfunction, though also used for spinocerebellar lesions and developmentally delayed children * Acute cerebellar damage affects regulation of muscle spindle sensitivity * Associated with pendular reflexes

Answer 6

* Sequencing, timing and grading of activation of multiple muscle groups for movement * With cerebellar pathology, lose coordinated coupling between synergistic muscles and joints; called discoordination * Incoordination (Ataxia): movements that are awkward, uneven, or inaccurate ## Footnote Questions we ask: Does patient have difficulty under or overshooting a target? Is the movement smooth and fluid or jerky (shaky)?

Answer 7

* Reaction time: Delay in onset of movements * Dysmetria: Errors in range and direction of movement Hypometria: Underestimation of the required force or ROM (undershooting) Hypermetria: Overestimation of the required force or ROM (overshooting) * Dysdiadochokinesia: Inability to sustain regular rhythmic movements * Difficulty with termination of movement

Answer 8

* Finger to nose, heel to shin * Repeated motions, practice of functional task-specific movement with increasing accuracy and time demands * Feedback * Weight-bearing activities * Rapid alternating movements (RAM) * Movement to music or metronome * Icing or tapping (sensory stimulation)

Answer 9

* Many therapeutic techniques used to treat coordination challenges * Some considered “general” approaches to discoordination * Others more specifically target problems in: Timing Sequencing Grading synergistic muscle activity (high reps to get the most information to them) * Most common technique is repetition and practice of a functional task-specific movement

Answer 10

* Tremor: Rhythmic involuntary oscillatory movement of a body part * Intention tremor: Occurs during the performance of a voluntary movement Characteristic of pathology of cerebellum Frequency of less than 5Hz, most marked at the end of a movement

Answer 11

* Damage to the cerebellum affects the extent and rate at which individuals adapt movements to new context * Training may require longer duration or intensity of practice to improve function WHY? - shift up the brain levels, ## Footnote uses sensorimotor adaptaion

Answer 12

A change in motor behavior that is driven by sensory prediction errors * Actual sensory consequence of a movement differs from the predicted sensory consequence of that movement * Unexpected task demands or changes in environment that require modifications to the executed motor program * Low cognitive load

Answer 13

* Situated in cerebrum and midbrain * Motor circuit contributes to preparation for and execution of movement * Modulation of movement * Role in selective activation of some movements and suppression of others * Control of antagonist muscles during movement * Control of force * Suppression of unwanted movements

Answer 14

* Hypokinetic disorders: Parkinson’s disease (PD), Dystonic Cerebral Palsy (CP); characteristically slow or diminished movement. Bradykinesia, hypokinesia, akinesia Rigidity Dystonia * Hyperkinetic disorders: Huntington’s disease (HD) Chorea, Athetosis; characterized by excessive involuntary movement and decreased muscle tone (hypotonia) Resting tremor Kinetic tremor

Answer 15

* Akinesia - inability to initiate movement/reduction in spontaneous movement * Hypokinesia - reduced frequency and amplitude of spontaneous or automatic movements (micrographia, mask-like expression, reduced arm swing) * Bradykinesia - Slow initiation and execution of movements (RAM - progressively reduced amplitude until no motion) * Will affect procedural learning

Answer 16

* Heightened muscle resistance to passive movement * Predominant in flexor muscles * Lead pipe rigidity - Constant resistance to movement throughout the entire range of motion * Cogwheel rigidity - Alternating episodes of resistance and relaxation, or “catches”, as the extremity is moved through ROM

Answer 17

* Resting tremor - Occurs in a body part that is not voluntarily activated and is supported against gravity, though can increase with mental stress and with movement of another body part “Pill-rolling”, continuous oscillatory motion of fingers Frequency of 4-6 Hz * Postural tremor - With voluntary maintenance of position against gravity * Kinetic tremor - Occurs during voluntary movement of a body part, such as moving your wrist up and down Simple Kinetic Tremor – Not target related Intention tremor – Target-directed movement

Answer 18

* Choreiform movements – involuntary, rapid, irregular, and jerky movements that result from BG lesions * Athetoid movement – Slow involuntary writhing and twisting movements * Usually UE > LE * May include neck, face, and tongue * Athetoid CP – Second most common form of CP

Answer 19

* Syndrome dominated by sustained or intermittent muscle contractions frequently causing hypertonia, twisting and repetitive movements, and abnormal postures * Initiated or worsened by voluntary action Associated with overflow muscle activation * Co-contraction of agonist and antagonist muscles * Basal ganglia primarily, though can occur with lesions in thalamus, cerebellum, and brainstem

Answer 20

* reward and dopamine cant be used with this population

Answer 21

Improvement in motor behavior that is driven by binary outcome-based feedback * Depends on extrinsic feedback about the outcome of the task goal; Knowledge of Results * Likely due to basal ganglia involvement; reward-based dopamine signaling * Moderate-high cognitive load ## Footnote Not good for basal ganglia injuries.

Answer 22

* Physical Activity necessary to maintain muscle and bony skeleton * Without, can have muscle atrophy, deconditioning, contractures, DJD, and osteoporosis * Muscle paresis and weakness → muscle atrophy → decreased gait speed → reduced physical fitness * Normal aging (sarcopenia) also contributes to these impairments and can further increase risk of falls, etc.

Answer 23

* Changes in the physical properties of the muscle Positioning in shortened position = muscle unloading, increased likelihood of contracture Muscle unloading = Atrophy, loss of sarcomeres, accumulation of connective tissue (CT), increase in fat deposits in tendons * Changes at the joint Proliferation of CT into joint space, adherence of CT to cartilage surfaces, atrophy of cartilage, and disorganization of ligament alignment * Changes at the bone Reduction in bone mineralization = osteopenia or osteoporosis

Answer 24

* Major factor contributing to motor control problems following CNS injury * Type of problem depends on location and size of lesion Somatosensory Visual Vestibular

Answer 25

* Associated with significant loss of function and impaired motor learning * Related to longer hospital length of stay following CVA * Predictive of recovery of function: 2-point discrimination = Poor recovery of UE dexterity Poor proprioception = Poor recovery of functional UE movement Light touch + proprioception = Poor recovery of ADL function * Abnormalities in the brain’s ability to integrate sensory information may interfere with motor program processing

Answer 26

* Impairments range from 11-85% * Primary somatosensory (SS) cortex Results in CL loss of touch and proprioception, but not temperature or nociception * Anterior parietal cortex Results in severe difficulties with touch threshold, vibration, joint position sense, two-point discrimination * Posterior parietal cortex Mild difficulty with simple tactile tests and SIGNIFICANT difficulty with complex tactile recognition tasks * Secondary SS cortex Complex tactile discrimination tasks (stereognosis)

Answer 27

* Dorsal column/medial lemniscus lesions of spinal cord Loss of discriminative touch, light touch, kinesthesia * Anterolateral lesions of spinal cord Loss of pain, temperature, coarse touch and kinesthesia

Answer 28

* Depth perception: The ability to see things in three dimensions (including length, width and depth), and to judge how far away an object is from you * Oculomotor control: Muscular control to facilitate depth perception, visual attention, visual memory, visual perceptual tasks, visual scanning, spatial orientation, eye-hand coordination, balance, or reading and writing tasks * Visual fields: The entire area (field of vision) that can be seen when the eyes are focused on a single point * Acuity: Sharpness of vision: Measured by the ability to discern letters or numbers at a given distance according to a fixed standard

Answer 29

* Disorders of the visual system will vary according to the location of the lesion * CVA: * ``R occipital lobe – Visual field deficit, homonymous hemianopsia, or the loss of visual information in one hemifield * ``R Parietal lobe – homonymous hemianopsia, may develop hemispatial neglect

Answer 30

* Disorder caused by damage to the parts of the brain that process vision * Cannot be attributed to ocular or visual pathway impairments (peripheral) * Common Visual Behaviors for CVI Delayed response to visual stimulus (Latency) Poor visual attention Blunted or avoidant social gaze Light gazing Difficulty with visual complexity Fatigability Better response to familiar vs. novel stimuli Objects viewed at strange angles Heightened or dulled response to movement Drawn to saturated color (yellow, red…)

Answer 31

* Information re: head movements and position with reference to gravity * Information is used for gaze stabilization, posture, and balance * Contributes to conscious sense of orientation in space

Answer 32

can result in: * altered/diminished gaze stabilization * altered posture and postural control * vertigo and dizziness

Answer 33

* Perception: Integration of sensory impressions into psychologically meaningful information * Body image and body scheme disorders (primary perception deficits) * Decreased awareness of body parts and their relationship to each other and to the environment * Unilateral neglect: inability to perceive and integrate stimuli on one side of the body (CVA)

Answer 34

* Difficulty perceiving oneself in relation to other objects, other objects in relation to self, and objects in relation to each other * E.g., position in space (over, under, beside, behind, etc.), figure ground discrimination * Can include Hemineglect

Answer 35

* Apraxia: The inability to carry out purposeful movement in the presence of intact sensation, movement ability, and coordination * Limb apraxia: Ideomotor: Difficulty with translating an idea into movement; Understand task and what is asked of them, but no kinetic memory on how to do task Ideational: “No idea” about the task; Inability to formulate or organize a plan of action even though movement is possible; Will not understand how to use a tool * Occur in patients with lesion in **Left** hemisphere

Answer 36

* Characteristics of the praxis system include the following: 1. It is most often lateralized to the left hemisphere. 2. It serves to store skilled motor information for future use. 3. It facilitates interaction with environment. 4. It provides a processing advantage so that new planning is not required each time an activity is started. storage system for motor programs.

Answer 37

* Attention: Inability to focus on specific stimulus without being distracted Attention to task and motivation are critical for motor learning * Orientation: Decreased understanding of person, place, time, situation * Memory: Decreased ability to process, store and retrieve information

Answer 38

Problem Solving * Decreased ability to manipulate and apply knowledge to new or unfamiliar situations * Decreased ability to understand problem, generate solutions, evaluate solutions Arousal and Level of Consciousness * Must be alert to respond to stimuli in environment * behavior is heavily dependent on arousal

Answer 39

* Lesion in different areas of the brain will result in widely differing impairments * As PT’s we need to be able to assess and treat these impairments and address the impact they will have on patient ability to function

Lecture 11 Constraints on Motor Control Flashcards

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